1-TESMM-Tecumseh Engine Service Maintenance Manual

1-TESMM-Tecumseh Engine Service Maintenance Manual

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TECUMSEH T E C H N I C I A N ' S

H A N D B O O K

This manual covers all Tecumseh Peerless® gear products as follows: 100 Series Differentials MST200 Series Transaxles 300 Series Transaxles 600 Series Transaxles 601 Slow Speed Transaxle 700 Series Transmissions 700H Series Transmissions 800/801 Series Transaxles 820 Series Transmissions 900 Series Transaxles 910 Series Transaxles

915/940 Series Transaxles 920 Series Transaxles 930 Series Transaxles 1000/1100 Series Right Angle/T-Drives 1200 Series Transaxles 1300 Series Transaxles 2300 Series Transaxles 2400 Series Transaxles 2500 Series Transaxles 2600 Series Transaxles VST Transaxles

TECUMSEH & PEERLESS TRANSMISSION and DRIVE PRODUCTS

ENGINES & TRANSMISSIONS

Form No. 691218 R 1/02

IMPORTANT NOTICE! SAFETY DEFINITIONS Statements in this manual preceded by the following words are of special significance:

or

WARNING indicates a potentially hazardous situation which if not avoided, could result in death or serious injury. NOTE Refers to important information and is placed in italic type.

It is recommended that you take special notice of all items discussed on each page and wear the appropriate safety equipment.

TABLE OF CONTENTS Page CHAPTER 1 Model Overview and Terms Used ...................................................................................... 1 - 6 Lubrication Chart ..................................................................................................................... 7 Torque Values Chart ................................................................................................................ 8 Identification ............................................................................................................................. 9 Trouble Shooting Table ................................................................................................... 10 - 12 CHAPTER 2 300 Series Transaxles .......................................................................................................... 13 CHAPTER 3 600 Series Transaxles ................................................................................................... 14 - 18 601 Slow Speed Transaxle ................................................................................................... 19 CHAPTER 4 700 Series In-Line Shift Transmission ............................................................................ 21 - 25 700H Series Transmissions ........................................................................................... 26 - 29 CHAPTER 5 800/801 Series Transaxles ............................................................................................. 30 - 36 820 Series Transaxles .................................................................................................... 37 - 41 CHAPTER 6 900 Series Transaxles ................................................................................................... 42 - 46 CHAPTER 7 910 Series Transaxles .................................................................................................... 47 - 50 CHAPTER 8 915 Series / 940 Series Transaxles ............................................................................... 51 - 55 CHAPTER 9 920 Series Transaxles .................................................................................................... 56 - 60 CHAPTER 10 930 Series Transaxles .................................................................................................... 61 - 65 CHAPTER 11 MST200 Series Transaxles ............................................................................................ 66 - 70 Checking Oil Level................................................................................................................. 71 CHAPTER 12 1200 Series Three-Speed Transaxles ............................................................................ 72 - 74 CHAPTER 13 1300 Series Hydrostatic Gear Reduction Differentials ................................................... 75 - 77 CHAPTER 14 2300 Series Four-Speed Transaxles .............................................................................. 78 - 84 CHAPTER 15 2400 Series Hydro Powered Transaxles ........................................................................ 85 - 87 CHAPTER 16 2500 Series Hydro Powered Transaxles ........................................................................ 88 - 92 CHAPTER 17 2600 Series Hydro Powered Transaxles ........................................................................ 93 - 97 CHAPTER 18 Differentials .................................................................................................................. 98 - 103 CHAPTER 19 Drives ......................................................................................................................... 104 - 108 CHAPTER 20 1100 Series Drives ..................................................................................................... 109 - 113 CHAPTER 21 Shifting Assembly ....................................................................................................... 114 - 116 Shift Key Quick Reference Guide ........................................................................................ 117 CHAPTER 22 Bearing and Bushing Service ..................................................................................... 118 - 119 CHAPTER 23 VST Troubleshooting .................................................................................................. 120 - 121 C

Tecumseh Products Company 2002

CHAPTER 1. MODEL OVERVIEW AND TERMS USED TECUMSEH/TRANSMISSIONS UNITS GENERAL Manufactured since 1945, Tecumseh/Peerless gear products are found in many products worldwide. Applications vary from industrial products to residential and commercial lawn and garden equipment. This book is intended for use by properly trained technicians that have appropriate facilities and the proper tools. If you are not a Tecumseh trained technician, DO NOT attempt a repair. Consult an Authorized Tecumseh Servicing Dealer. IDENTIFICATION OF MODELS All units manufactured since 1964 have identification numbers located on an attached tag or are stamped into the case. This information is required to obtain parts or replacement units. We have included illustrations on page 9 of this book to assist you in locating them. TRANSAXLES The term transaxle is a combination transmission and differential in one case. Tecumseh transmissions and transaxles are manufactured in many different gear ratio combinations from one to seven forward speeds with one reverse. 600 Series The 600 series is a lightweight transaxle used in riding mowers or similar applications. The 600 series has a vertical input shaft at the top of the aluminum case. Variations in the series (which determine the specific model number such as 603, 603A, 609 etc.) include: 1. 2. 3. 4. 5.

Shift lever shape. Axle lengths. Axle machining for wheel hub attachment. Axle housing variations. Size of the brake shaft.

There may be other slight differences, however, these are present as a result of product improvement which are not options to an O.E.M. (Original Equipment Manufacturer). 800 Series This unit has 3 to 6 speeds forward and 1 reverse. This transaxle features bronze oil impregnated bushings with needle bearings or ball bearings on the axles, input and output shafts.

900 Series This unit is similar to the 800 series transaxle with the added feature of 2, 3, or 4 speeds forward and 1 reverse. 910 Series The 910 series transaxle offers a forward and reverse unit. The speed changes with the use of a variable-drive pulley arrangement. 915/940 Series This unit has 3 to 5 speeds forward and 1 reverse. Reverse is gear driven instead of chain driven and the case is contoured around the gears. 920 Series The 920 series offers 3 to 7 speeds forward and 1 reverse. The shifter/brake shaft is similar to the 800 series shifter/brake shaft. 930 Series This unit has 3 to 7 speeds forward and 1 reverse. The transaxle is very similar to the 920 series except the differential and shifter/brake shaft are different. The MST Series The MST (Manual Shift Transaxle) is a sealed unit which uses 16 oz. (473 ml) of 80W90 gear lube (part #730229B). The MST series is available with up to 6 speeds forward and one reverse and has a contoured case and cover. 1200 Series The distinguishing feature of the 1200 series transaxle is that the axle support housings are pressed in from the inside of the case and cover. Therefore they are not readily removable until the unit is completely disassembled. The case is cast iron for rugged, longtime use. 2300 Series Generally similar to the 1200 series transaxle. The distinguishing features are a more massive case and a larger shift lever opening machined area. The obvious difference from the standpoint of application is that these units have four speeds forward and will be found on equipment that can be used with ground engagement operations. NOTE: The 1200 and 2300 series transaxles are fairly similar in appearance, but do have recognizable characteristics. Both of these units have cast iron cases for rugged applications, although the 2300 series is the only unit that can be used with ground engaging applications.

820 Series With 2 to 6 speeds forward and 1 reverse, this transaxle is built for heavy duty applications including use with ground engaging attachments. Sleeved needle bearings are used in place of oil impregnated bushings on all shaft ends and ball bearings are standard on the axles. The 820 also features steel cut gears for maximum durability.

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HYDROSTATIC GEAR REDUCTION AND DIFFERENTIAL UNITS GENERAL These units do not have a transmission function characteristic of transaxles, but rather, are designed to reduce input speed to a suitable axle speed and torque range. The hydrostatic units which mate to these units perform the transmission function. 1300 Series This unit is the hydrostatic counterpart of the three-speed forward unit (1200). It has an aluminum casing and pressed-through axle support housings, which is characteristic of the 1200 series. The hydrostatic pump is made by Eaton® Manufacturing and is not serviced by Tecumseh Service Dealers. 2400, 2500 & 2600 Series This series of hydrostatically driven reduction gear and differential units can be used in ground engaging operations such as plowing. The hydrostatic pump is manufactured by Sundstrand® Corp. TRANSMISSIONS Transmissions manufactured by Tecumseh consist of a shifting mechanism to take a constant input shaft speed and reduce it to the desired output speed. Transmissions need a belt drive or chain drive/differential assembly to deliver power to the wheels. 700 Series This unit can be 2, 3, 4, 5 & 6 speeds forward and 1 reverse. The brake system can be mounted on either side of the unit. 700 “H” Series This unit is built with almost all interchangeable parts within its two cases except with an “H” shift pattern. This unit has 3 or 4 speeds forward and 1 reverse. DIFFERENTIALS The 100 series is a self-contained differential/axle unit. It features hardened or non-hardened axle shafts of various lengths and is machined with many variations for hub attachment. The case is cast aluminum and the differential gears are sintered metal (powdered metal) or cut steel. The differential pin is held in place by the four retaining cap screws. Oil Lite bushings reduce friction during differential operation. The drive sprocket is part of the unit which, depending upon the application, can be of several diameters in size thus having a different number of gear teeth. This sprocket is often supplied by the O.E.M. ANGLE DRIVES These units are used primarily to change the direction of drive at the point where the working equipment attaches. They can be assembled for right or left hand rotation so that they can be used in various combinations for synchronous operation.

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Right Angle Drives These units consist of input shafts, output shafts, and the beveled gearing necessary to change the direction of power at right angles. If the bevel gear (drive gear) on the input shaft is turned around and moved to the other side of the case (opposite end of the shaft), the output shaft will rotate in the opposite direction. A cover identifies each unit as being either a left hand (LH) or a right hand (RH) right angle drive. The cases and bearings are identical in both drives. “T” Drives The “T” drive is essentially the same as the right angle drive except that the input shaft extends out the other side of the case to transmit power in the same line to additional right angle drives or other equipment. Shafts, Couplings, Pulleys, etc. These items are part of complete units and are used to connect angle drives, and other attachments. The serrated couplings match the serrations on the shafts of the angle drives and connecting shafts.

TERMS USED AXLE - The shaft which connects the wheel or hub to the differential unit and transmits force back to the wheels. AXLE HOUSING (or AXLE SUPPORT) - An extension of the case and cover to support the outer ends of the axles. Because the housing is visible, it is often the best means of distinguishing the series in question. BEARING BLOCK (Strip) - Used to support the ring gear of the differential. BEVEL (on a gear) This is a chamfer or roundness of the meshing side of the gear teeth to permit easy shifting. For instance, with "H" shift pattern transaxles, this is about the only allowance that can be made to make shifting easier. Input power should be stopped before shifting to keep these spur gears from developing wear. BEVEL GEAR - A gear with teeth ground on a diagonal so that when it meshes with a second bevel gear, power is transmitted at an angle. If the angle is 90o, the gear is known as a MITER GEAR. BEVEL PINION - The smaller of two meshed bevel gears in a gear train. BRAKESHAFT/SHIFTER BRAKESHAFT) - The shaft on a unit (Transaxles or Transmission) to which a braking system may be attached. It is usually larger in diameter than the input shaft due to its function of taking shock loads experienced in braking.

CASE - That bottom half of the gear box which contains the shift lever , axle and brake shaft openings. The other half is the COVER. Unit reassembly is normally done into the case with variations listed by individual model. CHAMFER - In gear products, chamfers provide two main functions. The first is to reduce gear wear at the leading contact point as two gears mate. The second purpose is to act as a ramp for shifter key compression through the shift washer prior to gear engagement. The chamfer in the washer is either stamped or machined in. COUNTERSHAFT - A splined shaft which hold spur gears that are in constant mesh with shift gears and transfer input power to the shift gears. COUPLING - A sleeve to connect two serrated or splined shafts in the same axial plane. Used in right angle drive systems, 700 series, output shafts or in a hydrostatic drive connecting the pump and motor to the gear drive of a transaxle. COVER - The top half of a horizontally parting gear box such as 700,800,900 and MST models. The cover normally contains the input shaft, bearing(s) and the input bevel gear. The shaft may change location in the cover based on the OEMs mounting position. DIFFERENTIAL GEAR BOLTS - Through bolts holding the differential parts together. The heads of these bolts must be opposite the output shaft gear (except in the 2400 series). This is an early check to see that the unit is being assembled correctly. DOWEL PIN - An alignment pin used to align the case and cover and other parts in a transmission or transaxle. The dowel pins should be installed to hold the parts in alignment before tightening the retaining screws. Failure to install dowel pins first will usually lead to a unit that binds after assembly. DUO-TRAK™ DIFFERENTIAL (Trademark -Illinois Tool Works) - A type of differential which increases torque to the tractive wheel to keep it turning. However in situations where differentiation is necessary (as in turning), the unit acts much like a regular differential. EQUIPMENT - The complete assembled product (riding mower, tractor etc.) which uses of the drives listed in this manual. HEAD ASSEMBLY - A complete unit containing all parts of one right angle or “T” drive assembly of a right angle drive system. The head assembly is permanently lubricated and sealed. IDENTIFICATION NUMBER - See MODEL NUMBER IDLER - A gear used in a gear train to transfer motion or direction. The gear rotates independently of the shaft upon which it is located.

INPUT OR INPUT SHAFT - The part of a unit which is always connected to the drive. Its rotational speed is dependent on the driving mechanism. The input shaft brings power to the unit.

LIMITED SLIP DIFFERENTIAL - See DUOTRAK™ DIFFERENTIAL. MITER GEAR - One of a pair of interchangeable bevel gears with axles at right angles. Since all bevel gears are miter gears, the terms can be the same. MODEL NUMBER - The identifying number of a unit which will permit selection of the proper parts to repair that unit. NEUTRAL SPACER - A single or split collar between forward and reverse gears that the shift keys engage into when the unit is in neutral. OIL SEAL, SINGLE LIP/DOUBLE LIP - An oil seal with one or two sealing surfaces to prevent entrance of foreign matter and leakage of lubricant. OIL SEAL, (SQUARE CUT O-RING)- A seal with two external and two internal sealing surfaces. Used in the shifter housing. OUTPUT, OR OUTPUT SHAFT - On a transaxle, the shaft that contains the output pinion which is in direct mesh with and drives the differential. The output shaft on a transmission contains the sprocket for driving the axles. The output shaft is driven by the large OUTPUT GEAR. OUTPUT SHAFT GEAR - The importance of defining this gear is to point out that it must be opposite the differential bull gear (except the 2400 series). GEAR REDUCTION AND DIFFERENTIAL UNIT - A unit that reduces a high R.P.M. input speed to a suitable axle speed without the use of a transmission. Since there is a single gear train, there is a single input speed to output speed ratio, however, axle speeds are infinite, depending upon input speed. REVERSE IDLER (915 Series) - The gear located between the reverse gear of the countershaft and the reverse gear of the shifter/brake shaft that allows the drive to operate in the opposite direction. REVERSE IDLER - A gear added to the gear train so when in mesh, the direction of all gears driven after it is reversed. Its number of teeth also affects the reverse gear ratio. The center gear of the three gear cluster is always in mesh with the REVERSE IDLER, and the large shifter gear always shifts into it. RIGHT ANGLE DRIVE / HEAD ASSEMBLY. The major operating parts are a pair of miter gears. The assembly consists of other right angle or “T” drive head assemblies and connecting hardware.

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SEAL - A material which prevents lubricant from leaking past a rotating shaft. It can be a rubber or square cut "O"-ring, a sealing-type ball bearing, or most commonly, a rubber sealing surface encased in a metal form. SEAL RETAINER - Found on some models of transaxles and on right angle drives.

SHIFTER HOUSING (600/2300's) - This housing contains the shift lever and must be re-installed in the proper position to function correctly. If the housing does not already have guide marks, scribe the shifter housing and transmission case before removal.

SHIFT COLLAR - A round collar which retains shift keys onto the shifter/brake shaft. The shifter assembly pin (or pins) slide into the groove on the collar to move the shift keys.

SHIFTER ROD - One of two similar smooth rods of equal length with grooves which match the fork positioning with meshed positions of the shifter gears and those of the three gear cluster. Each rod has a snap ring to act as a fork stop, but can also be used to determine how the fork is assembled to it.

SHIFT GEARS - The gears on the shifter/brake shaft that are in constant mesh with the spur gears of the counter shaft. The shift gear is engaged by the shift keys and it's size determines the speed of output by the axles.

SHIFTER SHAFT - A splined shaft which meshes with the internal splines of the shifter gears, to transmit force to the output shaft gear. On in-line transmissions and transaxles the shaft has machined channels to accommodate the shift keys.

SHIFT KEY - One of either two or four metal spring steel keys, which are held in the keyways of the shifter/ brake shaft by a shift collar. The shift keys are used to slide through the shift gears and engage the desired gear or speed.

SHIFTER STOP (600/2300's) - A stamped metal plate which separates the shifter forks. The stop has a notch cut in it which corresponds to the neutral position on the shifter forks and rod. The shifter lever must return the engaged fork back to neutral before it can actuate the other fork.

SHIFT KEYWAY - One of either two or four slots in the shifter/brake shaft for the shift keys to slide through for gear selection. SHIFT WASHER - The shift washer provides a ramp to gradually compress the shift key prior to engagement with the gear. We have used two types in production; the newer style has the chamfer stamped into the washer. Earlier production washer’s had the chamfer machined in. SHIFTER ASSEMBLY - Consists of a shift rod, shift fan, shift arms and shift pin or pins. SHIFT LEVER - The lever by which the operator manually changes the shifter gears to vary reduction speed ratios in the transmission. The configuration of the lever is variable and is often the only reason for a unit being given a new model number. SHIFTER FORK - A mechanical arm which is connected to the shifter rod to position the shifter gear at an exact spot axially along the shifter shaft. SHIFTER GEAR, LARGE (600/2300) - This gear transmits 1st gear, reverse gear (and 2nd gear in 4speed units) ratio force to the output shaft. It is beveled on both sides. SHIFTER GEAR, SMALL (600/2300) - This gear transmits 2nd and 3rd (3rd and 4th in a 4-speed unit) gear ratio force to the output shaft. It can have two different beveled tooth diameters or it can have a beveled spline to engage 3rd (or 4th) gear through an additional splined shaft.

SPROCKET - A geared wheel designed to turn a chain drive. Sprocket diameters vary and are available in different sizes for changing output ratios. SPUR GEAR - A gear having the shaft bore and teeth in a parallel plane. “T” DRIVE - A right angle drive with an input shaft extending thru the case to transmit power axially in a second direction to the right angle output. On “T” drives with dissimilar input and output ends, care must be taken to insure that the parts do not run in reverse when reassembled. THREE GEAR CLUSTER (2300) - A three gear assembly in mesh with the input shaft. The gears are of different sizes to change gear ratios when meshing with the two shifter gears. THRUSTER RACE - A thrust washer in which the outer edge is cupped to fit the outer diameter of a thrust bearing. This fit positions the thrust race concentric with the axle diameter. It further acts as a thrust washer. THRUST WASHER - A flat polished surface separating metals of different hardness. It also acts as a spacer between shafts and the case and cover. TRANSMISSION - A system of varying sized gears in a case, some of which can be moved along a shaft to vary the gear ratio in a unit. The net effect is to change speeds to the rear wheel according to the type of work being done. UNIT - A general term for Tecumseh/Peerless Transmission products.

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GENERAL SERVICING PROCEDURES The following service procedures should be understood and practiced whenever service is needed on a Tecumseh transmission or drive product. WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury. WARNING

Before removing a unit (Transmission product) from any equipment, look for and ask the customer about: 1. Loose, worn or glazed drive belts. 2. A misadjusted or badly worn clutch or belt tension. 3. Loose/lost set screws and or sheared keys in drive, driven pulleys or axle. 4. Oil saturated drive belts or clutches. 5. Bad operating habits, such as clutch riding or not clutching when shifting. 6. Oil leaks. 7. If possible operate the equipment to help isolate the problem. 8. Review Service Bulletin 304. Removal of the unit from the equipment:

3. Remove the shift housing and drain the lubricant from unit. Observe the old lubricant to see if metal particles are present. 4. Check axle shafts carefully for smoothness. Use crocus cloth or a Scotch-Bright™ pad to rub down high spots and eliminate rust or paint from the shafts. 5. Check the model and specification number and remember to have the exploded parts diagram accessible during disassembly. 6. Have on hand seal protectors, drivers, shop cloths, appropriate tools and this technicians handbook while servicing a unit. OIL LEAKS, SEAL AND GASKET SERVICE Tecumseh units contain various styles and sizes of oil seals. The function of any oil seal is to seal inward to prevent lubricant leaks and prevent outside debris from entering the unit. Seals can be single lipped with the sealing edge facing inward or double lipped sealing inside and out. GUIDELINES TO REMEMBER 1. Other than leaking seals, gaskets and “O” rings, leakage can occur due to a cracked case or cover, flats on shafts, porosity (rarely, if ever), and worn bushings and shafts. 2. Replace ALL seals/gaskets if disturbed. The small cost of installing new seals is small in comparison to a dissatisfied customer and the cost of rework. 3. Some seals have a "Redicoat" sealant applied, while others may need a thin coat of RTV silicone to the outer shell upon installation.

1. Raise the equipment so the transmission or transaxle is accessible. Use wood blocks to prevent equipment from shifting. Do not use bricks, cement or cinder blocks. 2. Visually inspect the Tecumseh unit for oil leaks, a cracked housing, binding or rubbing of parts, or other symptoms of malfunction. 3. Use a jack under the unit to support it’s weight when attachments are removed. 4. Remove wheels, drive belts, pulleys, chains and other associated equipment from the unit. Be aware of positioning of parts. Use a scribe mark, if in doubt, to reassemble parts quickly and accurately. 5. If the shifter lever will interfere with removal of the unit in anyway, remove it before unit removal. These can easily be bend out of shape. 6. Remove all attached hardware holding the Tecumseh/Transmission unit to the equipment on the case, cover, axle supports, brake and shifter. 7. Remove the unit from the equipment.

4. The surface over which the seal makes contact must be free of all cuts, scratches, high spots and rust. The shafts should be smooth, shiny and a thin film of light oil applied. Seal protectors must be used to clear keyways, splines, or other machined sharp edges on the shafts.

Preparing for disassembly of a unit:

Under-tightening fasteners can cause oil leakage, loosening of attaching parts, and possible shifting of the internal parts which may bring about a complete failure.

1. Visually inspect for evidence of oil seepage, tampering, misalignment, freedom of rotating shafts, etc. 2. Clean the unit thoroughly of any dirt, oil and debris.

TORQUE VALUE TROUBLESHOOTING GUIDELINES ALWAYS torque all fasteners to the appropriate value as listed in Chapter 1 page 9. Over-tightening can strip the threads in the cases or on a fastener. It also can over-compress gaskets, and possibly cause binding in the unit. A cross-tightening sequence to half the torque then finally to full torque value is a recommended procedure to prevent comebacks (repair returns).

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BASIC TESTING The absence of binding and oil leakage are the best indications that the unit has been properly reassembled. Though other, more elaborate tests can be done, the following procedures are accurate and the preferred method for a quick check of the unit. On an "H" shift pattern drive with the shift forks in neutral, rotate both axle ends in the same direction. They should turn smoothly although a little effort may be necessary. The brake shaft should rotate whenever the axles turn together, but in neutral, the input shaft should not turn. By moving any shifter gear into mesh, a greater drag should be felt on the axles, and both the input and brakeshaft should turn. For ease in turning the various shafts, insert a tool (such as a punch or a socket head screw key) into the keyway, however, do not force if the shaft is binding. Potential reasons for binding in the unit could be: 1. Gaskets were left out on reassembly or installed incorrectly. 2. Oil seal retainers, differential, thrust washers, shifter stop or oil seal retainers were installed improperly. 3. The shifter assembly or spacers were installed incorrectly. 4. Foreign matter could be blocking the gear teeth that are in mesh. 5. The input shaft was not properly seated in the case. 6. The case and cover could be mis-aligned (dowel pins were missing). 7. The bearing(s) do not have the lock tabs or notches in the correct position. For more information, consult the troubleshooting section.

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LUBRICATION CHART Check the Transmissions unit model and specification number before filling with lubricant. There may be a difference in the quantity recommended. This is dictated by the design of the vehicle and position of the transmission unit installed.

Model No. 300 600 800 801 820 900 910 915/940 920 930 1200 1305 1309 1313 1301 1302 1303 1304 1306 1307 1308 1310 1311 1312 1314 1315 1316 1317 1318 1320 1321 1322 1325 1328 1329 1319 1323 1326 1327 MST 2300 2400 2500 2600

Quantity Sealed 24 oz./710 ml Oil 30 oz./887 ml Grease 36 oz./1065 ml Grease 36 oz./1065 ml Grease 26 oz./769 ml Grease 18 oz./532 ml Grease 10 oz./296 ml Grease 30 oz./887 ml Grease 30 oz./887 ml Grease 48 oz./1420 ml Oil †† 32 oz./946 ml Oil

Model No. 700 700H 2800

Quantity 12 oz./355 ml Grease 12 oz./355 ml Grease †

Model No. All Models Except * *1408-P91 *1409-P91 *1410-P91 *3002 *3003 *3028 *3029 *3035 1000 Series 1100

Quantity 4 oz./118 ml Grease

3 oz./89 ml Grease

6 oz. / 180 ml SAE E.P. 80W90 Oil 16 oz./473 ml Oil

DIFFERENTIALS All Models 3 oz./89 ml Grease TWO SPEED AXLE All Models 2 oz./59 ml Grease THREE SPEED AXLE All Models 2 oz./59 ml Grease

44 oz./1301 ml Oil

NOTICE Grease: Bentonite Grease Part Number 788067C Oil: SAE E.P. 80W90 Oil Part Number 730229B 24 oz./710 ml Oil

† Refer to O.E.M. Technician’s Manual for type of lubricant and capacity system †† To be filled through shift lever opening

16 oz./473 ml Oil 64 oz./1892 ml Oil 32 oz./.946 ml Oil † †

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TORQUE VALUES CHART MODELS PART

AFFECTED

IN-LBS

FT-LBS

NM

Bolt 5/16-18 (Housing) Nut 5/16-18 (Housing)

100 Series 100 Series

228-264 120-156

19-22 10-13

25.8 - 29.9 13.6 - 17.7

Bolt 1/4-20 (Case to Cover)

600 Series

84-108

7-9

9.5 - 12.2

Bolt 5/16-18 (Axle Support Housing)

600 Series

156-180

13-15

17.7 - 20.4

600 Series 600 Series 800 & 900 Series (Except 820) 800, 900 & MST Series

84-108 84-108

7-9 7-9

9.5 - 12.2 9.5 - 12.2

90-100 85-110

7.5-8.3 7.1-9.2

10.2 - 11.3 9.7 - 12.5

Bolt 5/16-18 (Case to Cover) Bolt 1/4-20 (Bearing Cap) Bolt 1/4-20 (Differential) Bolt 1/4-20 (Brake Disc)

820 Series 820 Series 820 Series 820 Series

180-216 90-100 84-120 85-110

15-18 7.5-8.3 7-10 7.1-9.2

20.4 - 24.5 10.2 - 11.3 9.5 - 13.6 9.7 - 12.5

Bolt 5/16 x 18

1100 Series

180-216

15-18

20.4 - 24.5

Bolt 5/16 x 18

2800 Series

180-216

15-18

20.4 - 24.5

Bolt 1/4-20 (Case to Cover) Bolt 1/4-20 (Shift Lever Housing) Bolt 1/4-20 (Differential)

1200 Series 1200 Series 1200 Series

96-120 84-108 84-120

8-10 7-9 7-10

10.9 - 13.6 9.5 - 12.2 9.5 - 13.6

Bolt 1/4-20 (Case to Cover) Bolt 1/4-20 (Differential)

1300 Series 1300 Series

90-110 84-120

7.5-9.2 7-10

10.2 - 12.5 9.5 - 13.6

Bolt 1/4-20 (Case to Cover) Bolt 1/4-20 (Shift Lever Housing) Bolt 1/4-20 (Differential)

1400 Series 1400 Series 1400 Series

96-120 84-108 84-120

8-10 7-9 7-10

10.9 - 13.6 9.5 - 12.2 9.5 - 13.6

Bolt 1/4-20 (Case to Cover) Bolt 1/4-20 (Shift Lever Housing) Bolt 5/16-18 (Axle Support Housing) Bolt 1/4-20 (Differential) Bolt 3/8-16 (Axle Support Housing)

2300 Series 2300 Series 2300 Series 2300 Series 2300 Series

96-120 96-120 180-216 84-120 240-312

8-10 8-10 15-18 7-10 20-26

10.9 - 13.6 10.9 - 13.6 20.4 - 24.5 9.5 - 13.6 27.2 - 35.4

Bolt 1/4-20 (Case to Cover) Bolt 1/4-20 (Axle Support Housing) Bolt 1/4-20 (Differential)

2400 Series 2400 Series 2400 Series

96-120 96-120 84-120

8-10 8-10 7-10

10.9 - 13.6 10.9 - 13.6 9.5 - 13.6

Bolt 5-16/18 (Case to Cover) Bolt 3/8-16 (Differential) Bolt 1/2-13 (Axle Support Housing)

2500 Series 2500 & 2600 Series 2500 & 2600 Series

180-216 420-480 720-780

15-18 35-40 60-65

20.4 - 24.5 47.6 - 54.4 81.6 - 88.4

R.A.D. R.A.D.

20-24 90-110

1.6-2 7.5-9.2

2.2 - 2.7 10.2 - 12.5

Bolt 1/4-20 (Shift Lever Housing) Bolt 1/4-20 (Brake Disc) Bolt 1/4-20 (Case to Cover) Bolt 1/4-20 (Brake Disc)

Screws No. 10-24 (Cover) Bolts 1/4-20 (Retainer Cap)

NOTE: On all units containing two jam nuts, secure brake lever, hold the bottom nut and torque the top nut to 100 in. - lbs. (11.3 Nm). Differential Bolts 7 ft. - lbs. (9.5 Nm) “T” Drive Bolt 8-11 ft. - lbs. (10.9 - 15.0 Nm) “T” Drive Cover Screw 20-24 in. - lbs. (2.24 - 3.7 Nm) 8

RIGHT ANGLE DRIVES

100 SERIES

1100 SERIES A or B

300 SERIES 1200 SERIES

A

A A or B

700 SERIES

A or B

A 600 SERIES

A

A or B

A

810 SERIES 801 SERIES

2600 SERIES 2800 SERIES

A 910 SERIES

A

900 SERIES 920 SERIES 930 SERIES

A 1300 SERIES

A 2400 SERIES

A

915 SERIES

820 SERIES

A

2300 SERIES 2500 SERIES

A or B

A

A or B

MST

MOD 506 PEERLESS 1 275 1374

MODEL NUMBER REQUIRED FOR WARRANTY

Individual Serial Number Manufactured on the 275th Day Manufactured in 1991 MODEL NUMBER REQUIRED FOR WARRANTY

SPECIFICATION NUMBER REQUIRED FOR WARRANTY

VARIOUS STYLES OF IDENTIFICATION USED

SPECIFICATION NUMBER REQUIRED FOR WARRANTY

D.O.M. (DATE OF MANUFACTURE) ORIGINAL SERIAL NUMBER

D.O.M. (DATE OF MANUFACTURE) ORIGINAL SERIAL NUMBER MODEL NUMBER REQUIRED SPECIFICATION NUMBER FOR WARRANTY REQUIRED FOR WARRANTY

D.O.M. (DATE OF MANUFACTURE) ORIGINAL SERIAL NUMBER

Early Models were not identified with a model number on the unit. THE MODEL NUMBER WILL BE FOUND ON: A. Metal tag or decal attached to unit as illustrated. B. Stamped on unit as illustrated. Identification Number Locations

9

TROUBLE SHOOTING TABLE THE FIRST RULE IN TRANSAXLE TROUBLE SHOOTING IS TO ISOLATE THE PROBLEM TO THE TRANSAXLE. THE TECHNICIAN MUST CHECK FOR PROPER ADJUSTMENT OF THE BELTS, BRAKE, CLUTCH, SHIFTER AND LINKAGES. THE PULLEYS NEED TO BE CHECKED FOR SHEARED RETAINERS AND PROPER BELT DISENGAGEMENT. IF THE PROBLEM IS RELATED TO SHIFTING DIFFICULTIES, REMOVE THE DRIVE BELT AND RECHECK THE SHIFTING TO ASSURE THE PROBLEM IS NOT WITH THE ASSOCIATED EQUIPMENT. With the engine off, shift through the gear sequence. Only light resistance should be felt. If the unit shifts hard the problem is in the transaxle. Otherwise, check the following areas: the clutch adjustment, brake adjustment, belt release and the belt guide positioning. All current gear drive units are in-line shift and use shift keys to engage the desired gear to lock and then rotate with the shaft. This type of unit requires the transaxle or transmission to be in a no load condition (the clutch engaged) when gear selection occurs. Depressing the clutch pedal and therefore engaging the clutch, allows the unit to have the input and brake forces removed from the gears and shift keys, which allows the unit to shift freely and easily. Improper shifting (shifting while on an incline, shifting while towing any type of load, or shifting without clutch engagement) forces the shift keys to engage into a gear that is in a loaded condition. Improper shifting leads to premature wear and failure of the shift keys and drive gears and is considered abuse. Tecumseh's limited warranty covers only transaxle or transmission failures that are the result of a defect in the material or workmanship of the unit, not failures caused by normal wear or abuse by the operator. Some Original Equipment Manufacturers (OEM)'s use Tecumseh transaxles and transmissions in lawn tractors that do not use a foot operated clutch. These lawn tractors combine the clutch release mechanism with the hand operated gear shift lever. When the gear shift lever is moved through the shift gate from the gear engagement position toward the neutral position, the attached clutch linkage moves the idler pulley to release all input drive belt tension from the transaxle input pulley. With the drive belt tension released (clutch engaged), the transaxle is able to shift while on an incline or while towing any type of load. Remember, the Tecumseh Peerless limited warranty covers defects in the material or workmanship. It does not cover worn shift keys or gears caused by clutch/belt linkages not adjusted correctly.

Isolate Unit from Transaxle Use the following procedure to determine if a hard shifting condition is caused by the shifter/clutch linkage or an internal problem in the unit. 1. On level ground, start the engine and with engine running proceed to shift through the gears with the clutch pedal depressed (engaged). 2. If shifting is difficult, try shifting the transaxle with the engine shut off. 3. If the transaxle shifts freely through each gear with the engine shut off, the cause of the shifting problem is external to the unit. DO NOT REMOVE THE TRANSAXLE. 4. If shifting the unit with the engine shut off is difficult then disconnect the linkage from the shifter rod and shift through the gears with an open end wrench and compare the shift effort. 5. Check the clutch, shifter, and brake linkage for the proper adjustment by using the guidelines provided by the owner's manual or the Technician's Handbook for that specific equipment. 6. Hard shifting with the engine shut off can be caused by: a. bent or binding shift lever or linkage. b. shift linkage out of adjustment. c. corrosion in the transaxle or transmission. d. damaged shift keys, gears or shifter brake shaft. e. missing or misadjusted belt guides (see the (OEM's specs). NOTE DO NOT REMOVE TRANSAXLE UNTIL YOU HAVE CHECKED ITEMS 6A AND 6B. If the problem is internal, remove the transaxle from the equipment, disassemble and determine the cause.

10

TROUBLESHOOTING TABLE PROBLEM

REMEDY

UNIT CANNOT BE SHIFTED (OR DIFFICULT TO SHIFT) Gears installed incorrectly

Review positioning of gearing.

Forks and Rod assembly installed incorrectly

Remove assembly, recheck and correctly position parts.

Axle Housing installed incorrectly or not tightened correctly/ Axles cannot be turned (in the same direction) while unit is in Neutral

Seal retainers are not properly sealed. Tighten axle housing bolts.

Shifting lever improperly positioned

Determine if finger of shifting lever is correct for the unit and is correctly installed. Make sure shift lever housing has the required gasket.

Shifting keys broken or damaged

Replace keys and check unit for additional damage.

Shifting washers in backwards

Chamfered side on the inside diameter of the washer must face the tips of the keys.

Shifter/Brake shaft keyways damaged

Remove nicks and burrs from keyway.

Shift lever housing misaligned to case

Check if alignment marks on unit are correctly positioned. Also, determine if bend on shaft is in correct position.

Equipment clutch not engaging

Adjust clutch according to the operator manual of the equipment.

Shifter stop assembled backwards

Determine that the notch in the shifter STOP aligns with shifter forks in the NEUTRAL position.

Shift gear chamfer is positioned on the wrong side

Check that bevels on shifter gears are correct (fork flanges should be toward each other). On three-gear cluster models, the small gear and medium gear chamfers go down toward the larger gear. In-line models have the chamfer side of the gear facing toward the brake disc.

Improper fit of case to cover

Recheck positioning of thrust washers. A misplacement or omission of a washer can cause binding. Be sure that all tabs are down in the corresponding notches located in the case.

Dowel pins not installed

Check the exploded view for a correct assembly of parts.

Gears improperly installed

Check the exploded view for a correct assembly of parts.

Input shaft not properly installed

Input shaft spline must fit into the gear squarely and be tapped completely into the case.

Differential installed improperly

Re-check the positioning of the bolts in the differential. It must be opposite the output shaft gear (except 2400). In-line shift models need to have the differential gears centered so they will spin freely in the case with the cover removed.

Seal retainers improperly positioned

Check that seals are correctly installed.

11

TROUBLESHOOTING TABLE (Continued) PROBLEM

REMEDY

UNIT JUMPS OUT OF GEAR Gear teeth are worn beyond tolerances

Replace worn gears.

Spring in shifter fork weak or broken

Replace spring.

Attaching screws for shift lever and housing assembly not properly torqued

Torque screws to 10 ft. lbs. (13.6 Nm).

Shifter/Brake shaft improperly assembled

Reassemble properly per exploded view

Keys weak or worn, shift gears damaged

Replace keys/Shift gears.

Shift lever bent and hitting unit frame

Replace shift lever.

Shift rod grooves worn

Replace shift rods.

Shift rod of improper length or grooving installed

Check rod length. Replace with correct part.

Constant mesh gears improperly installed on counter shaft

Reposition gears.

AXLES CANNOT BE TURNED (IN THE SAME DIRECTION) WITH UNIT IN NEUTRAL Axle housing not installed (or not tightened)

Seal retainers are not properly seated. Tighten axle housing bolts.

Burrs on gearing

Remove gear and debur with a sharpening stone.

Broken shifter stop allowing unit to be shifted into two speeds at the same time

Replace snap rings on shift rod out of groove.

Thrust washers in wrong position

Recheck thrust washer and if wrong, reposition.

Bearings not pressed in deep enough

Use the proper bearing tool to seat the bearing.

UNIT DOES NOT DRIVE Differential bevel gears broken

Replace.

Three gear cluster countershaft key sheared in Model 600

Replace.

Stripped teeth on gears

Replace.

Keys sheared in drive pulleys

Replace.

Broken input gear

Replace.

Shift keys broken

Replace keys/check keyways and shift gears.

Reverse chain broken (reverse only unless chain becomes wedged)

Replace chain.

UNIT IS NOISY Gearing is overly noisy chatter, etc.

Check oil/grease level.

Metallic pieces or other foreign objects in unit

Remove bits of broken metal, loose washers, etc.

Worn gears

Remove and replace with new gears.

Worn bearings, mainly input shaft ball bearing

Replace the bearing in question/check the belt tension.

12

CHAPTER 2. 300 SERIES GENERAL INFORMATION

Basic Troubleshooting

The 301 series is a single speed transmission manufactured in various styles to meet customer application needs. The unit uses synthetic lubrication and is completely sealed for life and therefore not internally serviceable.

Should a drive problem exist, check the following:

Only the external parts listed below in the illustration are available from your normal source of supply.

4. Check for worn or glazed belt or damaged pulley

1. Cable adjustment 2. Belt tension and mechanism 3. Drive lever operation

5. Should the unit still not operate correctly replacement will be required.

Q R

Externally Serviceable Parts 1. Retaining Ring 2. Drive Pulley 3. Tension Spring 4. Retaining Ring or Push Nut 5. Drive Arm

U

S T

SERVICEABLE PARTS

ID LOCATION

13

CHAPTER 3. 600 SERIES TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury. GENERAL INFORMATION

INPUT SHAFT

COVER

CASE

LEFT AXLE

RIGHT AXLE

AXLE HOUSING CENTER PLATE DISC BRAKE

SHIFT LEVER HOUSING

IDENTIFICATION PLATE AXLE HOUSING

COVER

BRAKE SHAFT CASE

There are two types of 600 Series transaxles. One is the 600 standard series and the other is the 601-001, 002, 003, etc. slow speed series transaxle. This first section will deal with the standard 600 series. Please refer to the next section for information on 601 slow speed transaxle. The 600 Series transaxle has an aluminum case and cover. The input shaft is on the top of the case to receive vertical shaft power from the engine. Some 600 series transaxles are equipped with an optional disc brake. Due to the many variations of equipment braking systems, adjustments and repair to these components and linkages are not considered warranty.

2. After removing axle housings bench or clamp the transaxle in a soft jaw vise. Position the transaxle so that the socket head cap screws are facing up.

LEFT AXLE DOWEL PIN

AXLE HOUSING

TRANSAXLE DISASSEMBLY NEUTRAL POSITION

3. Remove the socket head cap screws holding the case and cover together. Drive out the dowel pins used for aligning the case and cover.

1. Clean the outside surface of the transaxle in an area away from where service will take place. Position the shift lever in the neutral position to ease disassembly of the transaxle. Remove the three screws holding the shift lever. Remove all keys from key ways, and remove all burrs and dirt from the shafts. On hardened shafts, use a stone or crocus cloth to remove any burrs and oxidation. All seals should be replaced whenever a shaft is pulled through a seal. Always use a new gasket whenever the gasket surfaces have been separated. 14

SHIFTER ASSEMBLY

SEAL PROTECTOR SHIFTER GEARS COVER

SHAFT SHIFTER RODS

REVERSE IDLER DIFFERENTIAL ASSEMBLY

CENTER PLATE ASSY.

INPUT SHAFT

4. Use a seal protector on the axle shaft and lift off the transaxle cover assembly. Because this seal is the single lip style, it may be reused if care is taken to see that it isn't cut or scratched.

THREE GEAR CLUSTER

7. Remove the complete shifter assembly by grasping the shifting gears, shaft and both shifter rods as a complete unit. NOTE Examine the assembly carefully; if no service is required, keep the assembly together as a unit. If service is necessary refer to Chapter 21 on shifting assemblies.

DIFFERENTIAL ASSEMBLY SCREW FASTENERS

INPUT SHAFT

5. To remove the differential assembly, it may be necessary to replace two or three screws that hold the center plate assembly down. Pull assembly straight up. If tight, tap on lower axle with a soft mallet. CAUTION: DO NOT USE STEEL HAMMER. Refer to the chapter on differential assembly service. Remove the gear on top of the shifter shaft.

BEVELED EDGE

8. Remove the reverse idler shaft, spacer and gear. 9. Remove the cluster gear sub assembly and thrust washer.

CENTER PLATE ASSEMBLY BEVELED EDGE THREE GEAR CLUSTER

SHIFTER ASSY.

6. After removing the center plate assembly screws, remove center plate and discard the gasket.

15

BEVEL LONGER KEYWAY

INPUT SHAFT

DIFFERENTIAL ASSEMBLY

SHORT KEYWAY

SEAL

SNAP RING

SMALL GEAR THRUST WASHER BEARING

BEVEL LARGE GEAR

MEDIUM GEAR SLEEVE

MEDIUM LONG SMALL SPACER GEAR GEAR

OLD STYLE

LARGE GEAR

SLEEVE BEVELED EDGE

SHORT

12. Remove the input shaft oil seal to allow access to the snap ring. Remove snap ring and input shaft will slide out. A removed seal must be replaced by a new seal. NOTE One model (612) has a sealed ball bearing instead of an oil seal. To remove this unit, remove snap ring inside the case and drive out. On model 612-A, remove the oil seal in the normal manner. SNAP RING RETAINER

10. Cluster Gear Sub-Assembly a. The cluster gear can be disassembled. All worn gears are replaceable if damaged or worn. It's preferred to use a press to drive the shaft out squarely. b. The small and medium gears' bevel faces down. There is no beveled edge on the large gear. The shorter spacer fits between the medium and the large gear.

SHIFTER STOP

SHIFTER RODS

BRAKE SHAFT

SHIFTER FORKS (IN NEUTRAL POSITION)

c. Key edge ends must align with shaft ends. SHIFTING ASSEMBLY THRUST BEARING

IDLER GEAR THRUST WASHERS

11. Remove the idler gear, thrust washers and thrust bearing.

16

The shifting assembly is usually removed from and installed into the transaxle as a unit. The assembly is removed and replaced by grasping the shifting rods firmly. This will cause the binding necessary to hold the assembly together. Before removal or installation of the shifting assembly, the notches in the shifter forks should be aligned with those on the shifter stop.

4. Insert the shifter assembly. Check that the shifter rods are seated properly.

SHIFTER STOP

SHIFTER RODS

BRAKE SHAFT

This alignment indicates the shifting assembly is in a neutral position. The shifter stop must be positioned so the notch aligns with the notches in the shifter forks. For service of the shifting assembly, refer to Chapter 9.

BEVELED EDGE

5. Install the reverse idler. Make sure the beveled edge is up. Place the spacer on top of the gear.

Transaxle Assembly CENTER PLATE ASSEMBLY

1. Install new seal, thrust washers, and bearing on input shaft. Note sequence, and install into case, using a seal protector. 2. Set case assembly open side up. Insert the idler gear assembly, thrust washers and bearing. Note sequence of washer and bearings from case; thick washer, thrust bearing thin washer, idler gear.

THREE GEAR CLUSTER

SHIFTER ASSY.

THRUST BEARING

IDLER GEAR THRUST WASHERS

6. Install the dowel pins to ease the cover installation. Then place a new gasket on the case and install the center plate. Position the differential assembly with the longer axle in the down position and be sure the gear on the shifter shaft is installed.

SEAL PROTECTOR

CAUTION Make sure the bearing and thrust washers remain in place while assembling the idler gear, shifter and brake shaft.

SHIFTER GEARS

DIFFERENTIAL ASSEMBLY

SHIFTER ASSEMBLY

CENTER PLATE ASSY. SCREW FASTENERS

SHAFT REVERSE IDLER

COVER

SHIFTER RODS

THREE GEAR CLUSTER

3. Insert the washer and then the three gear cluster assembly. Make sure the bevels on the two shifting gears are facing down.

7. Install the cover assembly and torque the cap screws to 7-9 ft. lbs. / 84-108 in. lbs. (9.5-12.2 Nm). 8. If the unit needs bearings or bushings installed, consult Chapter 22 for proper procedures.

17

9. Install the axle supports and fill with 24 oz. (710 ml) of S.A.E. 80W90 part number 730229B gear lube. Fill through the shifter housing.

NEUTRAL POSITION

10. Inspection Note: For a neutral position, shift notches in forks and notch in stop must be aligned and centrally located.

JAM NUTS

APPLY LUBRIPLATE

11. The brake lever type is determined by the original equipment manufacturer's selection of this option. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flat washer, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. To secure the brake lever, hold the bottom nut and torque top nut to 100 in. lbs. (10.2-11.3 Nm). The brake and linkages may vary. WARNING Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury.

18

601 SLOW SPEED TRANSAXLE GENERAL INFORMATION The 601 slow speed series uses the same case and cover as the 600 series so the appearance is the same. The following differences are as listed in three steps.

INPUT SHAFT

SEAL

SNAP RING IDLER GEAR THRUST WASHER BEARING THRUST WASHER

2. The input shaft only has one thrust washer instead of a thrust bearing and two thrust washers. THRUST WASHER

3. The 601 also has a different input shaft and bevel gear than the 600 transaxle.

1. Under the idler gear is one washer instead of a thrust bearing and two thrust washers. The 601 idler gear is different than the standard 600 Series.

600 SERIES BEARING TOOLS PART LOCATION Brake Shaft Axle *Input Shaft Center Plate Brake Shaft Differential Cluster Gear Idler Gear Axle Housing Reverse Idler

TOOL REMOVE & REPLACE 670210 670204 *670207A 670205 670213 670204 670204 670210 670204

BEARING SIZER (27 needles)

(30 needles)

*Bearing must be flush with top of case. Secure with Loctite.

19

600 SERIES TRANSAXLES

LUBRICATION Oil Bath 24 oz. (710 ml) S.A.E. E.P. 90 Oil Part No. 730229B To be filled through shifter lever opening.

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

20

CHAPTER 4. 700 SERIES TRANSMISSION IN-LINE SHIFT WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury. GENERAL INFORMATION The 700 Series in-line shift transmission is available in 2, 3, 4 or 5 speeds forward depending on equipment manufacturer’s specifications. The two speed version is not covered here but can be disassembled and reassembled using the same information for the 700 described in this section. I.D. TAG

NEUTRAL START PROVISION

DISASSEMBLY OF TRANSMISSION Clean outside surface of transmission. Position shift lever in neutral as indicated by the shift pattern. 1. If the unit has the OEM option of a neutral start switch, remove the switch. 2. Remove setscrew, spring and index ball from the transmission cover and six cap screws that fasten the cover to the case. 3. Remove cover. Remove shifter assembly (includes shafts, pins and fan from transmission by lifting shaft out of case. SETSCREW

COVER

INDEX BALL

CAP SCREWS CASE

4. Remove gear and shaft assemblies from the case lifting the two shaft assemblies together taking care not to separate the drive chain and sprocket relationship. Take note that the "fat" side of the sprockets must face the tips of the keys.

SHIFTER FAN OUTPUT SPROCKET SHIFT PATTERN OF ROTO-SHIFT

SPRING

SHIFTER ASSEMBLY SHIFTER ROD

DISC BRAKE

SHIFTER ROD

Optional features include right or left hand output and a disk brake, for either in-line or “H” pattern unit. NOTE Due to the many variations of equipment braking systems, adjustments and repair to these components and linkages are not considered warranty.

SHIFTER PINS

NEUTRAL START SWITCH

DISC BRAKE

OUTPUT SPROCKET

21

5. Remove the one-piece bevel spur combination gear and the remaining splined spur gears from the countershaft. 6. Remove from the shifter/brakeshaft the output sprocket, brake disc, all bushings, shifter spur gears, sprocket, collar, keys and chamfered washers.Note the inside chamfer on the shift washers face the tips of the keys to compress them and provide ease in shifting. Use approved safety procedures with equipment when handling shifter/brakeshaft parts. These parts have extremely sharp edges. Inadequate safety precautions could result in equipment damage and serious injury.

INSPECTION AND REPAIR Remove grease with rags and cleaning solvent and replace worn or damaged parts. ASSEMBLY OF THE 700 SERIES IN-LINE TRANSMISSION 1. Install and secure the input shaft and bevel gear in the case. Review paragraphs 7 & 8 and reverse the order.

CAUTION

"FAT SIDE" MUST FACE THE KEY TIPS REMOVE BEARING AND SPROCKET

COUNTERSHAFT BEVEL SPUR GEAR

THRUST WASHER CHAIN

SPUR GEARS BUSHING

SHOULDER THICKEST THRUST WASHER COLLAR

7. Remove the snap ring from the input shaft; remove bevel gear and pull shaft through case. 8. Input shaft needle bearings should be installed flush to .005" (.127 mm) below bearing bore surfaces from inside and outside the case. SNAP RING

NOTE All Needle bearings are lubricated with E.P. Grease. DO NOT USE BENTONITE GREASE on needle bearings. For maximum gear train life use Bentonite grease only on shafts and gears, Tecumseh part number 788067C. CHAMFERED SHIFT WASHERS. Many older models have a thrust washer with a 45o chamfer on the inside diameter. The latest style washer has a curved or rounded side. The purpose of the washers is to compress the shift keys as they slide into a gear. Therefore, the chamfered or rounded side of these washers must face the shoulder of the shaft or towards the tips of the shift keys. The washers are interchangeable. SHIFT GEARS. One side of the gear is flat and the other side is chamfered or recessed. The flat side of the gear is placed onto the shaft towards the shoulder of the shaft or towards the shift keys.

COLLAR KEY

BEVEL GEAR KEY THRUST WASHER

NEEDLE BEARINGS "O" RING THRUST WASHER SNAP RING INPUT SHAFT

22

SHOULDER

OUTPUT AND BRAKE SHAFT

SHOULDER

BEVEL SPUR GEAR

COUNTERSHAFT NEW STYLE

EARLY STYLE

THRUST WASHER (SEPARATES GEAR FROM BEARING) CUT OUT SIDE OF GEAR MUST FACE OUTBOARD END OF SHAFT

FLAT SIDE OF GEAR MUST FACE SHOULDER ON SHAFT

2. Starting from the output sprocket end on the shifter/ brake shaft, install a chamfered washer with the chamfer facing the shoulder on the shaft. With the output sprocket end down, place the shaft vertically in a vice with protective jaws and slide the collar and keys downward toward the shoulder and through the chamfered washer. Remember the "fat" side of the shift collar MUST face the key tips. Use work gloves as the keyways on the shifter/brake shaft are extremely sharp.

CHAIN SPROCKET BRAKE COLLAR KEY

SPUR GEARS

5. Install the chain over the two shafts making sure that the collars of both sprockets face inward toward the tips of the keys. 6. Install the appropriate protection washers on sprocket ends and bronze oil light bushings HUB MUST FACE BEVEL SPUR GEAR REMOVE BEARING AND SPROCKET

BUSHING

WASHER THRUST WASHER

BUSHING OUTPUT AND BRAKE SHAFT

SPUR GEARS

ANGLE SHAFT TOGETHER HERE

SHIFT SPUR GEARS

BUSHING

COUNTERSHAFT BEVEL SPUR GEAR

OUTPUT SPROCKET

3. Install the largest gear (first gear) with the chamfered end facing away from the key tips so that the flat side of the gear contacts the flat side of the chamfered washer. Remember the order as chamfer to chamfer and flat to flat when assembling the gears on the shifter brake/shaft. Install another chamfered washer noting that the chamfered side makes contact with the chamfered side of first gear. Install second gear and all remaining gears and washers the same way. The number of gears and/or spacers will be determined by the number of speeds requested by the OEM. 4. Install the splined bevel spur gear first (with the bevel facing away from the shifter rod) and remaining splined spur gears starting with the smallest to the largest on the counter shaft as shown.

CHAIN

SHOULDER COLLAR

THICKEST THRUST WASHER

7. Install shifter assembly (shaft, pins and fan) 12 oz. (355 ml) of Bentonite grease around the gearing, and reinstall the cover to the case. Torque cap screws 90-110 in. lbs. (10.2 - 12.5 Nm). SHIFTER ASSEMBLY SHIFTER FAN

SHIFTER ROD

SHIFTER PINS

23

8. For in-line transmissions, install the detent ball, spring and setscrew, in that order, into the cover. Slowly tighten the screw to flush, then one full turn below flush. The deeper you turn in the set screw the more tension will be on the shifter fan which will make the gear positions feel more deliberate to the operator. APPLY LUBRIPLATE

BRAKE BRACKET

9. Check for binding by turning the input shaft. Install transmission on equipment. Install brake and linkage, and adjust to disengage when clutch is engaged. Consult equipment Owner’s Manual. 10. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flatwasher, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. Install the brake assembly. The brake and linkages may vary. WARNING Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury.

24

700 SERIES TRANSMISSION

NOTE: These models can be built with brakes and sprockets either on right or left side.

LUBRICATION Permanent Lubrication 12 oz. (355 ml) Bentonite grease Part No. 788067C

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

25

700H SERIES TRANMISSIONS WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

SETSCREW

NEUTRAL START SWITCH

DISC BRAKE

If installed, remove the neutral start switch. This can be an option to the OEM. NOTE Due to the many variations of equipment braking systems, adjustments and repair to these components and linkages are not considered warranty. DISASSEMBLY OF THE TRANSMISSION 1. Clean the outside of the transmission and position the shift lever in the neutral position as indicated by the shift pattern. 2. Remove the shift lever by removing the four hex screws on the shift lever cover.

CAP SCREWS (6)

3. With a 3/32 inch Allen wrench, remove the set screw, spring and detent ball.

SHIFT PATTERN DISC BRAKE SHIFTER ROD

The "H' pattern transmission described here is a 4speed forward, 1 reverse unit. TORQUE SCREWS 70-90 IN. LBS (7.93-10.2 Nm)

TABS IN SLOTS

SHIFTER PLATES (2)

PLATE

The 700 "H" pattern transmission gear arrangement is similar to the in-line transmission except for the shift gate and an additional collar and spacer on the shifter/ brake shaft. The countershaft also has an additional spacer.

4. Remove the six cap screws that fasten the cover to the case; then remove the cover. COUNTERSHAFT HUB MUST FACE BEVEL SPUR GEAR BEVEL SPUR GEAR REMOVE BEARING AND SPROCKET

THRUST WASHER

SPUR GEARS BUSHING

ANGLE SHAFT TOGETHER HERE

CHAIN

SHOULDER COLLAR

THICKEST THRUST WASHER

5. Remove the gear shaft assemblies from the case half of the transmission by lifting the two shafts out of the bearing supports taking care not to disturb the drive chain relationship of the sprockets. 6. Angle the chain and sprocket ends of shaft toward each other, removing the bearing and sprocket from the countershaft. Note the collar on the sprocket faces the bevel spur gear. Remove the chain. BEVEL SPUR GEAR

SPACER

Disassembly of the 700 series “H” shift pattern includes a spacer. 26

BRAKE DISC

OUTPUT SPROCKET

CHAIN SPROCKET KEY COLLAR

SHOULDER

450 CHAMFER

THRUST WASHER (SEPARATES GEAR FROM BEARING)

BUSHING BUSHING

OUTPUT AND BRAKE SHAFT

SNAP RING FLAT SIDE OF GEAR MUST FACE SHOULDER ON SHAFT

Disassembly of the 700 series "H" shift pattern includes a second collar and a spacer. SNAP RING

BEVEL GEAR THRUST WASHER

INSTALL BEARINGS FLUSH TO .005" (.127mm) BELOW CASE SURFACE

"O" RING

NEEDLE BEARINGS

SNAP RING

CUT OUT SIDE OF GEAR MUST FACE OUTBOARD END OF SHAFT

NOTE The thrust washer on the brake disc end of the shifter/ brake shaft does not have a chamfer on the inside diameter and must be positioned as shown above. It is thicker than the other thrust washers separating the gear works from the bearings. BRAKE DISC

CHAIN SPROCKET COLLAR

THRUST WASHER

KEY

OUTPUT SPROCKET

INPUT SHAFT

Input shaft removal is the same for both the 700 series in-line and “H” shift pattern transmissions. 7. Remove the snap ring and bevel gear from the input shaft and pull the shaft through the case. 8. The input shaft needle bearings should be installed flush or no more than .005" (.127 mm) below the bearing bore surface from inside and outside the case. INSPECTION AND REPAIR Examine all parts after removing grease with rags and cleaning solvent to determine which parts need replacement.

OUTPUT AND BRAKE SHAFT

BUSHING

BUSHING

1. The first, second and third gears have to be forced over the keys when assembling. Remember to place the spacer in the 4th gear position. BEVEL SPUR GEAR

ASSEMBLY OF 700H SERIES TRANSMISSION KEY

KEY

OUTPUT AND BRAKE SHAFT

Assembly is the same as the 700 series in-line transmission except for an additional collar and spacer.

SPACER

2. Assemble the countershaft and gears as shown above remembering the spacer is in the 4th gear position. 27

COLLAR MUST FACE BEVEL SPUR GEAR COUNTERSHAFT REMOVE BEARING AND SPROCKET

BEVEL SPUR GEAR SPACER

THRUST WASHER

TORQUE SCREWS 70-90 IN. LBS (7.93-10.2 Nm)

TABS IN SLOTS

BUSHING

THRUST WASHER BUSHING TABS

SHIFTER PLATES (2)

ANGLE SHAFT TOGETHER HERE

BUSHING TABS

PLATE THRUST WASHER SHOULDER CHAIN

SPACER

THRUST WASHER

3. With the collar on the countershaft sprocket facing the bevel spur gear, install sprocket onto the serration and install chain. Install all four (4) thrust washers. SPACER

NOTCHES NOTCHES

6. For in-line transmissions, install the detent ball, spring, and setscrew, in that order, into the cover and slowly tighten the screw up to two turns below flush. Depending on personal preference. The deeper you turn in the set screw the more tension will be on the shifter fan which will make the gear positions feel more deliberate to the operator. 7. Check for binding by turning the input shaft. Install the transmission on the equipment. Install the brake and linkage and adjust the clutch according to the equipment Owner’s Manual. APPLY LUBRIPLATE

BRAKE BRACKET

SPACER

4. Install the bronze bushings, disc and sprocket. Install the shaft assemblies into the case pressing the bushing tabs into the notches in the case. Be sure bushings tabs are seated in transmission case, or the cover won't sit squarely on the case.

CAUTION

SPACER

NOTCHES NOTCHES

8. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flatwasher, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. The brake and linkages may vary. Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury. WARNING

SPACER

5. Install the shifter assembly, 12 oz. (355 ml) of Bentonite grease around the gearing, installing the cover on the case. Torque the cover fasteners 90110 in. lbs. (10.2-12.5 Nm). 28

700H SERIES TRANSMISSION

LUBRICATION Permanent Lubrication 12 oz. (355 ml) Bentonite grease Part No. 788067C

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

29

CHAPTER 5. 800/801 SERIES TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury.

INPUT SHAFT

SPRING

WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

SET INDEX FAN SHAFT SCREW BALL ROD

IDENTIFICATION TAG

IDENTIFICATION The unit model number will be found on a metal tag at either of the two locations. DISASSEMBLY 1. Clean outside surface of the transaxle. 2. Position shift lever in the neutral position as indicated by the shift pattern.

GENERAL INFORMATION NOTE Due to the many variations of equipment braking systems, adjustments and repair to these components and linkages are not considered warranty. The brake may be either a left-hand or right-hand per the O.E.M. option.

3. If installed, (O.E.M. option) remove neutral start switch. 4. Remove the allenhead setscrew, the detent ball and spring . SHIFT ROD ALLENHEAD SCREW

NEUTRAL START SWITCH (OPTIONAL)

NEUTRAL START SWITCH (OPTIONAL)

DISC BRAKE (LEFT OR RIGHT HAND OPTIONAL) BRAKE BRACKET SCREWS

SETSCREW

COVER CASE HEX SCREWS (17)

INPUT (O.E.M. OPTION)

The 800/801 series transaxle is basically a combination of the 700 series transmission with a 600 series transaxle differential. The position of the input shaft varies with a particular model. Because of the option of the input shaft and gear positioning on either side of the bevel gear, the axle output will vary, which allows the O.E.M. the ability to rotate and reverse mount the transaxle. The model described in this section is a five speed forward, single reverse. The input shaft for this model is located to the left of the bevel gear.

30

NOTE Prior to removing the cover and the two gear shaft assemblies from the case, remove the square cut "O" ring from the top of the shifter rod. 5. Remove the case fasteners and push the shift rod through the cover. The shifting assembly may temporarily remain in the case. 6. Remove the two brake bracket screws, and remove the brake assembly.

NOTE Before disassembly, observe how the “V” notches on the flanged bushings fit into the corresponding recess in the case.

SHIFTER/BRAKE SHAFT

8. Remove the needle bearing (closed end) flat washers (2), output gear and output pinion, and 3 square cut seals from the countershaft. (2 seals in the output pinion 1 in the needle bearing cap). The "O" rings on the countershaft are larger than those on brake the shaft ends. Always replace with new seals whenever service is performed.

CASE HALF SHIFTER FAN

OIL SEAL

FLANGED BUSHING

OIL SEAL

SHIFTER/BRAKE SHAFT

SPUR GEAR

FLANGED BUSHING

SQUARE CUT "O" RING

SPROCKET COLLAR

THRUST WASHER

BEARING

FLANGED BUSHING DIFFERENTIAL

FLANGED COUNTERBUSHING SHAFT

SHIFT WASHER

BEARING RETAINER ASSEMBLY SPACER

NOTE The square cut black rubber “O” rings on the shifter brake shaft which retain the Bentonite grease in the case. 7. Remove gear and shaft assemblies from case half by lifting the two shafts out of the bearing supports taking care not to disturb drive chain relationship with the hubs on the sprockets.

COUNTERSHAFT

SQUARE CUT "O" RING

SPROCKET COLLAR

9. Angle the shifter/break shaft and countershaft chain sprocket ends toward each other. Note the collar on the sprockets face the bevel gear. Next remove the chain.

NOTE Remove the Bentonite grease from all parts and case halves as they are removed.

FLANGED BUSHING

SPUR GEARS SPLINE FOR CHAIN SPROCKET GEAR

SHIFTER GEARS

THRUST WASHER SPUR GEAR

SHIFTER/BRAKE SHAFT

FLANGED BUSHING

COUNTERSHAFT SPROCKET

NEEDLE BEARING (CLOSED END) OR BALL BEARING

SPACER

KEY COLLAR

THRUST WASHER

THRUST WASHER FLANGED BUSHING

10. Remove the sprocket, bevel gear, spur gears, thrust washer, and flanged bushing. The spur gears are splined to the countershaft.

OUTPUT GEAR OUTPUT FLAT WASHER (SQUARE PINION CUT SEAL IN EACH END FLAT WASHER OF OUTPUT PINION)

BEVEL GEAR

FLANGED SPUR BUSHING GEARS

31

FLANGED BUSHING SPROCKET FLANGED BUSHING

SPLINE FOR DISC BRAKE

SHIFTER/BRAKE SHAFT

SQUARE CUT "O" RING

OLD STYLE

SQUARE CUT "O" RING

"A"

"C"

NEW STYLE "D" SQUARE KEY CUT "O" "V" NOTCH SHIFT RING COLLAR THRUST WASHER SHIFT WASHER

"V" NOTCH

THRUST WASHER (NO CHAMFER)

"B" HEAVY DUTY SEALED BALL BEARING

SEAL

SHIFTER GEARS

11. From the shifter/brake shaft remove the square cut seals (2), flanged bushings (2), thrust washers (2) on the shaft ends, spur gear, spacer, sprocket, shift collar with keys, thrust washers and the shifter gears. FLANGED BUSHING

SEAL

The 800 Series has used four styles of bearings on the axles. The earliest style "A" was a smaller caged needle bearimg. Style “B” must have the seal to the outside of the bearing. When bearing style “C” is used, a square cut “O” ring must be used on each side of the bearing. Bearing style “D” is a sealed ball bearing used in heavy duty applications. Styles “B”, “C” and “D” are interchangeable. All needle bearings must be repacked with grease. Never use Bentonite grease in ball or needle bearings; use wheel bearing grease.

BEARING BEARING NEEDLE BEARING FLUSH WITH HOUSING SEAL THRUST WASHER

DIFFERENTIAL

FLANGED BUSHING

12. Remove the differential from the case. Remove the (2) seals, needle bearings or ball bearings (2).

SQUARE CUT "O" RING

BEVEL GEAR RETAINING RING

INPUT SHAFT RETAINING RING WASHER NEEDLE BEARINGS .135" (3.43 mm) .150” (3.82 mm) THRUST WASHER

13. To disassemble the input shaft remove the retaining ring on the bevel gear side from the input shaft; then remove the bevel gear and pull the shaft through the case. The square cut “O” ring must be replaced if removed. Tool Part No. 670251 is used for removal and installation of needle bearings for the input shaft. The needle bearing on the inboard side is installed .135" - .150” (3.43 - 3.82 mm) below flush.

32

ASSEMBLY 1. Apply E. P. grease between bearings and install and secure the input shaft and bevel gear in the cover. For maximum gear train life use only Bentonite grease on all shafts and gears, Tecumseh part number 788067C. COLLAR SHOULDER

KEY

KEY

DISC BRAKE SPLINE

THRUST WASHERS. A running change has been made to the shift washers. Many models have used the thrust washer with a 45o chamfer on the inside diameter. The latest style washer has a curved or rounded side. The purpose of both washers is to compress the shift keys as they slide into the gears. Therefore, the chamfered or rounded side of these washers must face the shoulder of the shaft or towards the shift keys. The washers are interchangeable. SHIFTING GEARS. The two sides of the shift gears are different. One side is flat and the other side is recessed to accept shift washers. The flat side of the gear is placed onto the shaft towards the shoulder of the shaft or towards the shift keys.

SHIFTER/BRAKE SHAFT

2. Grease the keyways and slide the shift keys and collar onto the shifter/brakeshaft. The thick side of the shift collar MUST face the shoulder (brake end) on the shaft. Service replacement shifter/brake shafts will come with four keyways on the shaft instead of two. NOTE When repairing the unit use, the same number of keys that were used originally. SHOULDER

RECESS

EARLY STYLE

SHIFT WASHER

FLAT SIDE OF GEAR MUST FACE SHOULDER ON SHAFT

NEW STYLE

THRUST WASHER (SEPARATES GEAR FROM BEARING) CUT OUT SIDE OF GEAR MUST FACE OUTBOARD END OF SHAFT

3. Install the thrust washers and shifting gears onto the shifter/brake shaft. The number of gears and/ or spacers will be determined by the number of speeds in the transmission ordered by the O.E.M.

33

FLANGED BUSHING

FLANGED BUSHING SPROCKET SHIFTER/BRAKE SHAFT

SQUARE KEY CUT "O" "V" NOTCH SHIFT RING THRUST COLLAR WASHER SHIFT WASHER

SPLINE FOR DISC BRAKE

"V" NOTCH

SQUARE CUT "O" RING

FLANGED BUSHING

SHIFTER/BRAKE SHAFT

SPUR GEAR

FLANGED SQUARE CUT BUSHING "O" RING

SPROCKET COLLAR

THRUST WASHER (NO CHAMFER)

THRUST WASHER

SHIFT WASHER

SHIFTER GEARS SPACER

NOTE The large thrust washer on the shift gear end of the shifter/brake shaft does not have a chamfer on the inside diameter. 4. Reassemble the shifter/brake shaft by installing the sprocket and chain, spacer, spur gears, and thrust washers. Be sure the collar on the sprocket faces inward toward the shift collar or toward the brake end of the shaft. Install the appropriate thrust washers and the bronze oil light bushings on both ends of the shifter/brake shaft; then install the square cut “O” ring on the brake end of the shaft. Opposite the brake end, there is a steel spacer disk; there is not an "O" ring on that end.

COUNTERSHAFT

SQUARE CUT "O" RING

SPROCKET COLLAR

6. With the ends of the countershaft and shifter/brake shaft angled together, install the countershaft sprocket and chain on the countershaft. SQUARE CUT "O" RING

THICKER FLAT WASHER

LARGE WASHER SPUR GEARS SPLINE FOR CHAIN SPROCKET GEAR OUTPUT GEAR COAT AREA WITH GREASE

COUNTERSHAFT

OUTPUT PINION .135" -.150" (3.43-3.81 mm) BOTH ENDS

SPROCKET BEVEL GEAR

THRUST WASHER FLANGED BUSHING

NOTE Depending on the model specification, the bevel gear may be installed one of two ways. For description purposes, in this section, the model used has the bevel on the gear facing inward. 5. On the countershaft, install the bevel gear and the spur gears starting with the smallest to largest, (opposite the shifter/brake shaft spur gear arrangement). Place a thrust washer and bronze oil light bushing on the spur gear end of the countershaft. Note that the “V” notch on the bushing fits into the recess “V” in the case.

34

7. For correct positioning of the needle bearings use the removal/installation tool, Tecumseh part # 670252. Fill the area between the needle bearings with axle grease before installing on the countershaft.

FLANGED BUSHING

SHIFTER GEARS

THRUST WASHER SPUR GEAR

NEEDLE BEARING (CLOSED END) OR BALL BEARING

SPACER

SHIFTER/BRAKE SHAFT

"V" NOTCH SQUARE CUT

INPUT SHAFT

FLANGED BUSHING "O" RING

IDENTIFICATION TAG

SPUR GEARS

FLANGED BUSHING

8. Install the flat washer to protect the turning sprocket from the square cut seal which fits into the recessed end of the output pinion gear. Install a square cut seal on the other end of the output pinion and the output gear. The large protective thrust washer keeps these in position. There is another square cut rubber seal that fits into the recessed end of the needle bearing sleeve assembly (closed end). Place it on the end of the countershaft and the two shafts are complete and ready to install into the case.

OIL SEAL

FAN SHAFT ROD

SPRING

OUTPUT GEAR

SHIFTER/BRAKE SHAFT

INDEX BALL

THRUST WASHER

KEY COLLAR

FLAT WASHER OUTPUT (SQUARE CUT SEAL PINION IN EACH END OF FLAT WASHER OUTPUT PINION)

SET SCREW

NOTE On reassembly, use either gasket eliminator Loctite 515 (part number 510334) or silicone RTV Loctite 598 (part number 788093). 11. Install the shifter fan detent ball, spring and setscrew in that order, into the cover, and slowly tighten the screw one turn below flush. If unit contained a neutral start switch, reinstall it. Check for binding by turning the input shaft. APPLY LUBRIPLATE

CASE HALF SHIFTER FAN

BRAKE BRACKET

OIL SEAL

BEARING

FLANGED BUSHING

BEARING COUNTER- RETAINER DIFFERENTIAL FLANGED ASSEMBLY SHAFT BUSHING

9. DIFFERENTIAL ASSEMBLY Install the flanged bushings (2), flat washers, needle bearings or ball bearings (2), and oil seals (2), with seal grooves facing out. For teardown and reassembly of the differential, see Chapter 18 on differentials. Install the differential in the case. 10. Install the shifter assembly, and pack 30 oz.(887ml) (36 oz. [1065 ml] 801 Series) of Bentonite grease around the bearings and gearing, then reinstall cover on the case. Torque cap screws 90-100 inch pounds (10.2-11.3 Nm).

12. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flat washer, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. Install brake assembly. Install the transmission on the equipment. Adjust the brake linkage to disengage when the clutch is engaged. The brake and linkages may vary. Consult the equipment owner's manual. Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury. WARNING

35

800/801 SERIES TRANSAXLES

LUBRICATION Permanent Lubrication 30 oz. (887 ml) for 800 Series 36 oz. (1065 ml) for 801 Series Bentonite grease Part No. 788067C

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

36

820 SERIES TRANSMISSIONS It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING

When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING

WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

3. Remove cover. Remove shifter assembly (includes shift rod and shifter fan) from transmission by lifting shaft out of case. 4. Remove bearing cap, differential, shift fan, output shaft assembly and then both the shifter/brake shaft and countershaft simultaneously. Take note that the "fat" side of the sprockets must face the tips of the keys or the brake side. 5. OUTPUT PINION AND SHAFT. Remove sleeved needle bearings. Remove the large thrust washers and large output gear. The output pinion gear is machined directly onto the output shaft in most models. There are models in which the output shaft is splined to accept a splined output pinion gear and a splined output gear. SHIFT FAN

BEARING CAP

OUTPUT SHAFT ASSEMBLY

SHIFTER/BRAKE SHAFT ASSEMBLY

GENERAL

COUNTERSHAFT ASSEMBLY

The 820 series is similar to the 920 series transaxle in basic operation. It has up to 6 speeds forward and one reverse. The 820 series is a heavy duty unit which is suited for ground engaging attachments. The 820 features ball bearings, needle bearings and steel cut gears throughout. NOTE

SLEEVED NEEDLE BEARINGS

Due to the many variations of equipment braking systems, adjustments and repair to these components and linkages are not considered warranty. INPUT SHAFT

DIFFERENTIAL BEARING SLEEVE

"O" RING OUTPUT GEAR

NEEDLE BEARING

OPTIONAL INPUT SHIFT ROD LOCATION INDEX BALL, SPRING AND SET SCREW

COVER/CASE HEX SCREWS (17)

NEEDLE BEARING

THRUST WASHER

"O" RING OUTPUT BEARING PINION THRUST WASHER SLEEVE

IDENTIFICATION TAG NEUTRAL START SWITCH LOCATION (OPTIONAL)

BRAKE BRACKET SCREWS (BRAKE CAN BE ON RIGHT OR ON LEFT SIDE)

DISASSEMBLY OF TRANSMISSION Clean outside surface of transmission. Position shift lever in neutral as indicated by the shift pattern. 1. The unit may have the OEM option of a neutral start switch, remove the switch. 2. Remove setscrew, spring and index ball from the transmission cover and six cap screws that fasten the cover to the case. 37

6. COUNTERSHAFT AND SHIFTER/BRAKE SHAFT As these assemblies are taken apart, lay the parts out in a systematic order. This will help to make reassembly easier and inspection of all parts possible. Clean each part of grease as the parts are laid out. SHIFTER/BRAKE SHAFT ASSEMBLY

REASSEMBLY NOTE Do not apply bentonite grease to needle bearings; use only EP grease. For maximum gear train life use only Bentonite grease on all shafts and gears, Tecumseh part number 788067C. 1. Install the input shaft, and all the associated parts in the order shown on the input shaft breakdown. 2. Grease all four keyways, insert keys into collar and keyways and slide onto the shifter/brake shaft. SHIFTER/BRAKE SHAFT

COUNTERSHAFT ASSEMBLY SHIFT COLLAR

7. INPUT SHAFT The input shaft can also be removed and inspected or serviced. Remove the snap ring on the bevel gear and pull the shaft through the cover. The seal must be replaced if the shaft is removed.

SNAP RING BALL BEARING

INPUT SHAFT

SHIFT KEYS (4)

3. It is easier to assemble this transaxle if the countershaft and the shifter/brake shaft are assembled at the same time. Start by placing the reverse chain over the reverse sprockets. Make sure the collars on the sprockets are on the same side of the chain, facing the brake side and toward the tips of the keys. Place the neutral spacers onto the shifter/brake shaft with the larger inner diameter sides facing together. Position the spacer with the largest inner diameter radius toward the shift keys and brake end of the shifter/brake shaft. Push the shifting keys through the reverse sprocket and the first neutral spacer, pull the neutral spacers and the reverse sprocket up against the shoulder of the shifter/brake shaft.

NEEDLE BEARING LARGER RADIUS SPACE TOWARD SHIFT KEYS

SEAL

LARGE INNER DIAMETERS FACE EACH OTHER

THRUST WASHER (Large) "O" RING

NEUTRAL SPACERS

THRUST WASHER (Small) THRUST BEARING THRUST WASHER GREASE THESE AREAS

CUPPED THRUST WASHER INPUT PINION SNAP RING

8. DIFFERENTIAL Refer to Chapter 18 on differentials for service. Should disassembly of the differential be necessary, 2 oz. (.59 ml) of bentonite grease should be placed around the gears on reassembly. 38

REVERSE CHAIN SPROCKET COLLARS

4. Insert the countershaft into the smaller reverse sprocket. Then install the large bevel gear, with the bevel facing away from the reverse sprocket. Place thin thrust washer on the countershaft next to the bevel gear.

NOTE It is not only important that gears match up diameterwise, but must match up according to thickness. As all the gears are placed back into the assembly, pack each with bentonite grease.

COUNTERSHAFT THRUST WASHERS LARGE INPUT BEVEL GEAR

BEARING ASSEMBLY

THRUST WASHER

NOTE

THRUST WASHERS

Depending on model, the bevel may be installed one of two ways. For description purposes in this section, the model used has the bevel side of the large bevel gear facing away from the reverse sprocket; in other models the bevel may face toward the reverse sprocket. In either case there is a thrust washer placed on the counter shaft after the large bevel gear. Some models may also have the smallest spur gear machined onto the countershaft. In this case the large bevel gear must be placed onto the countershaft prior to inserting shaft into the reverse sprocket. These models will not have a thrust washer placed next to the large bevel gear. SHIFT GEARS

SHIFT WASHERS

SLEEVE NEEDLE BEARING "O" RING ASSEMBLY THRUST BEARING

SPACER WASHER

6. In the model pictured above, a thrust washer, thrust bearing, thrust washer and sleeved needle bearing with an “O” ring are placed on the countershaft next to the reverse sprocket. Place a spacer washer and sleeved needle bearing with an “O” ring next to largest spur gear. Install the sleeved needle bearing with the step facing outward and the wider portion of the bearing sleeve toward the cover. This will be true for all future sleeve bearing installations. NOTE On models with the large bevel gear facing in the opposite direction, the two thrust washers and the thrust bearing will be placed next to the largest spur gear, and the spacer washer will be placed next to the reverse sprocket. See the diagram at the top of the next page. THRUST WASHER

THRUST WASHER

SPUR GEARS SHIFTING WASHER

CUT OUT SIDE

FLAT SIDE

5. Build the gears on the countershaft and shifter/ brake shaft alternately, meshing each gear with it’s mating gear on the other shaft. The first gear on the shifter/brake shaft is the largest of the shift gears. Place this gear next to the neutral spacer with the flat side of the gear next to the spacer. Place a shift washer onto the shifter/brake shaft with the rounded edge towards the shift keys. Continue this procedure until all the gears on both shafts have been added.

SPUR GEAR BEARING ASSEMBLY BEARING ASSEMBLY

7. Place a large thrust washer next to the last shifting gear (this may be a step washer on some models) then a sleeved needle bearing with an “O” ring. Place the spur gear, small thrust washer and sleeved needle bearing with “O” rings on the opposite end of the shifter/brake shaft. 39

NOTE Dependent on whether the brake is on the right or the left, will determine which end uses a capped sleeved needle bearing. 8. Place the output gear on the stepped end of the output pinion. Place thrust washers on each end and then the large sleeved needle bearings with "O" rings. The "O" rings protect the axle/wheel bearing grease in the sleeved needle bearing from the Bentonite grease which lubricates the spur gears. Install the three shaft assemblies into the case.

BEARING SLEEVE

11. Guide cover over shift rod and position onto case. Torque cover screws 180-216 inch pounds (20.424.5 Nm). Replace the detent ball, spring, and set screw. Turn set screw one (1) turn below flush. Install the neutral start switch if applicable. Check for binding by turning the input shaft. SHIFT ROD

INDEX SET SCREW

NEEDLE BEARING

"O" RING OUTPUT GEAR

NEUTRAL START SWITCH

NEEDLE BEARING

THRUST WASHER

"O" RING OUTPUT BEARING THRUST PINION WASHER SLEEVE APPLY LUBRIPLATE

9. Insert differential into the case; position the caged ball bearings on the axle ends into the recessed areas of the case. Place the bearing cap over the sleeved needle bearing of the countershaft and torque the bolts 90-100 inch pounds (10.2-11.3 Nm). Install shifter fan and pack the transaxle with remaining bentonite grease. (36 oz. / 1065 ml total)

BRAKE BRACKET

10. Clean mating surfaces of the case and cover; place a continuous thin bead of sealant all around the seam. Use Loctite Gasket Eliminator #515, Tecumseh Part No. 510334 or the Loctite Silicone RTV 598, Tecumseh Part No. 788093. SHIFTER ASSEMBLY

BEARING CAP

BALL BEARING

12. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flatwasher, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. Install brake assembly. Install the transmission on the equipment. Adjust the brake linkage to disengage when the clutch is engaged. The brake and linkages may vary. Consult the equipment owner's manual.

BALL BEARING DIFFERENTIAL

40

WARNING Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury.

820 SERIES TRANSMISSION

LUBRICATION Permanent Lubrication 36 oz. (1065 ml) of Bentonite grease Part No. 788067B (No acceptable substitute)

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

41

CHAPTER 6. 900 SERIES TRANSAXLES It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING

When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING

WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

DISASSEMBLY OF TRANSAXLE Clean outside surface of transaxle. Position shift lever in neutral as indicated by the shift pattern. 1. The unit may have the OEM option of a neutral start switch, remove the switch. 2. Remove Allen head setscrew, spring and detent ball from the transmission cover and six cap screws that fasten the cover to the case. 3. Remove cover. Remove shifter assembly (includes shift rod, and shifter fan from transaxle by lifting shaft out of case. 4. Remove two brake bracket screws and remove brake assembly. NOTE Remove grease from the unit as parts are removed. It will be difficult to keep parts from falling off the assemblies. Note position of parts before removal.

NOTE Due to the many variations of equipment braking systems, adjustments and repair to these components and linkages are not considered warranty.

SHIFT FAN ASSY.

5. Remove the gear and shaft assemblies from the case half. NOTE GENERAL The 900 series is similar to the 800 series transaxle but has only up to 4 speed offerings forward and 1 reverse. The differential utilizes bearing blocks and is retained by the case and cover. This unit contains an aluminum tag at location A or B, showing the model number. COVER CASE HEX SCREWS

Before disassembly, observe how the bushing tabs on the flange bushings fit into recess “V” notches of the case. The cover will rock back and forth and not rest tightly on the case if these bushing tabs are not pressed down in the "V" notches. COUNTERSHAFT

OUTPUT SHAFT

INPUT SHIFT ROD SHAFT "V" NOTCHES A B ID TAG

SHIFTER/BRAKE SHAFT

6. To disassemble the countershaft, output pinion and shaft assembly, simply pull apart. 42

COUNTERSHAFT

10. DIFFERENTIAL

7. Remove the two (2) thrust washers, sprocket, bevel gear, spur gears and flanged bushing. The sprocket, bevel gear and spur gears are splined to the countershaft. COUNTERSHAFT

BUSHING

Remove the top bearing block on the bull gear of the differential. Remove the bull gear, bevel pinion gears with center shaft, and the axles. Grasp the axle bevel gears between your thumb and fingers; hold together while lifting differential from case. Remove bottom bearing block from case. BEARING BLOCKS BEVEL GEAR

AXLE

BEVEL PINIONS

2 SNAP RINGS RING GEAR WASHER

11. INPUT SHAFT OUTPUT GEAR PINION GEAR

BUSHING BUSHING

WASHER

SHAFT

Remove retaining ring on bevel gear end from the input shaft, remove bevel gear and pull shaft through case. The square cut “O” ring must be replaced, if removed.

NEEDLE BEARING FLUSH WITH HOUSING

WASHER

SQUARE CUT "O" RING

8. OUTPUT PINION AND SHAFT Remove the large brass bushing, large washer, large output gear, washer and bushing. The shaft and output pinion gear come as an assembly.

BEVEL GEAR RETAINING RING

9. SHIFTER SHAFT Remove the square cut “O” ring (1) and flanged bushings (2), thrust washers (2) on shaft ends, shift collar with keys, sprocket, spacer, shifter gears and thrust washers.

INPUT SHAFT RETAINING RING WASHER NEEDLE BEARINGS .135" (3.43 mm) .150" (3.81 mm) THRUST WASHER

Tool part no. 670251 is used for removal and installation of needle bearings for the input shaft. The needle bearing on inboard side is installed .135"-.150” (3.43-3.81 mm) below flush.

BUSHING KEY

SHIFTER GEAR

NEUTRAL SPACER

BUSHING

SHIFTER COLLAR

43

REASSEMBLY 1. Apply E.P. grease between bearings in the cover and install the input shaft, square cut seal, thrust washers, bevel gear and snap ring.

SHIFT WASHERS

NOTE Needle bearings are lubricated with E.P. grease. Do not use bentonite on any needle bearing. For maximum gear train life use bentonite grease on shifter/brake shaft. SHIFTING GEARS

2. Grease both keyways and slide keys and collar on the shifter/brake shaft. NOTE When reassembling the 900 series it is easier to assemble the shifter/brake shaft and the countershaft at the same time. REVERSE SPROCKET COLLAR "O" RING "O" RING

CUT OUT SIDE OF GEAR MUST FACE OUTBOARD END OF SHAFT

FLAT SIDE OF GEAR MUST FACE SHOULDER ON SHAFT

5. Place the largest of the shifting gears with the flat side of the gear next to the neutral spacer. Then place a shifting washer with the chamfer on the inside diameter of the washer next to the gear. The chamfer or rounded side must face towards the shifting keys. NOTE As all the gears are placed back into the assembly, each should be packed with bentonite grease. LARGE BUSHING

NEUTRAL SPACER

3. Place the reverse chain on the reverse sprockets. Make sure the collars on the sprockets are on the same side of the chain, facing the brake side, and toward the tips of the keys. Slide the keys through the sprocket and install the neutral spacer over the ends of the shifting keys and pull them back until the sprocket touches the shoulder of the shaft. WASHER THRUST WASHER

THRUST WASHER

6. Next place a thrust washer on each end of the countershaft and a bushing on the end of the shaft with the largest spur gear. 7. On the shifter/brake shaft place a large thrust washer next to the smallest shifting gear, next the bronze bushing and then an “O” ring. NOTE

SPROCKET

4. Insert the splined countershaft into the smaller reverse sprocket. Then place the large beveled gear on the countershaft with the beveled side of the gear towards the reverse sprocket. If the 900 series is a 1, 2, or 3 speed forward unit, place a washer over the shaft and next to the backside of the large bevel gear. If the unit is a speed forward there will not be a washer on the inside diameter of the washer next to the gear. The chamfer or rounded side must face towards the shifting keys. 44

Some units will use a stepped thrust washer; place the washer onto the shaft so that the step in the washer is out and away from the shifting gears. 8. The end of the shifter/brake shaft (opposite the shifting gears) has a spline. Install the spur gear on the spline that drives the output gear. Next install the thrust washer, bushing and “O” ring.

WASHER

WASHER

13. Install shifter assembly and pack 26 oz. (769 ml) Bentonite grease around bearings, gearing, and top of shift fan. Then reinstall the cover on the case. Torque cap screws 90-100 inch pounds (10.211.3 Nm). 14. Clean the mating surfaces of the case and cover. Place a continuous thin bead of sealant all around the seam; use Loctite Gasket Eliminator #515, Tecumseh part number 510334 or the Loctite Silicone RTV 598, Tecumseh Part number 788093.

FLAT BRONZE BUSHING

9. To assemble the output shaft assembly, place a washer and then the bronze bushing with the collar (flat down) next to the pinion. Place the output gear over the pinion as in the diagram above. There is a washer on the outside of the gear.

15. Install index ball, spring, and set screw in that order into cover, and slowly tighten the screw one (1) turn below flush. If unit contains a neutral start switch, reinstall it now. Check for binding by turning the input shaft.

APPLY LUBRIPLATE

10. After both shafts are completed, place the flanged bushings on each end. Notice that one is larger than the other. NOTE

BRAKE BRACKET

The “V” notch on the bushing fits into the recess “V” in case. 11. DIFFERENTIAL ASSEMBLY When assembling this unit, first make sure all parts are there, because the unit is put together in your hands and placed in the case at the same time. Axles and gears must be on the center line of the ring gear. When installed in the case the bearing block must have the flange to the left hand side. The bearing block in the cover must have the flange to the right hand side. BEARING BLOCK

16. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flatwasher, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. Install the brake assembly. Install the transmission on the equipment. Adjust the brake linkage to disengage when the clutch is engaged. The brake and linkages may vary. Consult the equipment owner's manual.

12. Before installing the differential into the case, apply Bentonite grease to the axle bearing areas.

Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury. WARNING

SHIFT FORK FAN ASSY.

45

900 SERIES TRANSAXLE

LUBRICATION Permanent Lubrication 26 oz. (769 ml) of Bentonite grease Part No. 788067C (No acceptable substitute)

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

46

CHAPTER 7. 910 SERIES TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury.

DISASSEMBLY OF TRANSAXLE Clean the outside surface of transaxle. Position shift lever in neutral as indicated by the shift pattern. 1. The unit may have the OEM option of a neutral start switch; remove the switch. 2. Some 910 Series transaxles will have a Allen head setscrew, spring and detent ball. Remove these and the cap screws that fasten the cover to the case. 3. Push the shift rod through the cover and lift off. Then remove the shifter assembly (which includes the shift rod, and shifter fan and lift out of case.

WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury. WARNING We caution you against the use of aftermarket variations of braking systems, adjustments and service of these components. Removing or altering factory installed parts my affect performance and could result in death or serious injury. • Servicing the braking system will void your warranty. See your Authorized Tecumseh Servicing Dealer.

4. Remove the two brake bracket screws and remove brake assembly. 5. Remove the grease from the unit as the parts are removed. Prior to removal of gear shaft assemblies from the case, the shifter fan may be removed. Note the position of the parts before removal. Some parts may come off the shafts upon removal. NOTE Bentonite grease may stain clothing. Care should be used when handling. 6. Remove the top bearing block on the bull gear of the differential. Remove the bull gear, bevel pinion gears with center shaft and the axles.

GENERAL The 910 series is available with 1 speed forward and 1 reverse.

OUTPUT SHAFT

SHIFTER/BRAKE SHAFT

INPUT SHAFT COVER CASE HEX SCREWS

SHIFT ROD

I.D. TAG DIFFERENTIAL REMOVED

IDENTIFICATION This unit contains an aluminum tag showing the model number. 47

7. Remove the output shaft assembly and the shifter/ brake shaft assembly. SHIFTER/BRAKE SHAFT

3. The large beveled shifting gears can be placed onto the shifter/brake shaft. The bevels on the gears face each other and are separated with a neutral spacer. Push shifting keys into the neutral spacer. Then place a thrust washer, bronze bushing, and an “O” ring on the shaft. The spur gear, washer, bushing and “O” ring are assembled to the other end of the shaft.

OUTPUT SHAFT REMOVED

8. The input shaft can also be removed and inspected or serviced. Remove the snap ring on the bevel gear and pull the shaft through the case. The square cut “O” ring must be replaced if the shaft is removed.

BEVEL GEARS SPUR GEAR

Tool part No. 670251, is used for removal and installation of needle bearings for the input shaft. The needle bearing on the inboard side is installed .135 - .150” (3.43-3.81 mm) below flush.

SPACER

NOTE Needle bearings are lubricated with E.P. grease. DO NOT USE BENTONITE ON NEEDLE BEARINGS. For maximum gear train life use only Bentonite grease on all shafts and gears, Tecumseh part number 788067C. INPUT SHAFT

NEEDLE BEARING FLUSH WITH HOUSING

RETAINING RING WASHER NEEDLE BEARINGS

SQUARE CUT "O" RING

FLAT SIDE

BEVELED SIDE

4. Place the shifter/brake shaft assembly in the case.

.135" (3.43mm) .150" (3.82mm) THRUST WASHER

BEVEL GEAR RETAINING RING

REASSEMBLY 1. Apply E.P. grease between the bearings in the cover and install the input shaft, bevel gear and snap ring.

5. Place the output gear onto the output pinion. Install the thrust washers and bushings. OUTPUT GEAR SHIFTER/BRAKE SHAFT

COLLAR

KEYS

2. Grease both keyways and slide keys and collar on shifter/brake shaft. 48

OUTPUT PINION

OUTPUT SHAFT ASSEMBLY INPUT SHAFT

9. Install the shifting fan with the pin in the groove of the shifting collar. Grease the top of the shift fan. Fill the unit with 18 oz. (532 ml) of Bentonite grease. Install the top bearing block with the flange to the right. 10. Clean the mating surfaces of the case and cover; place a continuous thin bead of sealant all around the seam. Use Loctite Gasket Eliminator #515, Tecumseh part number 510334 or the Loctite Silicone RTV 598, Tecumseh part number 788093.

LOWER BEARING BLOCK (FLANGE TO THE LEFT)

11. Make sure that the tabs of all the bushings are in their “V” notches, install the cover and torque the cap screws to 90-100 inch pounds (10.2-11.3 Nm).

6. Insert the output shaft assembly into the case. 7. Prior to installing the differential into the case, apply Bentonite grease to the axle bearing surfaces. BEVEL PINION GEAR ASSEMBLY

BULL GEAR

12. Reinstall the ball, spring and set screw on the models that have them. The setting for the screw is flush to the cover. Check for binding by turning the input shaft. APPLY LUBRIPLATE

BRAKE BRACKET

AXLE BEVEL GEARS

NOTE The differential must be assembled out of the case and then placed in the case. 8. Insert the lower bearing block into the case with the flange to the left. (See diagram on the top of this page.) Place the center shaft with the bevel pinion gears into the bull gear of the differential. Center the bevel gear on the longest axle with the pinion gears of the differential. This axle goes up to the side of the bull gear where the center shaft is located. On the opposite side of the bull gear, center the bevel gear with the other axle. Pick up the entire unit and place it in the case as an assembly. Reposition the rubber seals on the ends of the axles. (If damaged or old, replace them). NOTE With models that have an offset input, the differential assembly begins with the shortest axle.

13. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flatwasher, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. Install the brake assembly. Install the transmission on the equipment. Adjust the brake linkage to disengage when the clutch is engaged. The brake and linkages may vary. Consult the equipment owner's manual.

Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury. WARNING

SHIFTER FAN

RUBBER SEAL

49

910 SERIES TRANSAXLE

LUBRICATION Permanent Lubrication 18 oz. (532 ml) of Bentonite grease Part No. 788067C

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

50

CHAPTER 8. 915 SERIES / 940 SERIES TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury.

IDENTIFICATION TAG

DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury.

IDENTIFICATION

WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

DISASSEMBLY OF TRANSAXLES

WARNING

WARNING We caution you against the use of aftermarket variations of braking systems, adjustments and service of these components. Removing or altering factory installed parts my affect performance and could result in death or serious injury. • Servicing the braking system will void your warranty. See your Authorized Tecumseh Servicing Dealer. OPTIONAL INPUT LOCATION A INPUT COVER/CASE HEX B INPUT SCREWS (17)

BRAKE BRACKET SCREWS

INPUT SHAFT

SHIFT ROD

NEUTRAL START SWITCH LOCATION (OPTIONAL)

GENERAL The 915 series transaxle has a sculptured case, gear driven reverse and a unique power flow. The 915 series has 3, 4, 5 or 6 speeds forward and 1 speed reverse. The model pictured throughout this section utilizes an A input. Assembly variations for models with a B input or reverse input will be explained in the appropriate segment.

This unit contains an aluminum tag showing the model number.

Clean the outside surface of transaxle. Position shift lever in neutral as indicated by the shift pattern. 1. The unit may have the OEM option of a neutral start switch, remove the switch. 2. 915/940 Series transaxles will have a Allen head setscrew, spring and detent ball. Remove these and the cap screws that fasten the cover to the case. 3. Push the shift rod through the cover and lift off. Then remove the shifter assembly (which includes the shift rod, and shifter fan) and lift out of case. 4. Remove the “O” ring from the top of the shifter rod. INDEX BALL AND SPRING LOCATION SHIFTER/BRAKE/ OUTPUT SHAFT ASSEMBLY

COUNTERSHAFT ASSEMBLY OPTIONAL SHIFT ROD LOCATION

SHIFT ROD ASSEMBLY

5. Remove the two brake bracket screws and remove brake assembly. 6. Remove the grease from the unit as the parts are removed. NOTE Bentonite grease may stain clothes. Care should be used when handling.

51

940 SERIES The 940 Series is identical to the 915 Series with the exception of 3 added bronze bushings. These bushings is located on the shifter brake shaft one opposite the brake rotor end. The other two are located on the spur gear shaft, one on each end. 7. Remove the bearing strap on the bull gear of the differential. Remove the bull gear, bevel pinion gears with center shaft, and the axles. Grasp the axle bevel gears between your thumb and fingers, hold together while lifting differential from the case.

9. As these assemblies are taken apart, lay the parts out in a systematic order. This will help to make reassembly and inspection of parts easier. Clean grease from each part as the parts are laid out. To remove keys from the shifter/brake/output shaft you must remove the large snap ring from its groove. Be careful not to stretch or twist the snap ring; it is not necessary to remove the snap ring from shaft. SHIFTER/BRAKE SHAFT ASSEMBLY

BEARING STRAP DIFFERENTIAL BULL GEAR AXLE BEVEL GEAR SNAP RING

10. The input shaft can also be removed and inspected or serviced. Remove the snap ring on the bevel gear and pull the shaft through the case. The square cut “O” ring must be replaced if the shaft is removed. 8. There are two (2) shaft assemblies in this transaxle; the countershaft and the shifter/brake/output shaft assembly. Remove these two shafts as complete assemblies from the case.

Tool part No. 670251, is used for removal and installation of needle bearings for the input shaft. The needle bearing on the inboard side is installed .135 - .150” (3.43-3.81 mm) below flush.

NOTE

NOTE

Depending on the rotation of the countershaft gears, the reverse idler assembly will be located either above the reverse gears and held in place by bosses in the cover or below the reverse gears and held in place by bosses in the case. The reverse idler assembly will always be located against the thrust of the countershaft reverse gear.

Needle bearings are lubricated with E.P. grease. DO NOT USE BENTONITE ON NEEDLE BEARINGS. For maximum gear train life use only Bentonite grease on all shafts and gears, Tecumseh part number 788067C.

NEEDLE BEARING FLUSH WITH HOUSING SQUARE CUT "O" RING

BEVEL GEAR

COUNTERSHAFT ASSEMBLY

52

SHIFTER/BRAKE/ OUTPUT SHAFT ASSEMBLY REVERSE IDLER ASSEMBLY

RETAINING RING

INPUT SHAFT RETAINING RING WASHER NEEDLE BEARINGS .135" (3.43 mm) .150" (3.81 mm) THRUST WASHER

REASSEMBLY

OUTPUT GEAR

LARGE BEVEL GEAR

1. Apply grease between the bearings in the cover and install the input shaft, square cut seal, thrust washers, bevel gear and snap ring. SNAP RING GROOVE

THIN SHIFTING WASHER SNAP RING

2. Grease all keyways and slide keys and collar onto the shifter/brake/output shaft. On models which have a inner diameter recess cut into one side of the shift collar, the recess side must face toward the gears and snap ring for proper gear selection. Place the large snap ring back into the snap ring groove. On five speed models that do not use the large bevel gear for the highest speed, an additional neutral spacer will be placed between the snap ring and the shift collar. REVERSE SHIFT GEAR SHIFT GEARS

4. On the Shifter/brake shaft the last shifting washer will be a thin flat washer installed prior to the large bevel gear. The style of input will determine how the large bevel gear will be installed. In the model pictured, input “A” is used and the bevel is inward towards the keys. On models with a “B” input the bevel will be outward or away from the keys. In both instances the gear cut directly onto the large bevel gear will be toward the outside of the case. Install a washer and then the output gear. The output gear has an inner diameter recess on one end, this recess must face toward the large bevel gear. Two washers are installed next to the output gear followed by a bronze bushing and rubber “O” ring. Then place a washer on the opposite end of the shaft to complete the assembly of the shifter/ brake shaft.

SHIFT WASHERS REVERSE GEAR COLLAR

NEUTRAL SPACER

SHIFTING WASHER

CUT OUT SIDE

FLAT SIDE

NOTE As all the gears are placed back into the assembly, each should be packed with Bentonite grease. 3. The shafts in this transaxle can be assembled separately. After replacing the snap ring into its’ groove, place the reverse shifter gear onto the shaft with the flat side next to the snap ring. Push the shifting keys through the reverse gear and push the neutral spacer over the end of the keys and pull the neutral spacer and reverse gear up against the snap ring. Next place the shifting gear onto the shaft with the flat side next to the neutral collar.

LOCATION FOR SPACER (SOME MODELS)

5. The countershaft must have the longer unsplined end toward the outside or brake side of the case and the shorter unsplined end toward the shifter assembly. The wide washer or spacer is placed on the longer unsplined end followed by the largest spur gear. If assembling a six speed or on some five speed models, a spacer will be placed next to the largest spur gear. On all other models, leave a space the width of the large bevel gear and then assemble the remainder of the spur gears with the reverse spur gear assembled with the collar side inward. The small washer is placed next to the reverse spur gear to complete the counter shaft assembly. The two assembled shafts can now be placed into the transaxle case. If the model has the reverse idler held in place by the case, insert the reverse idler into the case prior to the shafts.

Then place a shifting washer onto the shaft with the rounded edge towards the shifting keys. Continue this procedure until all the gears and washers have been added in their proper sequence. 53

NOTE Depending on the rotation of the countershaft gears, the reverse idler assembly will be located either above the reverse gears and held in place by the bosses in the cover, or below the reverse gears and held in place by the bosses in the case. The reverse idler assembly will always be located against the thrust of the countershaft reverse gear. Make sure that the tab on the bronze bushing is located into the recess provided in the case.

Clean the mating surfaces of case and cover; place a continuous thin bead of sealant all around the seam. Use Loctite Gasket Eliminator #515 , Tecumseh part number 510334 or the Loctite Silicone RTV 598, Tecumseh part number 788093A.

8. Guide the cover over the shift rod and position onto the case. Install the cover cap screws and torque 90-100 inch pounds (10.2-11.3 Nm). Install the neutral start sensing switch if applicable. Replace the square cut “O” ring on the exposed shift rod. Check for binding by turning input shaft.

NOTE The differential must be assembled out of the case and then placed in the case. Apply Bentonite grease anywhere the axle contacts the case. 6. Place the center shaft with the bevel pinion gears into the bull gear of the differential. Center the bevel gear of one axle with the pinion gears of the differential. Center the bevel gear of the other axle to the pinion gears of the differential. Pick up the entire unit and place it in the case as an assembly. Reposition the rubber seals on the ends of the axles in their bosses. (If damaged or old replace them). 7. Install the shifter assembly, bearing strap and reverse idler assembly (if applicable). Pack the transaxle with the remaining Bentonite grease (10 ounces [296 ml] total). Replace the spring, set screw and the detent ball.

APPLY LUBRIPLATE

BRAKE BRACKET

9. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flatwasher, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. Install brake assembly. Install the transmission on the equipment. Adjust the brake linkage to disengage when the clutch is engaged. The brake and linkages may vary. Consult the equipment owner's manual. WARNING Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury.

54

915 SERIES / 940 SERIES TRANSAXLES

LUBRICATION Permanent Lubrication 10 oz. (296 ml) of Bentonite grease Part No. 788067C

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

55

CHAPTER 9. 920 SERIES TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury.

DISASSEMBLY OF TRANSAXLE Clean outside surface of transaxle. Position shift lever in neutral as indicated by the shift pattern. 1. The unit may have the OEM option of a neutral start switch; remove the switch. 2. Remove the Allen head setscrew, spring and detent ball. Remove the cap screws that fasten the cover to the case. 3. Push the shift rod through the cover and lift off. Then remove the shifter assembly (which includes the shift rod and shifter fan) and lift out of case.

WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury. NOTE Due to the many variations of equipment braking systems, adjustments and repair to these components and linkages are not considered warranty.

NOTE Some models will have the index ball and spring on the case end of the shift rod. Be careful not to lose parts when removing shift rod assembly. 4. Remove the two brake bracket screws and remove the brake assembly. 5. Remove the grease from the unit as the parts are removed. NOTE Bentonite grease may stain clothes. Care should be used when handling.

GENERAL The 920 series transaxle is very similar to the 900 series. The 920 series is available in 5, 6, or 7 speeds forward and 1 speed reverse. The 7 speed transaxle is shown in this section of this manual. CASE COVER HEX SCREWS

INPUT SHAFT SHIFT ROD

A

B ID TAG

IDENTIFICATION This unit contains an aluminum tag showing the model number. 56

6. Remove the top bearing block on the bull gear of the differential. Remove the bull gear, bevel pinion gears with center shaft and the axles. Grasp the axle bevel gears between your thumb and fingers, holding together while lifting differential from case.

7. There are three (3) shaft assemblies in this transaxle; the output shaft, the countershaft, and the shifter/ brake shaft assembly. Remove these assemblies as complete as possible from the case. COUNTERSHAFT ASSEMBLY

REASSEMBLY 1. Apply grease between the bearings in the cover and install the input shaft, square cut seal, thrust washers, bevel gear and snap ring.

OUTPUT SHAFT ASSEMBLY SHIFT COLLAR

SHIFTER/BRAKE SHAFT

KEYS

2. Grease both keyways and slide the shift keys and collar onto the shifter/brake shaft. SHIFTER/BRAKE SHAFT ASSEMBLY

8. As these assemblies are taken apart, lay the parts out in a systematic order. This will help to make reassembly easier and inspection of all parts possible. Clean each part of grease as the parts are laid out.

3. The countershaft and the shifter/brake shaft should be assembled at the same time. Start by placing the reverse chain over the reverse sprockets. Make sure the collars on the sprockets are on the same side of the chain and install the sprocket onto the shifter/brake shaft with the collar away from the shift keys.

LARGE INNER DIAMETERS FACE EACH OTHER

9. The input shaft can also be removed and inspected or serviced. Remove the snap ring on the bevel gear and pull the shaft through the case. The square cut “O” ring must be replaced if the shaft is removed. Tool part No. 670251, is used for removal and installation of needle bearings for the input shaft. The needle bearing on the inboard side is installed .135" - .150" (3.43-3.81 mm) below flush. INPUT SHAFT

NEEDLE BEARING FLUSH WITH HOUSING

RETAINING RING WASHER NEEDLE BEARINGS

SQUARE CUT "O" RING

.135" (3.43 mm) .150" (3.81 mm) THRUST WASHER

BEVEL GEAR RETAINING RING

SPROCKET COLLARS

LARGER RADIUS SPACER TOWARD SHIFT KEYS

REVERSE CHAIN AND SPROCKETS

NEUTRAL SPACER

Next place the neutral spacers onto the shifter/ brake shaft with larger inner diameter sides facing together, and the spacer with the largest inner diameter radius toward the shift keys. Push the shifting keys through the reverse sprocket and the first neutral spacer. Pull the neutral spacers and the reverse sprocket up against the shoulder of the shifter/brake shaft. NOTE There have been a few 900 models built with identical neutral collar halves. These can be installed in either direction.

NOTE Needle bearings are lubricated with E.P. grease. DO NOT USE BENTONITE on needle bearings. For maximum gear train life use only Bentonite grease on all shafts and gears, Tecumseh part number 788067C.

57

*4. Insert the countershaft into the smaller reverse sprocket. Insert a thin thrust washer next to the sprocket (collar side) and then install the large bevel gear with the bevel towards the reverse sprocket. Place another thin thrust washer on the back side of the bevel gear.

SPACER

NOTE As all the gears are placed back onto the assembly, each should be packed with bentonite grease. BEVEL GEAR

COUNTERSHAFT SPUR GEAR "O" RING

6. Place the spacer on the countershaft next to the reverse sprocket. Then place a thrust washer on each end of the countershaft and insert the bronze bushings. Place the large washer on the end of the shifter/ brake shaft, followed by the bronze bushing and the “O” ring. 7. Place the spur gear onto the splines on the other end of the shifter/brake shaft. The thin washer, bushing, and “O” ring conclude the assembly of these two shafts. WASHER

SHIFTING WASHER

CUT OUT SIDE

FLAT SIDE

5. Build the gears on the countershaft and shifter/ brake shaft alternately, meshing each gear with it’s mating gear on the opposite shaft. The first gear on the shifter/brake shaft would be the largest of the shift gears. Place this gear next to the neutral collar with the flat side of the gear next to the collar. (See the drawing on the prior page). Then place a shifting washer onto the shifter/brake shaft with the rounded edge towards the shifting keys. Continue this procedure until all the gears on both shafts have been added.

WASHER OUTPUT PINION

BUSHING

OUTPUT GEAR

BUSHING

8. Place the output gear on the stepped end of the output pinion. Place the thrust washers and the bronze bushings on the ends of the output shaft. Install these three shaft assemblies back into the case. Make sure that the tabs of all bushings are in their “V” notches in the case. NOTE The differential must be assembled out of the case and then placed in the case. Apply bentonite grease to axle contact areas of case.

NOTE It is not only important that gears match up according to diameter, but also to thickness.

*ASSEMBLY VARIATIONS On models which are driven from the opposite side of the input bevel gear, the following changes take place. A slightly thicker large bevel gear is placed on the countershaft with the bevel facing the spur gears and in the previous location of the spacer. The thickness of the gear eliminates the need for the washers on each side of the large bevel gear. The reverse chain and sprocket are also turned 180o, which places the sprocket collars away from shifting gears and spur gears. The spacer is then placed in the previous location of the large bevel gear next to the reverse sprocket.

58

BEVEL GEAR

12. Guide the cover over the shift rod and position onto the case. Install the cover cap screws and torque 90-100 inch pounds (10.2-11.3 Nm). Install the neutral start sensing switch if applicable. Replace the square cut “O” ring on the exposed shift rod.

CENTER SHAFT

Replace the detent ball, spring and set screw and turn set screw one (1) turn below flush. Install the neutral start sensing switch if applicable. BEVEL GEAR

BEVEL PINION GEARS

Check for binding by turning the input shaft.

BULL GEAR APPLY LUBRIPLATE

9. Place the center shaft with the bevel pinion gears into the bull gear of the differential. Center the bevel gear on the longest axle with the pinion gears of the differential. Center the bevel gear of the other axle on the other side. Pick up the entire unit and place it in the case as an assembly. Reposition the rubber seals on the ends of the axles in their bosses. (If damaged or old replace them).

10. Install the shifter assembly and bearing strap, pack the transaxle with the remaining Bentonite grease (30 ounces [887 ml] total). Apply grease to the top of the shifter fan.

BRAKE BRACKET

13. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flat washer, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. Install brake assembly. Install the transmission on the equipment. Adjust the brake linkage to disengage when the clutch is engaged. The brake and linkages may vary. Consult the equipment owner's manual.

WARNING Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury. 11. To seal the case and cover at the end of the shifter/ brake shaft, a flat plug is placed on the opposite end of the brake assembly. Clean the mating surfaces of case and cover; place a continuous thin bead of sealant all around the seam. Use Loctite Gasket Eliminator # 515, Tecumseh part number 510334 or the Loctite Silicone RTV 598, Tecumseh part number 788093A.

59

920 SERIES TRANSAXLES

LUBRICATION Permanent Lubrication 30 oz. (887 ml) of Bentonite grease Part No. 788067C

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

60

CHAPTER 10. 930 SERIES TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury.

IDENTIFICATION This unit contains an aluminum tag showing the model number. COVER CASE HEX SCREWS

WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. Use approved safety procedures WARNING with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury. NOTE Due to the many variations of equipment braking systems, adjustments and repair to these components and linkages are not considered warranty. INPUT SHAFT

BRAKE BRACKET SCREWS

DISASSEMBLY OF TRANSAXLE Clean outside surface of transaxle. Position shift lever in neutral as indicated by the shift pattern. 1. The unit may have the OEM option of a neutral switch; remove the switch. 2. Remove the Allen head setscrew, spring and detent ball. Remove the cap screws that fasten the cover to the case. 3. Push the shift rod through the cover and lift off. Then remove the shifter assembly (which includes the shift rod, and shifter fan) and lift out of case. BEARING STRAP

DIFFERENTIAL IDENTIFICATION TAG

INDEX BALL, SPRING AND SET SCREW OUTPUT SHAFT ASSEMBLY SHIFT ROD

COVER/CASE BRAKE BRACKET SCREWS HEX SCREWS (BRAKE CAN BE ON RIGHT NEUTRAL START SWITCH OR ON LEFT SIDE) LOCATION (OPTIONAL)

SHIFTER/BRAKE SHAFT ASSEMBLY COUNTERSHAFT ASSEMBLY

SHIFTER ASSEMBLY LOCATION

4. Remove the “O” ring from the top of the shifter rod. GENERAL The 930 series transaxle is very similar to the 920 series. The 930 series is available in 3 through 7 speeds forward and 1 speed reverse. The model pictured throughout this section is the most popular type. There are models which operate in the opposite direction without changing the input location. Throughout this section an asterik (*) will direct the reader to the end of the section where the differences between these models are explained.

5. Remove the two brake bracket screws and remove brake assembly. 6. Remove the grease from the unit as the parts are removed. NOTE Bentonite grease may stain clothes. Care should be used when handling.

61

BEARING STRAP

DIFFERENTIAL BULL GEAR AXLE BEVEL GEAR

INPUT SHAFT

NEEDLE BEARING FLUSH WITH HOUSING

RETAINING RING WASHER NEEDLE BEARINGS

SQUARE CUT "O" RING

.135" (3.43 mm) .150" (3.81 mm) THRUST WASHER

BEVEL GEAR RETAINING RING

7. Remove the bearing strap on the bull gear of the differential. Remove the bull gear, bevel pinion gears with center shaft and the axles. Grasp the axle bevel gears between your thumb and fingers and hold together while lifting differential from case. OUTPUT SHAFT ASSEMBLY

COUNTERSHAFT ASSEMBLY

10. The input shaft can also be removed and inspected or serviced. Remove the snap ring on the bevel gear and pull the shaft through the case. The square cut “O” ring must be replaced if the shaft is removed. Tool part No. 670251, is used for removal and installation of needle bearings for the input shaft. The needle bearing on the inboard side is installed .135 - .150” (3.43-3.81 mm) below flush. NOTE Needle bearings are lubricated with E.P. grease. DO NOT USE BENTONITE on needle bearings. For maximum gear train life use only Bentonite grease on all shafts and gears, Tecumseh part number 788067C. REASSEMBLY 1. Apply grease between the bearings in the cover and install the input shaft, square cut seal, thrust washers, bevel gear and snap ring.

SHIFTER/BRAKE SHAFT ASSEMBLY

8. There are three (3) shaft assemblies in this transaxle; the output shaft, the countershaft, and the shifter/ brake shaft assembly. Remove these assemblies as complete as possible from the case.

SHIFTER/BRAKE SHAFT

KEYS (2 OR 4)

SHIFT COLLAR

SNAP RING

2. Grease all keyways and slide keys and collar onto the shifter/brake shaft. (There are both 2 and 4 key models). Place the large snap ring back into the snap ring groove. On models which have an inner diameter recess cut into one side of the shift collar, the recess side must face toward the gears and snap ring for proper gear selection. SNAP RING GROOVE

SNAP RING

9. As these assemblies are taken apart, lay the parts out in a systematic order. This will help to make reassembly easier and inspection of all parts possible. Clean each part of grease as the parts are laid out. To remove keys from the shifter/brake shaft you must first remove the large snap ring from the snap ring groove. Be careful not to stretch or twist the snap ring; it is not necessary to remove the snap ring from the shaft.

62

REVERSE CHAIN AND SPROCKETS SHIFT COLLAR

SPROCKET COLLARS

SNAP RING WASHER

NEUTRAL SPACER

WASHER

SPACER BUSHING

BUSHING

*3. To assemble this transaxle the countershaft and the shifter/brake shaft should be assembled at the same time. Start by placing the reverse chain over the reverse sprockets. Make sure that the collars on the sprockets are on the same side of the chain. Install a large washer onto the shifter/brake shaft next to the snap ring and then the large sprocket with the collar away from the shifting keys. Push the shifting keys through the reverse sprocket and push the neutral spacer over the end of the keys. Pull the neutral spacer and reverse sprocket up against the snap ring on the shifter/brake shaft. WASHER SPUR GEAR

THRUST WASHER

BEVEL GEAR

THRUST WASHER

"O" RING WASHER

*6. Place the spacer on the countershaft next to the reverse sprocket. Then place a thrust washer on each end of the countershaft and insert the bronze bushings. Place the large washer on the end of the shifter/ brake shaft, the bronze bushing and the “O” ring.

COUNTERSHAFT SPUR GEAR WASHER

*4. Insert the countershaft into the smaller reverse sprocket. Insert a thin thrust washer next to the sprocket (collar side) and then install the large bevel gear with the bevel towards the reverse sprocket. Place another thin thrust washer on the back side of the bevel gear. NOTE As all the gears are placed back into the assembly, each should be packed with Bentonite grease.

BUSHING

7. Place the spur gear onto the splines on the other end of the shifter/brake shaft. The thin washer and bushing conclude the assembly of these two shafts.

BUSHING SHIFT WASHERS

WASHER

WASHER

SPUR GEARS

SHIFT GEARS

SHIFTING WASHER

CUT OUT SIDE

FLAT SIDE

5. Build the gears on the countershaft and shifter/ brake shaft alternately, meshing each gear with its mating gear on the other shaft. The first gear on the shifter/brake shaft would be the largest of the shifting gears. Place this gear next to the neutral spacer with the flat side of the gear next to the spacer.

OUTPUT PINION

BUSHING OUTPUT GEAR

8. Place the output gear on the stepped end of the output pinion. Place the thrust washers on each end and then the bronze bushings. Install these three shaft assemblies back into the case. Make sure that the tabs of all the bushings are in their “V” notches in the case.

Then place a shifting washer onto the shifter/brake shaft with the rounded edge towards the shifting keys. Continue this procedure until all the gears on both shafts have been added. NOTE It is not only important that gears match up according to diameter, but also to thickness.

* See Assembly Variations on page 64

63

BEVEL GEAR

CENTER SHAFT

APPLY LUBRIPLATE

BRAKE BRACKET BEVEL GEAR

BEVEL PINION GEARS BULL GEAR

NOTE The differential must be assembled out of the case and then placed in the case. Apply bentonite grease to axle contact areas of case. 9. Place the center shaft with the bevel pinion gears into the bull gear of the differential. Center the bevel gear on the longest axle with the pinion gears of the differential. Center the bevel gear on the other axle with the other side. Pick up the entire unit and place it in the case as an assembly. Reposition the rubber seals on the ends of the axles in their bosses. (If damaged or old replace them).

12. Apply a light film of lubriplate to the inside lever which contacts the brake pins, the outside of the lever which contacts the flat washer, and between the shaft O.D. and the I.D. of the splined brake disc. The brake pads and brake disc must be free of grease and oil. Install brake assembly. Install the transmission on the equipment. Adjust the brake linkage to disengage when the clutch is engaged. The brake and linkages may vary. Consult the equipment owner's manual. WARNING Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury.

10. Install the shifter assembly and bearing strap, pack the transaxle with the remaining Bentonite grease (30 ounces total) (887 ml). Apply grease to the top of the shifter fan.

*

ASSEMBLY VARIATIONS On models which are driven from the opposite side of the input bevel gear the following changes take place. A slightly thicker large bevel gear is placed on the countershaft with the bevel facing the spur gears and in the previous location of the spacer. The thickness of the gear eliminates the need for the washers on each side of the large bevel gear, which places the sprocket collars away from the shifting gears and spur gears. The reverse chain and sprocket is also turned 180o. The spacer is then placed in the previous location of the large bevel gear next to the reverse sprocket.

11. To seal the case and cover at the end of the shifter/ brake shaft, a flat plug is placed on the opposite end of the brake assembly. Clean the mating surfaces of case and cover; place a continuous thin bead of sealant all around the seam. Use Loctite Gasket Eliminator # 515, Tecumseh part number 510334 or the Loctite Silicone RTV 598, Tecumseh part number 788093A. Install cover screws and torque to 90-100 inch pounds (10.2-11.3 Nm). Replace the detent ball, spring and set screw and turn set screw one (1) turn below flush. Install the neutral start sensing switch if applicable. Check for binding by turning input shaft. 64

930 SERIES TRANSAXLES

LUBRICATION Permanent Lubrication 30 oz. (887 ml) of Bentonite grease Part No. 788067C

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

65

CHAPTER 11. MST200 SERIES TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury.

IDENTIFICATION The MST has a decal placed at the rear of the unit and to the right of the differential gear section. This makes it easily visible without having to remove any obstructions to view it.

WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

IDENTIFICATION TAG

STEPS TO TAKE BEFORE DISASSEMBLY. 1. Clean the outside surface of the transaxle. 2. Position the shift lever in the neutral position.

WARNING We caution you against the use of aftermarket variations of braking systems, adjustments and service of these components. Removing or altering factory installed parts my affect performance and could result in death or serious injury. • Servicing the braking system will void your warranty. See your Authorized Tecumseh Servicing Dealer.

REMOVE FILL PLUG

SQUARE CUT O-RING AND PUSH NUT

3. Remove the oil drain / fill plug located on top of the unit. This can be done by using a needle nose pliers to pull the plug out. Drain all of the oil from the unit. CUSTOMER MOUNT POINTS (PRY POINT)

GENERAL The MST (Manual Shift Transaxle) 200 is a sealed unit which uses 16 oz. (473 ml) of 80W90 gear lube (part #730229B). The MST series is available with up to 6 speeds forward and one reverse. It has a contoured case and cover. Its unique gear design system uses the input gear to drive both the forward and reverse motion. It also eliminates the recess previously found on shifter brake shaft spur gears. Thrust washers are used on all transaxles to protect stationary surfaces from rotating surfaces. To determine the location of the thrust washer, check its inside diameter and compare it to the outside diameter of the shaft. If the fit is loose, it is out of position. The flat washer used on the shifter shaft (brake end) must have a diameter large enough to stop the keys from going past the end of the gear slots. 66

4. Remove the neutral start switch, if installed (O.E.M. option). 5. Remove the push nut (if equipped) and square cut "O" ring, from the top of the shift fork shaft.

ALLEN HEAD SET SCREW SPRING

DETENT BALL

6. Remove the set screw, spring and detent ball.

DISASSEMBLY 1. Remove the self-tapping hex head screws that hold the cover to the case and the two center screws located on the bottom (case side) of the transaxle. When prying the crankcase from the crankcase cover use specified mount points. Failure to do so may result in equipment damage. CAUTION

2. With a rubber or leather mallet tap down on the shift lever rod while removing the cover from the case. NOTE If rust has occurred on the shaft, remove it with emery cloth before removing the shaft to prevent damage. 3. Remove the two brake bracket screws and remove the brake assembly. 4. Remove the differential ring gear, and bevel pinion gears with the center shaft drive pin and the axles. Grasp the axle bevel gears between your thumb and fingers. Hold the entire assembly together while lifting the differential from the case. NOTE: When a "B" input is used the input bevel gears will be opposite of this picture. The drive spline on this shaft also moves.

SEAL BUSHING

CHAMFERED SHIFT WASHERS THRUST WASHER

THRUST WASHER SPUR GEAR NOTE: INSIDE RECESS FACES KEYS

7. To disassemble the shifter/brake shaft, start on the spur gear side. Remove the oil seal, the bronze bushing and thrust washer. Remove all of the shifter spur gears (and spacers if used) and shift washers. Remove the neutral collar, reverse gear and thrust washer. On the output side of the shifter/brake shaft remove the bronze bushing, thrust washer, and output spur gear. To remove the shift keys from the shifter/brake shaft, you must first expand the large snap ring from the snap ring groove. Be careful not to stretch or twist the snap ring, it is not necessary to remove the snap ring from the shaft. Place the expanded snap ring onto the shifter/brake shaft and slide the shift keys and shift collar off the shifter/brake shaft. NOTE: When a "B" input is used the input bevel gears will be opposite of this picture. The drive spline on this shaft also moves. REVERSE FOR B INPUT

REVERSE DRIVE BEVEL GEAR

5. There are three shaft assemblies in this transaxle. The countershaft, shifter/brake shaft and output shaft. Remove the shifter fork assembly and then remove the shaft assemblies from the case. NOTE Before you begin disassembly, ask the customer if the unit has been serviced previously by a technician or perhaps himself. They may have misassembled it. 6. As these assemblies are taken apart, lay the parts out in a systematic order. This should help to make the reassembly easier.

FORWARD DRIVE BEVEL GEAR

8. To disassemble the counter spur gear shaft, remove the bushing, thrust washer and spur gears (and spacers if used) the last spur gear is held in place by a retaining ring. Remove the retaining ring and slide the spur gear and forward drive bevel gear off the splined end of the shaft. The bushing, thrust washer and reverse drive bevel gear can be removed from the unsplined end of the shaft.

Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury. WARNING

67

REASSEMBLY SPACER

The tool, part number 670251 can also be used for installation of the needle bearings for the input shaft. The inside needle bearings are installed .135" -.150" (3.43-3.81 mm) below flush. The top bearing is installed flush to the casting.

THRUST WASHERS

9. To disassemble the output shaft, remove the bushing, thrust washer, large output spur gear, spacer, small output spur gear, thrust washer, and bushing.

1. Use an EP bearing grease and apply it to the bearings in the cover. Place the seal into the cover with the grooved side of the seal visible and facing the installer. Place the snap ring and thrust washer on the input shaft and slide the shaft through the cover and seal. Place the square cut o-ring, thrust washer and input bevel gear on the shaft on the inboard side and secure them by placing a snap ring in the snap ring groove.

SNAP RING NEEDLE BEARING FLUSH WITH HOUSING OIL SEAL

BEVEL GEAR RETAINING RING

INPUT SHAFT RETAINING RING NEUTRAL COLLAR

WASHER NEEDLE BEARINGS .135" (3.43 mm) .150" (3.81 mm) THRUST WASHER

10. The input shaft can also be removed and inspected or serviced. Remove the snap ring and thrust washer on the input shaft, pull the shaft through the cover. The oil seal located on the inboard side of the cover should be replaced when reassembled. Be sure to reinstall the upper and lower thrust washers. Tool part number 670251 is used for removal of needle bearings for the input shaft.

RECESS IN KEY COLLAR

2. Next assemble the shifter brake shaft by placing the shift keys in the keyway on the shaft with the tip of the keys facing the shifter spur gear side of the shaft. Extend the collar end of the key slightly beyond the shaft. Place the shift collar in the notch provided on the shift key with the inside diameter recess on the collar facing toward the tips of the keys. Place the notch from the second key on the inside diameter of the shift collar and position the key in the slot on the shifter/brake shaft. Slide the keys and the collar onto the shaft under the snap ring. Place the snap ring back into the groove on the shaft. SEAL BUSHING

11. After clean up of all parts, a complete inspection should be done. Check for chipping or damage to the gear teeth, keys or the four key slots in the shifter gears. You also should inspect the two keyways in the shifter shaft for damage, or chipping. Worn or damaged parts must be replaced.

SPUR GEAR SPLINE

SHIFTER WASHERS THRUST WASHER

THRUST WASHER

SNAP RING

SPUR GEAR

NOTE: INSIDE RECESS FACES KEYS

3. Place the plain large thrust washer over the key tips on the spur gear side of the shaft next to the snap ring. The sequence that follows is reverse gear, the neutral collar, then 1st thru the number of gears the unit contains (largest to smallest). Between each gear place a shift washer with the chamfered I.D. facing the shift key (opposite the brakeshaft). 68

on the splined shaft with the bevel facing the reverse drive gear. A retaining ring is put on the shaft next to the spur gear between the splined sections to prevent the bevel gears from spreading. The countershaft is then completed by placing the remaining spur gears on the shaft (smallest to largest). If the spacers are used they will be placed between the final spur gear and the thrust washer with the bushing to follow. NOTE The spur gears on the countershaft can be installed in either direction. SPACER

SHIFTING WASHER

OLD STYLE

NEW STYLE

NOTE Reverse and first gear do not have a shift washer; the neutral collar compresses the key here. Shift washers have one side where the inside diameter is rounded, this rounded edge must face the shift keys. The shifter spur gears no longer have a recess on one side and do not require that they be positioned in any particular direction. Units that have less than six speeds will use a spacer in place of a gear. When this occurs it is not required to have a shift washer between the spacer and the preceding gear. When the final spur gear or spacer is in place, a thrust washer is positioned on the shaft to protect the case from the rotating gear. This washer is slightly larger then the diameter of the spacer and large enough to cover the inside diameter of the key slot portion of the shifter spur gear. Next place the bronze bushing and the oil seal on the shaft (the open side of the seal must face inward). This completes the spur gear side of the shifter brake shaft. The output side only requires the output spur gear, washer and bushing.

THRUST WASHERS

5. The output shaft is completely splined and consists of a bronze bushing, thrust washer, a large output gear, spacer, small output gear, thrust washer and bronze bushing. DIFFERENTIAL ASSEMBLY

RETAINING CLIP

6. To reassemble the differential, first inspect the axle bevel gears for damage or wear. If it is necessary to replace a gear, the mating gears must also be replaced.

REVERSE FOR "B" INPUT

4. To assemble the countershaft, place the reverse input bevel gear on the unsplined end of the shaft. Follow with a washer and a bronze bushing to complete the reverse drive side of the countershaft. The forward drive side requires the forward input bevel gear and the smallest spur gear to be placed

The differential must be assembled outside of the case and placed into the case as an assembly. Using seal protector (part # 670262) place a new seal on each shaft with the open side facing inward. Hold the longest shaft with the bevel gear and washer in your hand between the ring and middle finger. Place the bull gear and the bevel pinion gears and shaft on top of the axle shaft and bevel gear. Center the pinion gear shaft on the axle shaft and place the short axle so it is also centered on the pinion shaft.

69

10. Place a coating of grease on the shaft for easy assembly and corrosion protection. Replace the "O" ring if needed. With the cover in position over the shaft, place it onto the case and rotate the input shaft to allow the gears to mesh, and drop the cover into place. SEAL LOCATION

7. Pick up the entire assembly and place it into the case, positioning the seals in the seal pockets. When properly installed, the axle shaft should turn freely without any binding.

11. Install the cover screws and torque them to 90100 inch pounds (10-11.3 Nm). Replace the detent ball, spring and set screw. Turn the set screw down to the flush position. Install the neutral start sensing switch if applicable.

NOTE Before closing the case make sure the case and cover fit together evenly. Insure the bushings are properly positioned with the flat sides of the bushings matching the pockets of the case and cover. LOCTITE BEAD AROUND "OLD STYLE" SEALS

SEALANT AROUND TWO BOLTS FROM BOTTOM OF CASE ALLEN HEAD SET SCREW SPRING

DETENT BALL

NOTE: Detent screw must have pipe thread sealant applied to prevent oil leakage.

NOTE Do not forget to re-install the two bottom bolts. NEW "RIBBED" STYLE SEALS DON'T NEED SEALANT

WARNING Avoid blocking oil passages leading to axle shafts when applying a silicone bead to case as shown. Failure to do so may result in oil leaks and could result in death or serious injury. 8. To seal the case and cover, clean the mating surfaces and place a continuous thin bead (1/16" / 1.5 mm) of Loctite 598 Silicone RTV (part # 788093A) around the entire perimeter of the cover to prevent an oil leak. Don't forget the two bottom bolts. NOTE The axle and brake shaft seals on later production MST's have been redesigned to eliminate the need for sealant in the seal/bearing pocket area. These new seals are identified by external ribs that hold the seal in place and prevent leakage. DO NOT put sealant in the seal/bearing pockets with this new type of seal.

12. Prior to installing the brake assembly, apply a light film of lubriplate to the inside of the lever portion which contacts the pins, the outside lever which contacts the flat washer, and between the shaft O.D. and bore of the brake disc. Brake pads and the brake disc must be free of grease and oil. Install the brake assembly. OIL FILL/DRAIN HOLE

13. Refill the transaxle through the fill hole located in the cover. This unit requires 16 oz. (473 ml) of 80W90 gear lube (part #730229B). When completed, lubricate the plug lightly on the outside with oil. Use a 3/16" (4.7 mm) wood dowel placed in the plug recess to push it into the plug hole.

"O" RING

14. Install the transaxle on the equipment. Make any clutch and brake adjustments in accordance with the equipment manufacturers owners manual.

9. Before placing the cover on the case, place the shift rod and fork pins into the shift collar and the shaft into its' boss in the case. Inspect the shaft on the rod and fork for rust and burrs. 70

WARNING Follow recommended guidelines in equipment manufacturer's manual for correct brake adjustment. Failure to do so could result in excessive brake pad wear and brake failure which could result in equipment damage, death or serious injury.

CHECKING OIL LEVEL PROCEDURE: 1. Place the tractor on a level surface. 2. Depress the clutch/brake pedal, engage parking brake and place the deck in lowest cutting position. 3. Locate the rubber fill plug next to the shift rod as it enters the transaxle cover.

6. If oil is needed, we recommend using a 16 ounce (473 ml) goose neck mechanics oil can. (These are readily available at any hardware store.) Fill the unit with all 16 ounces (473 ml) of 90 wt. gear oil to the level indicated. 7. Reinstall the plug by lubricating it with a silicon spray lubricant. An installation tool can be made by using one of the following procedures. 6" (152 mm)

FILL PLUG

20" (508 mm)

ROUNDED END

3" (76 mm)

FILL PLUG PUSHER TOOL 3/16" (4.76 mm) ROD

4. Work a needle nose pliers under the lip of the plug, rocking from side to side until plug is removed. Use care to not damage the rubber plug.

8. When the plug is accessible from the battery box area, make an installation tool from 3/16" (4.76 mm) cold rolled steel rod as shown.

DIPSTICK NO. 35942 LARGE FENDER WASHER

1/2" (12.7 mm) CONTACT IS FULL

45o

STD. NO. 10 NUT

NO. 10 SCREW BOLT 2" (50 mm) LONG

5. Insert the dipstick gauge at a 45° angle (Part Number 35942). Check for approximately 1/2 inch (12.7 mm) of oil when fully inserted. This is 16 ounces (473 ml) of EP90 gear oil.

9. If working from the bottom or side, use a No. 10 bolt screw approximately 2 inches (50 mm) long with full threads. Then find a large fender washer and nut for the screw. The washer will give your fingers a large surface area to push down on for reinstallation of the plug. The blunt end of a TORX 30 bit works well also.

71

CHAPTER 12. 1200 SERIES THREE-SPEED TRANSAXLES H-SHIFT PATTERN WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

DISASSEMBLY 1. Position the shifter forks in neutral. 2. When disassembling the unit, it should be held so it lies on the case, and properly blocked so no weight rests on the input shaft or differential, but keeping the case rigid. The unit also needs to be held in a vice in such a way that it can be worked on without the chance of falling, or causing injury. 3. Oil seals have a double lip so seal sleeves do not offer much protection during removal. Upon reassembly new seals should be used. 4. Tap dowel pins into the case and remove socket head cap screws.

AXLE

OUTPUT GEAR

CASE

We caution you against the use of aftermarket variations of braking systems, adjustments and service of these components. Removing or altering factory installed parts my affect performance and could result in death or serious injury. WARNING

• Servicing the braking system will void your warranty. See your Authorized Tecumseh Servicing Dealer. GENERAL 1. The 1200 series transaxle has three forward speeds and one reverse.

THRUST WASHER SPACER

5. Lift the cover off of the case. Discard the gasket. Remove output gear and shaft. SHIFTING ASSEMBLY

AXLE SUPPORT TO CASE/COVER SEAL AXLE

HOUSING

BUSHINGS PRESS FIT

2. This series is not intended for use with ground engaging equipment. That is, it should not be used to pull plows, tillers or similar equipment. Care is to be used and common sense is expected in any situation where a severe strain will be placed on the axles. 1200 Housing, Bushing and Seal Assy. On the 1200 series, replace the seals after complete reassembly.

72

6. Remove the shifting assembly as one unit.

REVERSE IDLER GEAR SHAFT AND SPACER

INSPECTION AND REPAIR Inspection of the case and cover on the 1200 series may indicate the need for replacement of the axle housings. Use an arbor press to drive out the housing, and a protective piece of bar stock between the housing and press when replacing the housing. Press the housing in squarely until the flange seats against the case and cover. ASSEMBLY

INPUT SHAFT AND GEAR

7. Remove the reverse idler shaft, spacer and gear.

1. Install the input shaft in the case. Use a soft mallet to seat the shaft and gear completely. Binding can occur if the shaft is driven in only part way. 2. Install the differential assembly. The four cap screw heads should face away from the output gear or downward.

GEAR CLUSTER ASSEMBLY

BEVEL EDGE DOWN SPACER

BEVEL EDGE OF TOOTH TOWARD LARGE GEAR

8. Lift out the three gear cluster.

INPUT SHAFT AND GEAR

INPUT SHAFT DIFFERENTIAL

3. Install the three gear cluster, with the smallest gear facing up. NOTE

CHAMFER TOWARD BEARING

Bevels of the small and middle gears go down toward the large gear with the large gear bevel facing up. The short spacer goes between the large and middle gears. REVERSE IDLER GEAR SHAFT AND SPACER

OUTSIDE END OF INPUT SHAFT

9. Remove the input shaft, then the differential. NOTE Note what the relationship of the bolt heads are prior to removal of the assembly.

INPUT SHAFT AND GEAR

4. Position the reverse idler shaft in the unit; then install the gear and spacer. 73

LUBRICATION Use S.A.E. 90 E.P. oil in the transaxle. Fill units 1203, 1204, 1204-A, and 1205 thru 1208 with 3 pints (1420 ml) of oil. All other units, fill with 2 pints (946 ml)of oil. SQUEEZE TOP OF SHIFT RODS

5. Install the shifter assembly as a unit into the case. When installed correctly, the neutral square formed by the shifting forks should appear through the case opening for attaching the shift housing. Both shift gears should be out of mesh.

OUTPUT GEAR AXLE

CASE

THRUST WASHER SPACER

6. Install the output shaft, gear, spacer and thrust washer. 7. Position a new gasket on the cover mounting surface; then install the cover. 8. Align the cover with the dowel pin and secure with the socket head cap screw. Torque to 10 ft. lbs. (13.6 Nm). 9. Install the axle seals using a sleeve and driver. 10. Install the axle supports. Be sure the mounting pad position is correct before tightening down the cap screws to 13 ft. lbs. (17.7 Nm). 11. Install a new gasket and shift lever housing. Torque screws to 10 ft. lbs. (13.5 Nm). Be sure the shift lever is in the proper position to allow shifting.

74

CHAPTER 13. HYDROSTATIC GEAR REDUCTION DIFFERENTIALS 1300 SERIES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

EQUIPMENT MOUNTING HOLES

COVER BRAKE SHAFT

WARNING

GENERAL The 1300 series unit, is driven by a hydrostatic pump connected to the units case. The transmission function is accomplished by the hydrostatic controls.The Tecumseh/Peerless unit, therefore, only reduces input shaft speed to the differential and axle assembly.

OIL LEVEL PLUG

AXLE SUPPORT AXLE

CASE

DOWEL GASKET

2. Axle supports, pressed from the inside out, must be removed from the case and cover, similar to the method used in the 1200 series transaxle. REMOVE MOUNTING SCREWS (4)

INPUT 1 2

3

4 4

6

7

4

2

8

HYDROSTATIC UNIT

5

1

9

10 11

1234567-

12

14 13

Legend for the 1300 Oil Seal 8 - Axle Thrust Washer 9 - Axle Support Brakeshaft 10 - Bushing Needle Bearing 11 - Cover Output Gear 12 - Differential Gear Output Shaft 13 - Case Spacer 14 - Thrust Washer

3. To separate the hydrostatic unit from the 1300, support both parts, then remove the four mounting screws, and separate the parts. Drain the oil from the 1300 unit. Any hydrostatic repair must be done through the equipment brand dealer.

INPUT GEAR (DRIVEN)

DISASSEMBLY 1. Clean the exterior surfaces. Drain lubricant; then separate the gear reduction from the hydrostatic unit. Check axle shafts for rough edges and high spots. Due to the hardness of the shafts, a stone may be necessary to remove metal burrs. Check for any evidence of oil leakage at the gasket or bearing surfaces.

HYDROSTATIC UNIT MOUNTING HOLES

4. After removing the hydrostatic unit, inspect the surfaces and the gears from outside the unit.

75

REASSEMBLY

5. Remove the lockscrews and tap the dowel pins out of the cover. Lift off the cover and discard the gasket. 6. Lift out the brake shaft, gear, and thrust washers on each side of the gears. 7. Lift the output shaft, gear, spacer, and thrust washer from the case. At the same time, lift out the differential assembly. NOTE No thrust washer is located between the output shaft and the case. 8. To service the differential, refer to Chapter 18 on differentials. 9. To service bearings, refer to Chapter 22 on bearing service. 10. To separate axle supports from the case and cover, use an arbor or hydraulic press. A piece of bar stock should be used to protect the support from the ram of the press that you are using. INSPECTION AND REPAIR 1. Inspect the case and cover for cracks, stripped threads, marred sealing surfaces, and bearing condition. The cause of any oil leakage should be corrected and if parts cannot be repaired, replace them. 2. Check shafts and gears for worn or chipped teeth. Check bearing surfaces for scratches which might affect oil seal performance. Check for wear. 3. Check needle bearings and be sure the bearings are not corroded or rusty. Replace bearings if in a questionable condition. Check the quality of the seal around the needle bearings. 4. Check differential for rigidity. Wobble indicates wear. Refer to the Chapter on differentials for service. 76

1. When installing axle supports, be sure the case and cover alignment is true with the press. Press supports in until the flanged surfaces contact the case and cover. 2. Install the differential and output shaft simultaneously. Position the 3/4'’ (19.1 mm) I.D. gear spacer and thrust washer on the shaft. 3. Center one 3/4'’ (19.1 mm) I.D. thrust washer over the case needle bearings then install the brakeshaft gear, and another 1-1/8'’ (28.6 mm) I.D. thrust washer. 4. Position a new gasket on the mounting surface of the case, then install the cover. Align the cover and case by tapping dowel pins into the cover and secure with lockscrews torqued to 10 ft. lbs. (13.6 mm). 5. Install a new brakeshaft oil seal and axle using seal protector. 6. Install new axle support oil seals using a seal protector. 7. Add 2-3/4 pints (44 oz.) (1301 ml) Oil (S.A.E. EP 90) before securing the hydrostatic drive to the 1300 series unit. Clean the mounting surfaces and use a new gasket between the units. Torque the four mounting bolts to 90-100 inch pounds (10.211.3 Nm).

1300 SERIES HYDROSTATIC GEAR REDUCTION DIFFERENTIAL

LUBRICATION Oil Bath S.A.E. E.P. 90 oil Part No. 730229B

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

77

CHAPTER 14. 2300 SERIES FOUR-SPEED TRANSAXLES H-SHIFT PATTERN WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury.

INTERNAL QUAD RING SEAL USED AT THIS POINT

When shifting gears verify the clutch is operated. Failure to do so may cause premature transmission failure which could result in death or serious injury. WARNING

WARNING DO NOT shift on a hill or when carrying a heavy load. Shifting on a hill may cause premature transmission failure which could result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury. WARNING We caution you against the use of aftermarket variations of braking systems, adjustments and service of these components. Removing or altering factory installed parts my affect performance and could result in death or serious injury. • Servicing the braking system will void your warranty. See your Authorized Tecumseh Servicing Dealer.

ROLL OR DOWEL PIN

3 SOCKET HEAD Cap screws (TORQUE TO 10 FT. LBS. [13.6 Nm]) GASKET INPUT SHAFT

DISASSEMBLY CASE

SHIFTING FORKS IN NEUTRAL

COVER

1. Position the shifter forks in neutral before disassembly.

GENERAL The 2300 series transaxle is a four speed forward with one speed reverse transaxle. BRAKE SHAFT

COVER

AXLE

SHIFT LEVER

SCRIBE MARK (IF NECESSARY)

AXLE HOUSING

MOUNTING BOLTS

SHIFT LEVER HOUSING INPUT SHAFT

AXLE HOUSING I.D. TAG

CASE

MOUNTING PADS

2. Remove both axle housings, and use the exposed axle as a ram to separate the seal retainers from the case and cover. 3. When disassembling the rest of the unit, it should be held so that it lies on the cover, properly blocked up, so that no weight rests on the brake shaft. The cover should sit rigidly so that the removal of parts can be done in a systematic step by step procedure. Be sure it does not fall causing injury.

78

4. Oil seals are of the double lip type so sleeve protectors do not offer much protection when removing them. Upon replacement, new seals should be used.

AXLE INPUT SHAFT

BE SURE SEAL IS REMOVED

CASE

1/32" (.794 mm) THRUST WASHER

3-GEAR CLUSTER (8) SOCKET HEAD CAP SCREWS

COVER

DOWEL PIN

5. Tap dowel pins into the cover and remove the socket head cap screws. AXLE

BRAKE SHAFT

7. Remove thrust washer and three gear cluster from the brake shaft, noting whether the cluster has a sloppy fit. NOTE To service the cluster bushings, refer to Chapter 22 on bearing and bushing service. 8. Inspect gear teeth for wearing, chipping or breaks. Wear or chipping on the bevel area only, indicates shifting while the equipment is in motion.

INPUT SHAFT

CASE

TURN CW

450 1-1/2" TO 2" (38 - 50.8 mm)

COVER

6. To separate the case from the cover. Lift the case 1-1/2 to 2'’ (38-50.8 mm) above the cover. Tilt the case so that the shift rods will clear the edge. Rotate the case so the boss hidden inside will clear the gears, then lift it free of the differential.

REVERSE IDLER GEAR AND SHAFT

9. Remove the reverse idler gear, spacer and shaft from the boss in the cover. Note that the spacer goes between the gear and the cover, and the gear bevels go down. Excessive wear on teeth bevels indicates improper shifting technique.

79

1/32" (.794 mm) THICK 1" (19 mm) I.D. THRUST WASHER IDLER GEAR

SHIFTING ASSEMBLY

SPUR GEAR LOW GEAR SPUR

BRAKE SHAFT

10. Lift out the shifter assembly. Service of this unit is described in Chapter 21 on shifting assemblies. If it is evident that the shifter assembly needs no further teardown, place it aside intact in a clean place for servicing at a later time. 11. Remove the low gear and shaft, and splined spur gear. Separate the gear and shaft. Note there is no thrust washer between the gear and case. FOUR HEX BOLTS HEADS UP

AXLE AND DIFFERENTIAL ASSEMBLY

LOW GEAR SHAFT BEARING

OUTPUT GEAR AND SHAFT

SPACER BRAKE SHAFT

2-GEAR CLUSTER

12. Remove the two gear cluster and spacer from the brake shaft. 13. Lift the differential unit out of the cover. NOTE

IDLER GEAR CHAMFERED SIDE UP, AWAY FROM BEARING

15. Remove the brake shaft. NOTE The brake shaft idler separates from the shaft. If separated, be sure that when reassembled, the idler gear chamfers are away from the cover. DIFFERENTIAL LOW GEAR SHAFT BRAKE SHAFT BEARING CARRIER BEARING 1/32" (.794 mm) THICK BEARING 3/4" (19 mm) I.D. THRUST WASHER BETWEEN GEAR AND BEARING

OUTPUT SHAFT BEARING INPUT SHAFT AND GEAR (FLAT SIDE OF GEAR UP) *OUTPUT SHAFT BEARING

SHIFT LEVER OPENING SHIFTER ROD SOCKETS *SHIFTER SHAFT BEARING SHIFTER ROD SOCKETS

Service information appears in Chapter 18 on differentials. 1/16" (1.58 mm) THICK 15/16" (23.8 mm) I.D. THRUST WASHER

*BRAKE SHAFT BEARING

LOW GEAR SHAFT BEARING DIFFERENTIAL AND AXLE ASSEMBLY REMOVED

OUTPUT GEAR AND SHAFT

14. Remove the output shaft and gear and thrust washer from each end of the shaft. 80

MAGNETIC DRAIN PLUG *BEARING TO BE .015" - .020" (.381-.508 mm) BELOW THRUST SURFACE

REVERSE IDLER SHAFT BOSS

16. Remove the input shaft from the case by tapping with a non-metallic hammer.

INSPECTION AND REPAIR

ASSEMBLY

1. Gears.

BRAKE SHAFT BEARING LOW GEAR SHAFT BEARING

a. Check bevels for evidence of damage due to improper shifting. NOTE

DIFFERENTIAL CARRIER BEARING

1/32" (.794mm) THICK 3/4" (19mm) I.D. THRUST WASHER BETWEEN GEAR AND BEARING

Input power to Tecumseh/Peerless Transaxles must be stopped before shifting. b. Check face of teeth for wear. Large shiny areas indicate too much tooth contact and possible excessive wear. Replace gears that are damaged or show excessive wear. 2. Shafts and Axles. a. Check surfaces for rust, pitting, scratches or wear. b. Check keyways, splines, threads, and grooves for wear. Replace parts if worn or damaged beyond a refinished state. 3. Case and Cover.

LOW GEAR SHAFT BEARING INPUT SHAFT AND GEAR (FLAT SIDE OF GEAR UP)

SHIFTER ROD SOCKETS

SHIFT LEVER OPENING

1. Install the input shaft in the case. Use a soft mallet to seat the shaft and gear completely. Often, binding in the assembled unit can be traced to a partially installed input shaft. 1/32" (.794 mm) THICK, 1" (25.4 mm) I.D. THRUST WASHER UNDER IDLER GEAR

Check for cracks, stripped threads, metal chips, flat sealing surfaces and rust. Clean out any rust. Replace parts if any damage is found that cannot be repaired. 4. Thrust Washers and Spacers. Check for shiny surfaces which indicate wear and replace if evident. Try to determine the cause of thrust washer wear such as lack of end play due to the reuse of an old gasket, or use of the wrong thrust washer. 5. Shifting Assembly. Refer to Chapter 21on shifting assemblies. 6. Gaskets. Replace all gaskets. 7. Oil Seals. It is a good habit to replace all seals. It is necessary to replace all double lip seals. See Chapter 1, for the paragraph on “OIL LEAKS, SEAL AND GASKET SERVICE”.

BRAKE SHAFT

IDLER GEAR CHAMFERED SIDE UP, AWAY FROM BEARING

2. Center one 1/32'’ (794 mm) thick by 1'’ (25.4 mm) I.D. thrust washer on the cover brake shaft needle bearing, then install the brake shaft and gear, (with the chamfer side away from the cover). 1/16" (1.59 mm) THICK, 15/16" (23.8 mm) I.D. THRUST WASHER

8. Bearings and Bushings. Refer to Chapter 22 on bearings and bushings.

OUTPUT SHAFT AND GEAR OUTPUT SHAFT BEARING

3. Install the output shaft and gear after centering a 1/16" (1.59) thick by 15/16" (23.8 mm) I.D. thrust washer on each end of the shaft. 81

AXLE AND DIFFERENTIAL ASSEMBLY

FOUR HEX BOLTS HEADS UP

OUTPUT GEAR AND SHAFT

BEVELED EDGE LOW GEAR SHAFT BEARING

SPACER BRAKE SHAFT

2-GEAR CLUSTER

9. Install the reverse idler shaft, spacer and gear into the cover. The beveled side of the idler gear should be down into the cover.

4. Insert the differential assembly into the cover. Note that the four bolt heads should be facing away from the output gear.

BRAKE SHAFT

5. Install the two gear cluster and spacer on the brake shaft. 1/32" (.794 mm) THICK, 7/8" (19 mm) I.D. THRUST WASHER IN PLACE ON BEARING

SQUEEZE SHIFTER RODS TO HOLD SHIFTER ASSEMBLY TOGETHER

TWO GEAR CLUSTER AND SPACER

1/32" (.794 mm) THRUST WASHER

REVERSE IDLER SHAFT 3-GEAR CLUSTER

10. With the small gear of the three gear cluster toward the spacer, install the three gear cluster and another 1/32'’ (.794 mm) thick by 7/8'’ (19 mm) I.D. thrust washer on the brake shaft. AXLE INPUT SHAFT

LOW GEAR SHAFT

CASE

(B)

SPUR GEAR TURN CW

6. Install a 1/16'’ (1.59 mm) thick by 3/4'’ (19 mm) I.D. thrust washer, gear and low gear idler shaft in the cover. Do not put a thrust washer on the exposed end of this shaft. Be sure the small gear meshes with the larger gear of the two gear cluster. 7. Center one 1/32'’ (.794 mm) thick by 7/8'’ (19 mm) I.D. thrust washer on cover shifter shaft bearing. 8. Install the shifter assembly (as a unit) into the cover.

82

450 1-1/2" to 2" (38-51 mm)

COVER

11. Position the gasket on the cover sealing surface, then install the case over the differential shaft. Be sure the boss goes under the gears and the edge of the case goes over the shaft rods in the opposite manner from which it was removed.

12. Once in position, if the case hangs up 1/2" to 1'’ (12.7 - 25.4 mm) above the cover, turn the input shaft to get the gears to mesh. The case should drop to about 1/4'’ (6.3 mm) from closing.

16. Upon installation of the axle housing, be sure mounting pads face in the same direction as when removed. Install cap screws and torque to 13 ft. lbs.(17.6 Nm). 17. Install the shift lever housing and new gasket.

CASE

INTERNAL QUAD RING SEAL USED AT THIS POINT

ROLL OR DOWEL PIN

3 SOCKET HEAD CAP SCREWS (TORQUE TO 10 FT. LBS. [13.6 Nm])

SHIFTING FORKS IN NEUTRAL

COVER INPUT SHAFT

13. Use a pair of needle nose pliers on the shifter stop on each shifter fork to agitate the shifter rod ends into their machined recesses in the case. 14. Align the case and cover with the two dowel pins, then install and tighten the eight socket head cap screws. Torque screws to 10 ft. lbs. Unit can now be placed flat on the work bench. NOTE

GASKET

TESTING AND LUBRICATION 1. For testing, refer to Chapter 1, page 6. 2. For proper lubrication type and amount, refer to Chapter 1.

Seal protectors must be used, when installing a seal over the axle ends or any shaft with a machined keyway.

OIL SEAL PROTECTOR (USE DURING ASSEMBLY) AXLE OIL SEAL

BRAKE SHAFT

OIL SEAL RETAINER

"O" RING

THRUST BEARING ASSEMBLY

15. Install new “O” rings and oil seals using the seal protector as shown. NOTE Coating both the "O" ring and seal with lubricant will help ease assembly. 83

2300 SERIES TRANSAXLES

LUBRICATION Oil Bath 64 oz. (1892 ml) S.A.E. E.P. 90 oil to be filled through shift lever opening Part No. 730229B

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

84

CHAPTER 15. 2400 SERIES HYDRO POWERED TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

3. After the coupling is installed over the driveshaft of the hydrostatic pump press the parts together. Secure the assembly with three socket head cap screws, torqued to the standard for the bolt being used. VEHICLE MOUNTING HOLES

HYDROSTATIC UNIT MOUNTING HOLES

COVER BRAKE SHAFT (RIGHT SIDE HERE)

INPUT SHAFT (LEFT SIDE HERE) AXLE SUPPORT RETAINING BOLTS

The 2400 Series transaxle is a gear reduction unit which is powered by a hydrostatic pump. SEPARATING AND COMBINING THE HYDROSTATIC PUMP AND THE 2400 SERIES TRANSAXLE. The two parts, gear reduction unit and pump, should be removed from the vehicle together.

LONG AXLE SUPPORT CASE HYDROSTATIC UNIT MOUNTING HOLE

SHORT AXLE SUPPORT

PRIOR TO REMOVAL, NOTE POSITION OF MOUNTING PAD IN RELATION TO UNIT. (ALSO NOTE SIDE TO WHICH SHORT SUPPORT AND LONG SUPPORT ATTACH).

DISASSEMBLY 4. Clean axles of burrs, rust and sharp edges. 5. Remove axle supports. Be sure to note in what position and to which side they attach. 6. Drain the oil from unit. Remove the seal retainers and “O” rings. MOUNTING SCREWS (3)

1. To separate the units, block the assembly in a protective vise, then remove the three hydrostatic mounting screws. Separate one unit from the other. If any binding occurs, remember that the drive shafts are held in common rotation by a splined coupling which will bind if the relationship between the input shaft and the pump is not straight. COAT INSIDE OF COLLAR WITH E.P. LITHIUM GREASE

7. Remove the eight socket head cap screws securing the case to the cover. Drive dowel pins out of case into cover, then lift case off of the cover. DIFFERENTIAL UNIT (NOTE POSITION OF CAP SCREW HEAD. REASSEMBLE IN COVER SAME WAY).

MOUNTING SCREWS (3)

DIFFERENTIAL DRIVE PINION AND GEAR (OUTPUT) DOWEL PIN COVER

INPUT SHAFT

DRAIN PLUG

BRAKE SHAFT AND GEAR

NOTE For service to the hydrostatic pump, it must be returned to the dealer who sold the vehicle for his service arrangement. 2. To combine the hydrostatic pump and the 2400 transaxle, coat the splined coupling with E.P. Lithium grease, and install it on the 2400 input driveshaft.

DOWEL PIN

FILL LEVEL PLUG

8. Before removing the differential unit, note the position of the cap screw heads. Replace the unit in the same way to insure axle lengths will be correct when installing the axle supports. 85

OUTPUT PINION, GEAR AND THRUST WASHERS BRAKE SHAFT GEAR, SHAFT AND THRUST WASHERS

INPUT SHAFT, GEAR AND THRUST WASHERS

OUTPUT SHAFT BRAKE SHAFT SPACER

INPUT SHAFT

COVER

9. Remove the input shaft and gear assembly. Note that thrust washers are on both ends of the shaft. 10. Remove the output pinion and the gear splined to it. Note the position of thrust washers on each end of the pinion. 11. To remove the brake shaft, the shaft must be tapped from the gear splined to it. Use a soft hammer. Note that both ends of the shaft have thrust washers. INSPECTION AND REPAIR 1. Clean all parts and examine for wear or damage. 2. Refer to Chapter 18 on differentials for service when working on differentials. Refer to Chapter 22 on bearing and bushing service to replace any loose or worn bearings. 3. Remove and discard oil seals from the input and brake shafts. Check axle seals and replace if any evidence of leaking exists. If protective seal sleeves were not used when removing seals and retainer assemblies, replace seals after assembly. Use seal protectors and correct drivers. See the paragraph in Chapter 1 “OIL LEAKS, SEAL AND GASKET SERVICE” for service. 4. Clean the case and cover. Protect the bearings from dirt. Lubricate the bearings to prevent rusting. ASSEMBLY 1. Install thrust washer in the cover for input, output and brake shafts. 2. Install the brake shaft into the gear in the cover. 3. Install the input and output shafts (with gear) and position spacers on the brake shaft. Install thrust washers on all shafts.

COVER THRUST WASHER INPUT SEAL BRAKE THRUST WASHER OUTPUT

4. Install the differential unit with cap screw facing down. 5. Position a new gasket on slightly raised dowels and install the case. Turn down eight (8) socket head cap screws lightly. Tap dowel pins in and tighten the cap screws to 10 ft. lbs. (13.6 Nm). 6. Use a seal protector and install the seal and retainer assemblies. Position a new “O” ring on the seal retainer. Be sure the mounting pad is in the correct position. Install each axle support and bolt down. Torque the cap screws to 13 ft. lbs. (13.7 Nm). 7. Using the proper seal protector and driver, replace the input and brake shaft seals. 8. Rotate shafts to check for binding or noise. 9. Add lubricant (2 pints [946 ml] S.A.E. EP90 oil) to level of the fill plug with the unit in normal mounted position. CASE THRUST WASHER SPLINED COUPLING SEAL THRUST WASHER "O" RING SEAL RETAINER

NOTE POSITION OF CAP SCREW HEADS

SEAL

86

NOTE POSITION OF AXLE SUPPORT SEALED BALL BEARING NOTE, EQUAL LENGTH AXLE EXTENSION FROM EACH SUPPORT

2400 SERIES HYDRO POWERED TRANSAXLES

LUBRICATION Oil Bath 32 oz. (946 ml) S.A.E. E.P. Part No. 730229B

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

87

CHAPTER 16. 2500 SERIES HYDRO POWERED TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

3. Clean all exterior surfaces of the transaxle. 4. Remove the axle supports. If supports are different or if there is a chance for confused reassembly, scribe alignment marks. TIMKEN® THRUST ROLLER BEARING

"O" RING SEAL

GEAR REDUCTION AND DIFFERENTIAL UNIT GENERAL Most 2500 Series two speed gear boxes are run by an Eaton® Model 10 hydrostatic unit. Power for the hydrostat is supplied by an engine with up to an 18 H.P. rating. The unit has infinite forward and reverse speeds in both a high and low range. The 2500 series are shipped without lubrication. Original equipment manufacturers fill each gear case with lubricant when installing the 2500 in the equipment. Lubrication for the 2500 is 7 to 8 pts. (3.3 - 3.8 Lt) of SAE Type A automatic transmission fluid. DISASSEMBLY

5. Remove and discard square “O” ring seal. 6. If the tapered roller bearings are loose, remove them. 7. Position the unit with the cover up side; then remove the dowels and screws. Lift off the cover and discard the gasket. THRUST OR TABBED WASHERS

OUTPUT SHAFT AND GEAR

AXLE AND DIFFERENTIAL ASSEMBLY

1. Remove piping and hydrostatic unit as necessary to allow repair. 2. Although the unit should have been drained of lubrication, be aware that removal of the axle support will allow trapped oil to spill. NOTE An oil supply is blocked in the hydrostatic pump when not running, so upon reassembly hydrostatic charging is not necessary.

SHIFT ROD

NOTE Any attempt to service the hydrostatic pump should be done only upon authorization of Eaton or the equipment manufacturer. Tecumseh does not authorize repair or adjustment of the unit. DOWEL

INPUT DRIVEN BEVEL GEAR

AXLE SUPPORT

DOWEL

88

HIGH RANGE DRIVEN GEAR LOW RANGE DRIVEN GEAR

SNAP RING

FORK

BOLT HEADS AWAY FROM LARGE GEAR LOW RANGE DRIVEN GEAR HIGH RANGE DRIVEN GEAR

8. To remove the inside components, first remove the differential and then thrust washers.

SPRING

SETSCREW

Case and Cover

FORK

1. Check for leaks or cracks. 2. As necessary, replace needle bearings as described in Chapter 10. DETENT BALL, SPRING AND SETSCREW

SNAP RINGS

DETENT BALL

3. Do not replace brake shaft and shifter rod seals until the unit is reassembled. BEVELED SIDE OF GEAR TEETH

HIGH RANGE

BEVELED SIDE OF GEAR TEETH

LOW RANGE

BRAKESHAFT

THRUST SPACER

SHIFTER AND BRAKE SHAFT

RETAINING RING

THRUST OR TABBED WASHER

9. To remove the shifter rod and fork, the set screw, spring and detent ball should be removed from the outside of the case. THRUST WASHERS INPUT INPUT SHAFT BEVEL SPACER (Shown GEAR Assembled) BEVELED

HIGH RANGE TRANSMISSION GEAR

(ROUNDED) SIDES

OUTPUT PINION

SHIFTER FORK

SNAP RINGS (2) SHIFTER ROD

LOW RANGE GROOVE

HIGH RANGE GROOVE

NEUTRAL GROOVE

Shafts and Gears 1. Check teeth for wear, pitting or breakage. 2. Inspect bearing surfaces for smoothness. 3. Inspect gears and shafts for out-of-round. 4. Splines should allow a smooth fit. Rotate meshing parts for a better fit if binding seems excessive.

THRUST SPACER BEARING LOW RANGE TRANSMISSION GEAR

THRUST OR TABBED WASHER

SHIFTER FORK (PARTIALLY REMOVED) FORK NORMAL POSITION

INPUT SHAFT

HIGH RANGE GROOVE

10. Remove both the input and shifter gear and shaft assemblies, along with the shifter rod and fork. 11. Remove the input shaft and gear assembly.

NEUTRAL

LOW RANGE GROOVE

SNAP RINGS (SHARP SIDE OUT)

12. Remove the output shaft and gear. INSPECTION AND REPAIR Axle Supports 1. Check ball bearings and bearing races for wear, rust and ease of rotation. Clean the interior of the support if necessary. 2. Replace the oil seals in the axle supports. 3. Check for cracks in the support.

Shifter Mechanism 1. Check spring for tension and ball for wear. 2. Check shifter rod grooves for wear. Be sure the sharp edge of the snap ring goes away from shifter fork. 3. Inspect the shifter fork for straightness and wear.

89

Differential

ASSEMBLY Install parts reversing the disassembly procedure. Be careful of the following: SETSCREW SPRING

DETENT BALL

AXLE AND DIFFERENTIAL ASSEMBLY PINION

SNAP RINGS

FORK

DETENT BALL, SPRING AND SETSCREW

BRAKESHAFT

RETAINING RING

CORE BODY

AXLE AXLE DRIVE GEAR LIMITED SLIP DIFFERENTIAL

1. Make sure you have all parts are present. 2. Check the snap rings for their condition.

1. After the shifter rod is positioned, install the detent ball, spring and setscrew. Slowly turn the setscrew inward while raising and lowering the rod until the detent ball stops the rod movement. 2. Be sure that thrust washers and spacers are between every shaft and the case and cover. 3. Threads of the differential bolts must be coated with standard stud Loctite. The bolt heads on the differential are up when installed. 4. Install a new gasket. It may be helpful to dampen the gasket with oil to get it to lie flat. 5. Use a seal protector to protect the axle support oil seals during installation.

THRUST WASHER COUNTER RETAINER BORE FOR RING

AXLE (SPLINED END)

AXLE DRIVE GEAR

AFTER ASSEMBLY 1. To install the brake shaft oil seal using a seal protector. 2. To install the shifter rod oil seal, use seal sleeve 670206 and driver 670211.

RETAINING RING

Other 1. Check thrust washers for wear. 2. Check tapered roller bearings for wear and ease of rotation. 3. Replace the shifter rod oil seal after assembly of all parts. 4. Check thrust bearing for wear. Replace any parts necessary. 90

6. Install axle supports correctly. Do not rotate the support to a new position when pressed tight against the square “O” ring seal or the seal may be cut.

3. Lubrication for all models is 7 to 8 pints (3.3 - 3.8 Lt) of S.A.E. Type A automatic transmission fluid. When filling, allow the fluid to settle behind the tapered bearings into the axle supports. This may necessitate filling, checking and adding. The oil fill hole is located in the case. If the shrouding on the equipment does not allow access to the oil fill hole when the 2500 is installed in the chassis, lubrication should be filled prior to installation in the equipment. If filling takes place before installing the 2500, orient the unit to a 90o angle to the axles. There should be no fluid leak. 4. Install the drive assembly according to the manufacturer’s instructions.

LOW RANGE TRANSMISSION DRIVE GEAR

HYDROSTATIC DRIVE MOUNTING SURFACE

DRIVEN INPUT GEAR

HIGH RANGE TRANSMISSION DRIVE GEAR

SPACER THRUST BEARING

SPACER OR SHOULDER

INPUT SHAFT

THRUST WASHER

TABBED THRUST WASHER

SHIFTER AND BRAKE SHAFT

OIL SEAL BEVELED SIDES OF GEARS OUTPUT SHAFT

TABBED THRUST WASHER THRUST WASHER

TABBED THRUST WASHER THRUST WASHER

SEAL

BALL BEARINGS (2) "O" RING SEAL ROLLER BEARINGS (2)

NOTE: NO BEARING AT THESE POINTS

NEEDLE BEARINGS (2)

91

2500 SERIES TRANSAXLES

LUBRICATION Part No. 730229B Refer to O.E.M. manual for type of lubrication.

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

92

CHAPTER 17. 2600 SERIES HYDRO POWERED TRANSAXLES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

5. To remove axle out of its support, tap lightly with a mallet from the inside out. A pressed-on sealed bearing will be on the end of axle. 6. Position the unit with the cover side up. Then remove the dowels and screws. Lift the cover off, and discard the gasket. DIFFERENTIAL INPUT SHAFT SHIFTER SHAFT SHIFTER GEAR CLUSTER

GENERAL The 2600 series transaxle has infinite forward and reverse speeds. It is powered by a Sundstrand ® hydrostatic drive connected to an engine with up to a 20 Horsepower rating. The 2600 series are shipped without lubrication from Tecumseh/Peerless. Original equipment manufacturers fill each gear case with lubricant when installing the 2600 in the equipment. Lubrication for the 2600 is 7 to 8 pts. (3.3 - 3.8 Lt) SAE Type A automatic transmission fluid.

OUTPUT SHAFT Dual Range with Lock Differential INPUT SHAFT DIFFERENTIAL

COUNTER SHAFT

DISASSEMBLY 1. Remove the hydrostatic pump as necessary to allow repair.

OUTPUT SHAFT Single Range without Lock Differential

NOTE An oil supply is blocked in the hydrostatic pump when not running so upon reassembly, hydrostatic charging is not necessary.

There are two different 2600 models as shown above. SPACER

2. Although the unit should have been drained of lubrication, be aware that upon removal of the axle support, the axle will be removed as well. This will allow trapped oil to spill.

THRUST BEARING

NOTE Any attempt to service the hydrostatic pump will be done only upon the authorization of Sundstrand® or the equipment manufacturer. Tecumseh does not authorize repair or adjustments.

INPUT SHAFT

THRUST WASHERS

3. Clean all exterior surfaces before disassembly. 4. Scribe alignment marks on the unit before removal to assist in reassembly. Remove the axle supports.

ALIGNMENT SLEEVES WILL BE PRESENT BETWEEN AXLE SUPPORT AND UNIT

COUNTER SHAFT

I.D. TAG

7. To remove components from the single speed version, first remove the differential, thrust washers, drive gear, input shaft, countershaft, output gear and shaft.

93

8. To remove components from the 2 speed with locking differential version, remove the shifter rod and fork, the outside bolt, spring and detent ball. Next remove the high range gear; then the shifter gear cluster and fork assembly together.

4. Splines should allow a smooth fit. Rotate meshing parts for a better fit if binding seems excessive. Shifter Mechanism (Dual Range).

BOLT, SPRING AND BALL DIFFERENTIAL LOCK FORK ASSEMBLY

HI-LOW SHIFT FORK AND ROD

1. Check spring for tension and ball for wear. 9. Remove the input shaft assembly. HIGH RANGE GEAR

THRUST WASHERS

2. Check shifter rod grooves for wear. Be sure snap ring sharp edges goes away from shifter fork on both shifter shafts. 3. Inspect shifter fork for straightness and wear. Differential 1. Make sure you have all parts. 2. Check thrust washers for wear.

INPUT SHAFT

LOW RANGE GEAR

THRUST BEARING SPACER

LOCK COLLAR AND PIN ASSY.

BALL BEARING

10. Remove shifter shaft, output shaft and the output gear in this order. 11. Remove differential and lock fork assembly together. INSPECTION AND REPAIR Axle Supports. 1. Check the roller bearings on the axles. Clean and remove any rust. 2. Clean the axle supports and inspect.

LOCK DIFFERENTIAL

NON-LOCK DIFFERENTIAL

3. Check differential lock collar for fork or pin wear.

Case and Cover.

4. Check ball bearings for ease of rotation. Replace any parts if necessary.

1. Check for leaks or cracks.

ASSEMBLY

2. Replace all oil seals. As necessary, replace needle bearings as described in Chapter 22 on bearing service.

Install parts reversing the disassembly procedure. Be careful of the following:

3. Do not replace brake shaft seal, brake shaft, shifter rod and shifter differential lock seals until the unit is reassembled. Shafts and Gears. 1. Check teeth for wear, pitting or breakage. 2. Inspect bearing surfaces for smoothness. 3. Inspect gears and shafts for an out-of-round condition.

94

1. After the shifter rod is positioned, install the detent ball, spring and bolt. Turn the set bolt inward (dual speed) until it contacts the case. 2. Be sure that thrust washers and spacers are between every shaft and case and cover. 3. Threads of the differential bolts must be coated with standard stud Loctite. The bolt heads are up when installed. Refer to Chaper 18 on differentials. 4. Install a new gasket. It may be helpful to dampen the gasket with oil for easier installation.

5. To place axle assemblies into case and/or cover, grease axle spline ends heavily. Push the axle through the seal, using extreme caution when axle splines are going through the seal. NOTE If you do not have the proper seal protector spray axle with brake cleaner and when dry, place one layer of thin, clear packing tape around splines and keyways. Lubricate the exposed tape, and the seals will be protected when pushing the axles through. 6. After the unit is assembled install the brake shaft oil seal, using a seal protector/installer. 7. Install the shifter rod oil seal, using the seal protector 670206 and driver 670211. 8. Install the locking differential shifter rod oil seal, using the seal protector 670206 and installer 670211. 9. Lubrication for all models is 7 to 8 pints (3.3 - 3.8 Lt) of SAE Type A automatic transmission fluid.

95

2600 SERIES HYDRO POWERED TRANSAXLE SINGLE SPEED

LUBRICATION Part No. 730229B Refer to O.E.M. manual for type of lubrication.

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

96

2600 SERIES HYDRO POWERED TRANSAXLE TWO SPEED

LUBRICATION Part No. 730229B Refer to O.E.M. manual for type of lubrication.

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

97

CHAPTER 18. DIFFERENTIALS WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury.

100 SERIES DIFFERENTIAL SNAP RING

HOUSING AXLE

WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

HOUSING DRIVE PIN

THRUST WASHER PINION GEARS

4. Remove the snap ring, bevel gear and thrust washer. Slide the axle from the differential carrier housing.

GENERAL The differential assemblies of Tecumseh/Peerless units are grouped together in this section. Though there is little similarity between the 100, 600, 800 and remaining series units, they are grouped here because their function is the same. The differential assemblies for the 820, 1200, 1300, 2300 and 2400 series Peerless units are very similar. However, each must be assembled in its own way. By grouping them together, you will become more aware of differences in each unit.

NOTE Bushings are replaceable in the differential carrier housing. To replace bushing, use bushing tool 670204. ASSEMBLY 1. Slip the axle into the differential housing carrier. Place the thrust washer and bevel gear on the axle and secure with a snap ring. Make sure the flat side of the snap ring is away from the gear.

MODEL 100 DIFFERENTIAL

2. Place pinion gears and thrust washers on the drive pin and insert the assembly into either differential housing carrier.

DISASSEMBLY

3. Use 3 oz. (89 ml) of bentonite grease as a lubricant.

1. Clean the outside of the differential. Remove all keys, pins, etc. Remove all burrs from keyways and holes. Use a stone on hardened shafts.

4. Assemble the differential carrier housings and sprocket with 4 bolts and locknuts.

AXLE

NOTE No oil seals or gaskets are required in this unit. A few units use a gasket between the two housings and seals around the axles.

HOUSING

AXLE

If no gasket is present, seal the housing with Loctite 598 part number 788093 using a 1/8" (3.18 mm) bead. MODEL 600 DISASSEMBLY

SPROCKET LOCK NUTS (4)

NOTE

2. Remove four (4) locknuts, bolts and the sprocket. Separate the differential carrier housings.

Axles vary in length so make a sketch of which axle goes where. DRIVE PIN AXLE

AXLE

AXLE HOUSING

AXLE

PINION GEARS BEVEL GEAR

DRIVE PIN

3. Remove the drive pin, pinion gears and thrust washers as a unit. 98

ROLL PIN

1. Drive out the roll pin that secures the drive pin with a suitable punch.

DRIVE PIN AXLE

BEVEL PINIONS

3. Install the bevel pinions SIMULTANEOUSLY FROM OPPOSITE SIDES by rotating pinions in opposite directions while sliding into position in gear assembly. Check the alignment by inserting fingers into drive pin holes. If not aligned, the drive pin cannot be inserted. Remove and replace the bevel pinions as only one tooth out of position will cause misalignment.

AXLE

BEVEL GEARS

BEVEL GEARS AXLE

2. Remove the drive pin. BEVEL PINIONS BEVEL GEARS THRUST WASHERS AXLE

4. After aligning, insert thrust washers behind each pinion. Insert the drive pin and secure with a roll pin. BEVEL PINIONS

MODEL 800 DISASSEMBLY

THRUST WASHERS

3. Thrust washers must be removed before attempting to remove the pinions. Remove the bevel pinions simultaneously by rotating the gears in the opposite direction; the gears will move out of position.

1. Same as disassembly for model 600, except for additional parts on the axle. 2. Remove and inspect seals, bearings and washers for wear; replace if necessary. 3. If differential was disassembled note positioning of differing length axles so correct reassembly may be performed. REASSEMBLY 1. Reassemble in reverse order of disassembly.

SNAP RING CUP FACES OUT

SEAL

4. Remove snap ring, bevel gear and thrust washer. Slide the axle out.

BEARING WASHERS

CUP FACES OUT

SEAL

BEARING

5. Inspect the bushings and gears for wear and replace when necessary. REASSEMBLY OF DIFFERENTIAL ASSEMBLY 1. Place axles (left and right) into differential gear assembly. Install thrust washers. 2. Place the bevel gears on the shaft and install the snap ring in the groove on the shaft.

BEARING (NEEDLE TYPE)

BEARING (NEEDLE TYPE)

2. Install seal cup end out from the center of the differential to prevent dirt entry.

99

OLD STYLE

SQUARE CUT "O" RING

"A"

"C"

MST SERIES DIFFERENTIAL This unit is similar to the 900, except it uses no bearing blocks. The differential is supported by the shoulders on the ring gear. CAST IRON DIFFERENTIALS USED IN TECUMSEH/ PEERLESS TRANSAXLES

SEAL NEW STYLE "B"

RING GEAR

DIFFERENTIAL

"D" HEAVY DUTY SEALED BALL BEARING

SEAL

The 800 Series has used four styles of axle bearings. The earliest style “A” was a smaller loose cage needle bearing and must have the seal to the outside of that bearing. Style “B” must have the seal to the outside of the bearing. When bearing style “C” is used, a square cut “O” ring must be used on each side of the bearing. Bearing style “D” is a sealed ball bearing used in Heavy Duty applications. Styles “B”, “C” and “D” are interchangeable. Needle bearings A, B, and C must be repacked with E.P. Lithium grease. NOTE

BEARING SURFACE

HEX HEAD BOLT

NOTE The models covered are the 820, 1200, 1300, 1700, 2000, 2300 and 2400 series. The differential construction may vary from the illustrations but is basically similar. FOUR RETAINING BOLTS

SNAP RING RETAINER

Needle bearings are lubricated with E.P. grease. DO NOT USE BENTONITE on needle bearings. For maximum gear train life use only Bentonite grease on all shafts and gears, Tecumseh part number 788067C.

65

4

MODELS 900, 910, 915, 920 and 930

1 7

2 3

DIFFERENTIAL This style differential is supported by the case and cover with thrust load being absorbed by either bearing blocks or a bearing strap as shown. Both types use thrust washers on the axle bevel gears. DIFFERENTIAL ASSEMBLY BEARING STRAP DIFFERENTIAL BULL GEAR

BEARING BLOCKS BEVEL GEAR

AXLE

BEVEL PINIONS

WASHER 2 SNAP RINGS RING GEAR

Ensure you have all of the parts as the unit is assembled in your hands and placed directly into the case. 100

8

DIFFERENTIAL CARRIER WITH THREADED BOLT HOLES DIFFERENTIAL GEAR

PINION GEAR DRIVE BLOCK DRIVE PIN

The 1200 series differential carrier is supported directly on the axle (1). Roller thrust bearings (2) are used between the bevel gear (3) and the differential carrier (4). This illustration shows axles with snap ring (5) retainers; some earlier production had rolled over axle ends to secure the assembly. Thrust washers (6) are used at the ends of the differential carriers and the case/cover thrust face. The drive pin (7) and drive blocks (8) are similar to those used on the 1700 series. Replace the differential carrier if worn in excess of .878 (22.3 mm) at point A.

2

RING GEAR

THRU BOLT HOLES DRIVE PIN

POINT A

3

b 1

DRIVE BLOCKS

The 2000 series, three speed and the 2300 series, four speed differential will be discussed in this section. Examine the external bearing race on the differential carriers (1) for wear or pitting. Replace if necessary. The differential carriers in this assembly have replaceable bushings (2). Replace if worn in excess of .878" (22.3 mm) at point A. See Chapter 22 on Bearing and Bushing Service. These differentials have been built with rolled axle ends and also snap rings (3), as illustrated.

TWO PINIONS

5. If a snap ring is used, the axle assembly may be disassembled. If the axle end has been rolled, do not attempt to break the rolled retaining edge. The parts are to be replaced as an assembly. RING GEAR

SNAP RING AXLE END

DISASSEMBLY 1. Clean the differential assembly, then check and note the axle lengths and their relation to the heads of the four hex screw bolts. 2. If the unit will not turn freely, note where the unit binds. Check and replace those parts. FOUR HEX HEAD BOLTS

RING GEAR

THRUST WASHER

DRIVE BLOCK SEAT

6. Remove the snap ring and the thrust washer. Separate the bevel gear and the differential carrier from the axle. INSPECTION 1. See Chapter 22 on Bearing and Bushing Service.

BEARING RACE DIFFERENTIAL CARRIER

3. Place the differential in a large vise with soft jaws (hex head bolts up). Do not clamp the vise on the bearing race of a differential carrier.

2. Examine the gears for wear, cracked or chipped teeth. Check the internal splines of the gears and axle if the gear is removable. If excess play is noted, it may be necessary to replace the individual parts or both the gear and axle. 3. Examine the drive pinions, drive pins and drive blocks for wear and damage. Replace the pinion or the drive pin if excessively worn.

4. Remove the four hex head bolts, the upper axle and differential carrier. Remove the drive blocks, pinions, drive pin and thrust spacer if used, by lifting them out of the ring gear. Tap the ring gear lightly with a mallet to loosen them from the differential carrier.

101

SNAP RING

HOLES THREADED IN ONLY ONE DIFFERENTIAL CARRIER

BEVEL GEAR DIFFERENTIAL CARRIER RING GEAR REMOVED

THRUST WASHER

TESTING 1. Test the differential action by holding the upper axle vertically, and spinning the differential. The unit should spin and rotate freely. Place the assembly on the bench and rotate both axles in different directions. If any binding is noted in either test, check retaining bolt torque, gear meshing, or bearing surfaces in the differential carriers. Little or no play should be apparent between the axles and carriers. DUO-TRAK (Illinois tool works)* DIFFERENTIAL OPERATION

4. Examine the differential carriers. One has threaded holes and the other has larger holes so the bolts will pass through. Be sure to order the correct replacement parts. 5. Examine the internal bearing diameter of the differential carriers. SERRATED AXLE END

A cylindrical spring in the center of the unit presses the ten pinion gears against their pockets setting up a resistance to rotation. This resistance serves to lock up the gears in the differential until a moderate tractive difference in the wheels causes the resistance to be overcome. At this time the unit will act similar to a regular differential. The break away occurs when the equipment is turning, but under different tractive effort situations, such as operation on wet grass or snow. The spring acts to transmit torque to the non-tractive wheel to move the equipment. DISASSEMBLY, INSPECTION AND REPAIR

DIFFERENTIAL CARRIER

ROLLER THRUST BEARING WITH ONE THRUST WASHER

6. When assembling thrust bearings, always place a hardened thrust washer on each side of the caged thrust rollers. Never use the caged thrust rollers without the thrust washers. REASSEMBLY 1. Oil all parts during reassembly. Select the correct axle for the side of the differential opposite the hex head bolts. If the wrong axle is used it will require complete teardown of the differential, or possibly the entire transaxle. 2. Clamp the axle, in a soft jaw vise (not the bearing or oil seal surfaces). The differential carrier with threaded holes is assembled to this axle. 3. Torque the four hex head bolts to 7 ft. lbs. (5.2 Nm).

102

Parts breakdown will be found on the next page. Remove the four through-bolts. Separate axle assemblies from the body cores. To disassemble the axles, remove the snap ring and retained parts. Be sure the flanged thrust washer goes toward hub end of the axle upon reassembly. Use a pair of large 90o tip snap ring pliers and remove the cylindrical spring putting tension on the ten pinion gears. Once the spring is removed, the gears can be removed. Separate the two body cores from the ring gear. ASSEMBLY Install the body cores to the ring gear so that the pockets in one core are out of alignment with pockets in other core. Reassemble the thrust washers, bearing, carrier and side gear to the axle and secure with the snap ring. Install the pinion gears on one side, then use the differential carrier and axle to hold them from falling out when the unit is turned over. The side gear must mesh with the flat pinion. Install pinions in the other side to mesh with the previously installed pinions. Insert the cylindrical spring with a pair of large 90o tipped snap ring pliers so that it bottoms on the side gear. All ten pinions should be in contact with the spring. Install the other axle and secure the assembly with four through bolts and torque to 7-10 ft. lbs. (5.2 - 13.6 Nm).

BODY CORES RING GEAR

PINION GEARS

SPRING (ONLY OLDER UNITS) SNAP RING "DUO-TRAK®"

*DUO-TRAK® is the trademark of a patented limited slip differential designed by Illinois Tool Works. The Model 2600 transaxle has the unique customer option of a semi-locked differential. This system acts like a locked differential until the torque at the axle exceeds 50-70 ft./lbs. (68 - 95.2 Nm). At this point it acts like a regular differential. Using the following procedure, you can check for proper condition of this optional unit used on a few 2600 models, but not on all units. 1. Lift the rear of the tractor up so both tires are off the ground. Rotate one tire while in neutral; the other tire should rotate in the same direction. If not, disassemble the unit. If it does proceed to step 2. 2. Lock one axle or wheel assembly so it can not turn. 3. Using a torque wrench and socket on the other axle, turn in a clockwise rotation noting the break away point. It should be between 50-70 ft. lbs. (68 - 95.2 Nm). 4. If the torque is low, you will need to split the ring gear and carrier. Remove any shim between the two halves. If you do not find a shim, you will need to replace the spacer block. (see Illustration) 5. Re-assemble and check for proper break away torque as listed above. Breakaway should not exceed 70 ft./lbs (95.2 Nm).

BELLEVILLE WASHER ORIENTATION

103

CHAPTER 19. DRIVES This chapter relates to service of all Right Angle and T-drives. It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury. WARNING

Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

DRIVE BEVEL GEAR

SNAP RINGS

WARNING

GENERAL 1. Prior to removing the assemblies, examine the following items that may have failed causing the right angle drives to appear inoperative. 2. Drive belts: Inspect for breaks, tension, oil or grease saturation and inoperative tightening devices. 3. Pulleys: Tighten retaining screws. Examine for sheared keys. 4. Mower blade clutches and breakaway devices; some blades have slip type clutches that may slip during operation which may cause the right angle drives to appear to be damaged. Shearing devices are also used to absorb a damaging impact load. Check and replace the clutch members or shearing devices prior to removal of the right angle drive if a failure is noted. 5. Loose blade retaining nuts; Check torque and tighten if required. FINNED COVER RIGHT ANGLE DRIVE When finned cover right angle drives are to be serviced because of lubricant leakage, it will be necessary to replace the ball bearings.

FINNED COVER DRIVEN BEVEL GEAR IN LOWER POSITION

OUTPUT SHAFT

3. Output shafts achieve a different rotation by mounting a gear at the top or bottom of the shaft. 1/2" (12.7 mm) TO 3/4" (19.1 mm) DIAMETER BOLT OUTPUT SHAFT BALL BEARING

MACHINE BOLT APPROXIMATELY 4" (10 cm) LONG HEX NUT

LARGE WASHER TO REST ON OUTER BEARING METAL PLATE TO PROTECT LOWER BEARING

INPUT SHAFT BEVEL GEAR

4. If the driven bevel gear is on the bottom, remove the snap ring on the output shaft and pull out the output shaft. 5. Remove the output shaft bearing by using a large machine bolt, washer and nut. SNAP RING

OUTPUT SHAFT AND BEARING

DISASSEMBLY 1. Scribe marks on the covers and shafts to ease in reassembly. 2. Remove the cover, gasket and the lubricant from the drive.

INPUT SHAFT

6. The input shaft bearing, input shaft and bevel gear may now be driven out of the housing. Press the bearing into housing to remove. 7. The top ball bearing in the blind end of the housing is removed by heating the housing on a hot plate and tapping the outside of the housing with a nonmetallic mallet. Another option is to simply load the bearing area with grease and tap the output shaft in the center of the bearing quickly with a hammer. It will pop the bearing out of its position.

104

NUT

WASHER

MOWER BLADE

APPLY SMALL AMOUNT OF GREASE BETWEEN NUT AND MOUNTING SURFACE

Clockwise LEFT HAND

8. Right angle drives with the driven bevel gear at the top will have to be disassembled as illustrated above. The output shaft is larger in diameter inside than outside. When the output shaft is pulled out, the bearing will also be removed. INSPECTION Clean all parts in a cleaning solvent. Examine for wear or damage and replace as needed. Use care when handling ball bearings. See Chapter 22, Bearing and Bushing Service.

Clockwise

Counter Clockwise RIGHT HAND

REASSEMBLY Assemble in reverse of the disassembly instructions. It is important that only ball bearings with snap rings be used for the input shaft and top output shaft bearing. Use a tool for driving in bearings. In the event bearing bore is tight in the housing, heat the housing on a hot plate. Place a steel plate on the hot plate and rest the housing on the steel plate. DO NOT OVERHEAT. Work rapidly after removing the housing from the hot plate. Use care to prevent burns.

Clockwise

LUBRICATION See Lubrication Chart in Chapter 1. Counter Clockwise RIGHT HAND Clockwise LEFT HAND

Clockwise

Clockwise

RIGHT ANGLE DRIVE ROTATION

105

SMOOTH COVER RIGHT ANGLE DRIVE

DISASSEMBLY 1. Scribe marks on the covers and shafts to aid in reassembly. BEARING AT INNER EDGE OF MACHINED SURFACE

GASKET

SEAL COVER

INPUT SHAFT BALL BEARING

2. Remove the cover, gasket and lubricant.

DRIVING BEVEL GEAR

INPUT SHAFT

SERVICE Leaking lubricant: Correct lubricant leakage by replacing the seals at the input and output shaft as described below. 1. Input shaft seal replacement: Remove four screws and the cover. Replace the seal by driving in squarely so that it is .040'’ to .050'’ (1.02 - 1.27 mm) below flush. Use tool 670293 to protect the seal when replacing the cover and seal assembly over the input shaft. Place the seal protector on the shaft and coat with oil. Slide the seal and cover over the sleeve. Tighten the seal retainer screws and remove the sleeve. SHEET METAL SCREW SEAL

OUTPUT SHAFT

3. If the unit is built with the bevel gear on the input shaft toward the cover, remove the snap ring from the groove of the input shaft. SNAP RING

OUTPUT SHAFT

HOLE IN SEAL

2. Output shaft seal replacement. Remove the seal by punching two small holes in the seal with an awl as close to the outer edge of the seal as possible and opposite each other. Use care when making holes in the seal so ball bearing underneath is not damaged. Do not use a drill. Insert sheet metal screws into the holes and pull on the screws to remove the seal. Long screws may be turned in until they contact the outer race of the ball bearing and turned to lift out the seal. Place seal protector 670293 on the shaft, lubricate generously with oil and slide on the seal. Drive the seal into the housing until it is flush with the bottom of the housing.

106

SNAP RING

4. Remove four screws and the cover/seal assembly. 5. Remove the seal at the output shaft. 6. Remove the snap ring on the output shaft and tap it with a mallet on the outside end to drive it and the inner ball bearing out of the housing. Remove the output end ball bearing by driving it out from the inside.

BEVEL GEAR

“T” DRIVE SERVICE 1. Before removing a “T” Drive from equipment, be sure to scribe marks at one mounting hole to ensure correct reassembly.

OUTPUT SHAFT

"T" DRIVE WITH DIFFERENT INPUT AND OUTPUT ENDS OF INPUT SHAFT DRIVE MODEL NUMBER BALL BEARING

7. Remove the input shaft from the ball bearing with an arbor press. Always support the inner race when removing and replacing the input shaft into the ball bearing. Use tool 670293 to support the inside ball bearing race. BLIND BEARING SNAP RING

DRIVEN BEVEL GEAR ON OUTPUT SHAFT

"T" DRIVE WITH IDENTICAL INPUT AND OUTPUT ENDS OF INPUT SHAFT

2. To disassemble “T” Drive, remove self-tapping screws and housing cover and clean grease from internal area. Note and mark near the gasket surface on the side where the beveled input gear is located. Switching the “T” 180o will result in the output shaft having the opposite rotation. WHEN THE INPUT END OF SHAFT IS ON THIS END THE OPPOSITE END IS THE OUTPUT BEARING CAP AND SEAL RETAINER INPUT SHAFT

8. The ball bearing that supports the inside end of the input shaft is removed by holding the housing in hand while tapping the housing sharply on the outside with a nonmetallic soft mallet behind the bearing. It may be necessary to heat the housing to remove this bearing. Be careful not to distort the case by overheating. INSPECTION Clean all parts in a cleaning solvent. Examine for wear or damage and replace parts as needed. Use care when handling ball bearings. See Chapter 22 on Bearing and Bushing Service. REASSEMBLY Assemble the unit in reverse of the disassembly. When building up the unit, it is important to install the correct input shaft and identify it with the correct cover. Use the identifying scribe marks to assemble parts correctly.

HOUSING

IF INPUT END OF SHAFT OTHER END IS OUTPUT END

OUTPUT SHAFT BEVEL GEAR INPUT SHAFT BEVEL GEAR

3. Remove cap screws and both retainer cap and seal assemblies. Separate and discard oil seals and gaskets. BEARINGS ARE SLIP FIT ON BOTH INNER AND OUTER RACES

LUBRICATION See the Lubrication Chart in Chapter 1.

4. Press input shaft ball bearings out of the housing with fingers. If they stick, tap lightly using a drift punch around the outer race. 107

9. Press shaft, bearing and gear assembly into the housing until outer bearing race bottoms in its retaining cavity. 10. Install the outer bearing and a new snap ring. USE THE PROPER SIZE SEAL PROTECTOR

HOLD GEAR WITH FINGERS, THEN TAP ON END OF SHAFT WITH MALLET TO SEPARATE

ALWAYS REPLACE OIL SEALS

5. Using a soft mallet, separate the input shaft and gear. A slight press fit holds a spline surface on the shaft in a spline of the gear. 6. Remove and discard the output shaft oil seal. TAKE CARE NOT TO SCRATCH THE SHAFT. Remove and discard the snap ring and tap the shaft into the housing using a nonmetallic mallet. REMOVE SNAP RING

TO REMOVE GEAR REMOVE SNAP RING

11. Install a new oil seal, using a seal protector sleeve part # 670293 and driver until the seal is flush with the housing. POSITION OIL SEAL THEN USE SEAL DRIVER TO SEAT SEAL SQUARELY TO THE PROPER DEPTH

TO ALLOW SHAFT AND BEARING TO DROP OUT OF HOUSING

USE THE PROPER SIZE SEAL PROTECTOR

TO REMOVE BEARING REMOVE GEAR, AND PRESS BEARING INNER RACE

7. If necessary, remove the snap ring to separate the gear and bearing from the shaft. Hold the gear and bearing in one hand and tap the end of the shaft vigorously with a soft mallet. Cleaning, Inspection and Repair 1. Clean all parts of grease, rust, or foreign material. 2. Dry all parts. Compressed air may be used on all parts EXCEPT BEARINGS. 3. Check bearings for smooth rotation, then lubricate. 4. Remove all burrs and scratches from shafts with a fine file or stone. 5. Check housing for cracks or pulled metal. 6. Replace all snap rings.

12. Position the input bevel gear in mesh with the output shaft bevel gear. Tap the input shaft into place with a nonmetallic mallet. Use one hand to hold the gear and shaft to dampen the blows from the mallet. Be sure gear is on the marked side of the housing. 13. Align the shaft and insert a ball bearing on each bearing surface by hand. 14. Install new seals in the retainer caps using a driver. 15. Using seal protector # 670293 over the shaft serrated ends; install new gaskets and the bearing cap. Tighten retaining cap screws to 8-11 ft. lbs. (27.3 14.7 Nm).

7. Replace all oil seals.

16. Lubrication: See the Lubrication Chart in Chapter 1.

8. If separated, install the inside ball bearing and bevel gear on the output shaft. Be careful of alignment. The use of a press is preferable to installing bearings and seals with a mallet.

17. Install the gasket and cover and secure with self tapping screws. Torque to 20-24 in. lbs. (2.3 - 2.7 Nm). 18. Align scribe marks and install “T” Drive on the equipment.

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CHAPTER 20. 1100 SERIES DRIVES WARNING It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or serious injury.

DISASSEMBLY SNAP RING SEAL

WARNING Use approved safety procedures with equipment for removal/ installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury.

SHAFT

GENERAL

CAGE

BEARING ASSEMBLY "O" RING GEAR

SNAP RING "O" RING

1. Scribe marks on the covers and shafts to aid in reassembly. I.D. TAG

MAIN HOUSING

RING "O" RING

2. Clean and check all shaft ends before removing the cap and cage assembly.

CAP

OPTIONAL VENT "O" RING RING

CAGE

CAGE

3. Remove the four input cage bolts and remove the input cage; the assembly will follow. The 1100 series angle drive is a heavy duty gear box used with larger equipment with horse power ratings up to 20 H.P. This unit is of cast iron construction for strength featuring tapered roller bearings for longer life. It can be configured wither as a right angle drive with right or left handed rotation, or a “T” drive. Reassembly is the reverse of the disassembly procedure.

4. To disassemble the input cage assembly, first remove the nut and washer that holds the large keyed gear onto the shaft. With an outside puller, if necessary, remove the gear. The roller bearings will be attached.

109

5. Remove bearing from gear by using a bearing splitter and puller.* 6. Remove the shaft out of the cage. Remove roller bearing with outside puller toward threaded side. * Then remove the snap ring.

10. Remove the snap ring. 11. On the other end, use the same puller and remove both the keyed gear and bearing at the same time. 12. Remove the snap ring.

*When roller bearings and races are removed with a bearing puller, discard and do not reuse.

SOFT PLUG

SNAP RINGS

7. To remove the races, simply tap out with a punch and hammer. The large snap ring will be left in the cage when all parts are removed.

13. To remove the 1-3/4'’ (44.5 mm) soft plug, simply tap it out of the case. Discard the old plug. 14. To remove races, simply tap the race out of the cap and pry the crush ring out. The other race can be tapped out with a punch and hammer. If the unit is not equipped with a plug, very carefully pry the race and crush ring out of cap and discard. INSPECTION

8. Remove the output cap and the assembly will follow. 9. To disassemble the output shaft assembly, first remove the bearing that is located under the cap on the shaft, by using an outside puller.*

NOTE Do not hook a puller on the snap ring.

110

Clean all parts in cleaning solvent. Examine for wear or damage and replace as needed.

REASSEMBLY

CRUSH RING

It’s very important when assembling this unit that you use all new seals and “O” rings.

WOODRUFF KEY

SNAP RINGS CAP

1. Following the scribe marks, press the keyed gear on if necessary, and replace the snap rings on the output shaft.

5. Before installing the cover, first install a new crush ring into the cover. Press a new race up to the crush ring. To properly set up the output shaft preload, place the shaft into the case, and place the cover over the shaft without the case/cover shim and “O” ring. Tighten the four bolts to a torque of 200 in. lbs. (22.6 Nm) at 50 inch pound (5.65 Nm) increments. 6. Now remove the cover and place a new case/cover shim with a new “O” ring and torque to 200 in lbs. (22.6 Nm) at 50 inch pound (5.65 Nm) increments. SOFT PLUG

2. Make sure the inner bearing race is used when pressing roller bearings into place. NOTE Service bearings for this unit may have a shim in the box along with a new outer race. When pressing the bearing next to the gear, place the shim for that bearing and race (if present) next to the gear first, then press in the race and bearing.

7. To install a 1-3/4'’ (44.5 mm) soft plug, tap in carefully with the lip up until 1/16'’ (.34 mm) below flush is achieved. "O" RING

BEARING RACE "O" RING

SNAP RING BEARING RACE

3. Install the other bearing that fits into the cap without the shim. 4. The race that is used with a roller bearing on the gear side mounts into the case. Press the race in carefully until seated.

CAGE

8. To assemble the cage assembly, place the large snap ring in its mounting area in the cage. Press the small race to the snap ring from the outside. 9. Press the large race into the cap.

NOTE Make sure that all races and roller bearings are kept together as provided.

111

WOODRUFF KEY

SNAP RING ROTATE CAGE WHILE TIGHTENING NUT

10. Place a small snap ring on the shaft. 11. Press a roller bearing on the shaft to the back side of the snap ring and do not use a shim. Install the woodruff key. GEAR

BEARING

SHIM IF REQUIRED

12. Press a large shim and a new large roller bearing onto the gear pressing on the inside bearing race.

"O" RING

14. To achieve a proper pre-load on the bearings, place the outboard side of shaft in a protected jawed vice. Begin to tighten the nut on the gear side, while turning the cage until a very slight drag is achieved. Tighten so the bearing in the cage housing does not have end play and the parts should spin freely. 15. After loading to the bearing is done, place a new “O” ring around the outer diameter of the cage and position it in the case. Reinstall bolts and tighten to a torque of 200 in. lbs. (22.6 Nm). 16. To install seals, use a 1'’ seal protector. Position seals so that they are installed .100" (2.5 mm) below flush. LUBRICATION After assembly, fill with 1 pt. (473 ml) E.P. 90 gear oil.

"O" RING

13. Place the shaft into the proper position in the cage, and place the gear with the bearing onto the shaft.

112

1100 SERIES DRIVE

LUBRICATION Oil Bath 16 oz. (473 ml) S.A.E. E.P. 90 Oil Part No. 730229B

The above illustration is supplied as a general assembly guide, your model may be different based on manufacturers requirements.

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CHAPTER 21. SHIFTING ASSEMBLY WARNING

It is recommended that you take special notice of all items discussed in this manual and wear the appropriate safety equipment. Failure to do so may result in death or

serious injury. Use approved safety procedures with equipment for removal/installation of axles, keyways and hardened shafts. Remove all burrs and sharp edges with a honing stone or crocus cloth before installation. Failure to do so could result in equipment damage, death or serious injury. WARNING

KEY SPRING HEIGHT To check shifting keys for loss of spring height, place the short flat portion of a key on a flat surface as shown, measure the distance from the surface to the key tip. The measurement should be from .400" to .460" (10.211.7 mm); if the measurement is below .400" (10.2 mm) the key should be replaced. VERTICAL INPUT .400 (10.2 mm) .460 (11.7 mm)

H-SHIFT PATTERNS

IN-LINE SHIFT PATTERN

HORIZONTAL INPUT H-SHIFT PATTERNS

600 SERIES

700 SERIES 800, 820 SERIES 900, 910, 915, 920, 930 SERIES MST SERIES (AVAILABLE IN 2 to 8 SPEEDS) FIGURE SHOWS 5 SPEED UNIT

LEFT HAND INPUT

RIGHT HAND INPUT

SHIFT LEVER ASSEMBLY 1700 SERIES 2000 SERIES

1200 SERIES 1700 SERIES 2000 SERIES

NO LEFT HAND INPUT 1200 SERIES 2300 SERIES

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2300 SERIES

GENERAL

REASSEMBLY

1. Prior to removing a shift lever assembly from a transaxle, make note of the position of the shift lever so that it may be assembled correctly to the shift lever housing.

1. DOWEL PIN TYPE. Secure with a new dowel pin. A second dowel pin is used in some assemblies for alignment. This dowel pin is located on the gasket surface of the shift lever housing and fits into a mating hole in the transaxle.

2

Move the shift lever to Neutral, if possible, before removing it from the transaxle. Clean around the lever housing to prevent dirt from falling into the transaxle. Cover this opening by inserting a clean rag with a screwdriver.

HANDLE END SHIFT LEVER

QUAD RING SEAL ROLL PIN

DISASSEMBLY

RETAINER

1. Place the shift lever in a vise so the shift lever housing is at least one inch from the top of the vise jaws.

QUAD RING SEAL

SNAP RING

SHIFT LEVER HOUSING

SHIFT LEVER

SHIFT LEVER ROLL PIN

2. SNAP RING TYPE. Secure parts with the snap ring. Before installing the shift lever and housing into the transaxle housing, ensure the shifting forks are in the neutral position. 3. Always use new gaskets between the shift lever housing and the transaxle.

SHIFT LEVER RETAINER

DOWEL PIN

SHIFTING ASSEMBLY GENERAL

2. DOWEL PIN STYLE. Locate the dowel pin holding the retainer in the housing from the outside. Place a 1/4'’ (6.3 mm) flat face punch on the gasket surface directly over the dowel pin. Strike the punch firmly with a hammer to dislodge the retainer from the shift lever housing. Always use a new dowel pin for reassembly. 3. SNAP RING STYLE. Use a snap ring pliers for removing the snap ring; loosen the vise and disassemble the pieces. 4. Remove the shift lever from the shift lever housing. Examine the roll pin in the ball of the shift lever. If bent or worn, replace. When inserting a new roll pin in the ball, position so equal lengths protrude from both sides of the ball. 5. Oil leakage past the point where the shift lever enters the shift lever housing will require replacement of the quad ring seal in the shift lever housing.

1. Differences in assemblies will be noted in the following servicing procedure. Always use the parts list for each model to obtain the correct parts. SHIFTER FORK

SHIFTER STOP SNAP RING

DETENT BALL AND SPRING

NEUTRAL GROOVE

DETENT BALL AND SPRING

SHIFTER ROD "A" SNAP RING

SHIFTER ROD "B" SHIFTER FORK NEUTRAL GROOVE

3 Stop, 3-Speed Transaxle Shifter Rod & Fork Assy.

Prior to reassembly, be sure the bends in the shift lever correspond to the mounting on the vehicle.

115

SHIFTER FORK

NEUTRAL GROOVE

SHIFTER STOP SNAP RING

INDEXING BALL AND SPRING

NEUTRAL GROOVE SHIFTER STOP

SHIFTER ROD "A"

SPRING

SNAP RING DETENT BALL

INDEXING BALL AND SPRING

SHIFTER ROD "B" SHIFTER FORK NEUTRAL GROOVE

4 Stop, 4-Speed Transaxle Shifter Rod & Fork Assy.

2. Shifting assemblies are removed from and installed into the transaxles by squeezing the top end of the shifter rods. This causes a binding that retains all parts during removal or installation. INSPECTION 1. Replace the shifter stop if worn or damaged. 2. Examine the teeth and the internal splines of the two shifter gears. Replace damaged gears. The gears must slide freely on the shifter shaft. Excessive wear of the internal spline of the gears will create cocking and difficult shifting. Replace the gear if this condition is present. 3. Replace the shifter shaft needle bearings if wear is evident. See Chapter 22 on bearings for removal. Replace if the bearing surface of this shaft should be scuffed, pitted or worn to a diameter less than .750'’ (19.1 mm).

SHIFTER FORK

3. Slide the shifter fork into the shifter rod until it lines up with the hole with the detent ball and spring. With a flat blade screw driver, press the detent ball into the hole and move the shifting fork completely onto the shifter rod. 4. Move the shifting fork to the neutral position. The neutral groove is the center groove. If the shifter rod has four grooves, the neutral groove is the second groove from the shortest end. This neutral groove can be seen through the hole in the shifter fork. SHIFTER RODS

SNAP RING ANNULAR GROOVE

4. Replace other parts showing wear, looseness, cracks, etc... DISASSEMBLY NEUTRAL POSITION

To disassemble the shifter and fork assembly, use the assembly procedure in reverse. ASSEMBLY 1. Reassemble the shifting assembly by following the illustrations. Lay the parts on the bench on a clean paper or shop cloth. Pay particular attention to the annular grooves in the shifter rods and snap rings. SHIFTER FORK

SHIFTER STOP SNAP RING

DETENT BALL AND SPRING

NEUTRAL GROOVE

DETENT BALL AND SPRING

SHIFTER ROD "A" SNAP RING

SHIFTER ROD "B" SHIFTER FORK NEUTRAL GROOVE

2. Assemble the shifter forks onto the shifter rods. The shifter forks are interchangeable. 116

SHIFTER FORKS ANNULAR GROOVE SHIFTER STOP

SNAP RING

5. When the shifter forks are properly assembled to the shifter rods and positioned in neutral, the ends of the notches in the shifter forks are in alignment.

Tecumseh Transmissions Shift Key Quick Reference Guide Service No.

Length

Where Used

Shape and Size (shown actual size)

792071

2.950" 7.493 cm

500s

792089A

2.625" 6.668 cm

700/800/801/910

792094

2.812" 7.142 cm

728/A/729/A/757/A/759/780/792

792018

3.165" 8.039 cm

900s

792123A

3.980" 10.109 cm

820/920/930

792136A

3.980" 10.109 cm

820/930/MST

792131

4.040" 10.262 cm

820-014/A

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CHAPTER 22. BEARING AND BUSHING SERVICE GENERAL BEARING AND BUSHING CARE

NEEDLE BEARING SERVICE

1. Bearings, bushings and bearing surfaces should be thoroughly cleaned prior to examination. Examine closely for scuffing, wear, pitting, and abnormal conditions. Replace if any of these conditions appear.

It is advisable to use an arbor press to remove and install needle bearings.

2. Use clean, filtered solvent to clean bearings. Then use a clean, lint free cloth to dry the bearings. Immediately coat the cleaned bearings with lubricant to prevent oxidation and corrosion. If the bearing is to be stored, wrap in oil proof paper until needed. 3. Take care of bearings in the case and cover. Cover them to keep out any foreign material. Place the gasket surface down on clean paper and cover with a clean cloth. Never clean the lubricant from new bearings. This lubricant prevents damage before the transaxle lubricant enters the bearing. BALL BEARING SERVICE The ball bearings used in the outer ends of the axle supports are sealed. Without removing the bearings, but with the axle removed, rotate the inner race with your fingers. If any roughness is noted, replace the ball bearing assembly. These ball bearings are factory lubricated and additional lubrication cannot be added. When driving in these ball bearings, use the proper tool that drives on the outer race as shown on the next page.

1. Use a bearing tool to press out the bearing. Insert the proper tool in the bearing, and with an arbor press, press out the bearing from the inside. 2. When installing open end needle bearings, always apply pressure to the stamped side. 3. Use only recommended tools to insert bearings. The opposite end of the same tool used for removal is used for replacement.

1. Install the needle and ball bearing combination for the input shaft into the cover prior to the installation of the input shaft.

2. Using a socket or bearing installer, install the input shaft ball bearing into the case by driving on the outer race. After the input shaft bearings are installed, assemble the input shaft. Press the input shaft into the bearing combination while supporting the inner race of the ball bearing on a hollow tube.

118

4. The inside face of the bearing housing should be below the thrust face on the case or cover. This distance is controlled by the design of the inserting tool. By using the proper tool, the bearing will be protected upon installation. Bearings should be pressed into the cover .015'’ to .020'’ (.381-.508 mm) below the thrust surface. The open end bearing in the low speed shaft of four speed transaxles is to be .010'’ (.254 mm) below the thrust surface. The open end bearing in the shifter shaft should be .010'’ (.254 mm) below the end as well.

9. Insert a 7/16'’ (.438 mm) metal rod into this bearing. With a mallet strike the rod sharply to compress the wet paper. Continue to add more wet paper, this will hydraulically lift the bearing out of the shaft. 5. To remove the needle bearing in the splined shifter shaft, proceed as follows:

10. Use the authorized tool listed below to install the new bearing. Needle bearings in shifter shafts should be installed .010'’ (.254 mm) below flush.

NOTE Blind bearing pullers are available to remove this bearing. There is a space between the bottom of the drilled hole and the inside end of the bearing to accommodate the ridges of the bearing puller. 6. With the needle bearing up, clamp the splined shifter shaft vertically in a soft jaw vise so the lower end of the shaft rests on a block of wood. 7. Prepare some pieces of paper toweling, newspaper, etc. by soaking in water. 8. Tear paper into pieces, approximately one to two inches square. Stuff these wet pieces of paper into the needle bearings until full. BUSHING SERVICE When removing bushings, use the combined bushing remover and installation tool. Position the piece to be serviced on the table of an arbor press with an opening to allow the bushing to pass through. 1. Use the proper tool as illustrated. 2. The bushings in the three gear cluster, four speed transaxle are both removed at the same time. The bushing from one end will contact the bushing in the opposite end and both may be pushed out. 3. Use an arbor press and push the steel ball through the new bushing to expand it to the required size.

670203

670209

670204

670234

670207A

670210

670213

670211

670252

670251

670206

670263 670205

PEERLESS TOOL KIT 670254A Tool No.

Description

Use with:

670203 670204 670205 670206 670207A 670209 670210 670211 670213 670234 670251 670252 670262A 670263

Oil Seal Installer Bushing Driver and Installer Bushing Driver and Installer Oil Seal Protector Bearing Driver and Installer Oil Seal Installer Bearing Driver and Installer Oil Seal Installer Bearing Driver and Installer Bearing Driver and Installer Bearing Installer Bearing Driver Oil Seal Protector Oil Seal Protector

Seal with 13/16" (20.64 mm) I.D. Bushing with 3/4" (19.05 mm) I.D. Busing with 1-1/2" (38.1 mm) I.D. Seal with 1/2" (12.7 mm) I.D. Bearing with 5/8" (15.87 mm) I.D. Seal with 21/32" (16.7 mm) I.D. Bearing with 1/2" (12.7mm) I.D. Seal with 1/2" (12.7 mm) I.D. Bearing with 9/16" (14.29 mm) I.D. Bearing with 5/8" (15.87 mm) I.D. Input Bearing on 800 Series Bearing with 11/16" (17.46 mm) I.D. - 800 Series All 3/4" (1.8 mm) Axle Shaft Seals Seal with 5/8" (15.87 mm) I.D.

119

CHAPTER 23. VST TROUBLESHOOTING The information on the following pages has been provided to help understand the internal operation of the VST. Do not use this information to attempt any internal repairs. Tecumseh's current policy on hydrostatic transaxles that have internal failures is to replace the complete unit. This has not changed. However, we would like to provide a failure checklist to assist in making an accurate evaluation of the complete tractor to eliminate any unnecessary replacements. Here is a list of items to check and corrective actions to take. To properly test the unit for power loss. 1. Allow the unit to cool before trying the following steps. 2. Put the shift lever in a position that is 1/2 (12.7 mm) of the travel distance from neutral to forward. 3. Place the tractor on a 17 degree grade. 4. Drive the tractor up the grade (without the mower deck engaged). The loss of power experienced should be approximately 20%. This is considered normal. If the loss of power is approximately 50%, this would be considered excessive. 5. Bring the unit to neutral, shift into forward and note the response. Care should be taken to move the lever slowly to avoid an abrupt wheel lift. To determine if the problem is with the hydro unit, all external problem possibilities must be eliminated. Here are some potential problem areas. 1. Overheating: Heat can cause a breakdown in the viscosity of the oil which reduces the pressure used to move the motor. Remove any grass, debris, or dirt buildup on the transaxle cover and/or between the cooling fins and fan. Buildup of material will reduce the cooling efficiency. 2. Belt slippage: A belt that is worn, stretched, or the wrong belt (too large or wide) can cause belt slippage. This condition may show the same loss of power symptom as overheating. Typically, the unit which has a slipping belt will exhibit a pulsating type motion of the mower. This can be verified visually by watching the belt and pulley relationship. If the belt is slipping, the belt will chatter or jump on the pulley. If the belt is good, a smooth rotation will be seen. Replace the belt and inspect the pulley for damage. 3. Leakage: The VST and 1800 Series have two oil reservoirs which can be checked for diagnostic purposes. The first is the pump and motor expansion bellows, With a small diameter blunt or round nose probe, check the bellows depth through the center vent hole. Proper depth from the edge of that hole is 3-1/4 - 3-1/2 inches (8.25 - 8.9 cm). The second chamber is for the output gears including the differential. FIRST make sure the tractor is level, then remove the drain/fill plug. NOTE: Some units that do not have differential disconnect will have two plugs. We recommend using only the primary plug. Insert a small pocket rule until you touch the bottom of the case. Remove it and check for 1/4 - 3/8 inches (6.5 - 9.5 mm) contact; this is full at its 8 oz. (236 ml) capacity.

120

4. Low ground speed: If the linkage is not synchronized to absolute neutral, or the shift lever is not properly fastened to the tapered control shaft, full forward travel may not be achieved. This may cause a false reading and be misdiagnosed as a low power condition. This also could be caused by the brake not releasing. To determine absolute neutral, the hole in the tapered control shaft must face straight up and down. At this point make sure the OEM linkage is in neutral. To properly fasten the control lever to the shaft, torque the nut to 25-35 ft. lbs. (34 - 48.3 Nm) with the shaft and the lever in neutral. When attaching the shifter arm to the shaft you must prevent any rotation during torquing. This can be done by placing a long 5/16" (7.94 mm) bolt in the hole as shown in illustration. Hold the bolt until the tapers are locked and the nut torque is correct. To make sure that the brake is not binding, drive the unit up a slight grade. Position the speed control lever into neutral. The unit should coast backwards. If the unit does not coast back slowly, the brake is not released from the brake disk. Adjust the brake linkage to release the brake completely when the foot pedal is released. 5. Hard to shift: Typically, hard to shift symptoms are not caused by the hydrostatic unit. The shift arm should move with relative ease. Check the ease of movement of the shift arm with a torque wrench. For the following spec numbers, the reading should be 40-65 inch lbs (4.5-7.34 mm). measured at the end of the shaft (205-006, 016, 021, 022, 030, 033, 036, 040, 046). If the model has a neutral spring, the torque reading should be 70-150 inch lbs. (7.9-16.9 mm). All other models (without neutral return spring) should read 150 - 120 inch lbs. (13.5-16.9 mm) measured at the end of the shaft. Binding may occur in the linkage connections due to rust or moisture. Lubricating these connections and checking for bent or damaged parts should resolve hard shifting.

PRODUCT CONTAINS PATENTED FEATURES 90o from case/cover parting line is 90 o neutral Parting Line DIRECTION CONTROL SHAFT DIRECTION CONTROL LEVER

POCKET RULE FOR OIL CHECK

PUSH NUT SQUARE CUT "O" RING

3/8" (9.53 mm) 1/4" (6.35 mm)

DIFFERENTIAL DISCONNECT HOOKUP 3¼" (82.5 mm) 3½" (88.9 mm)

EXPANSION BELLOW'S CHECK COLD FOR CORRECT DEPTH

NOTE: The above illustration is of a foot control unit with differential disconnect. Consult your parts list by model and specification number to get correct parts for your unit. ALL PARTS SHOWN MAY NOT BE ON YOUR UNIT.

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TECUMSEH T E C H N I C I A N ' S

H A N D B O O K

This manual covers the following models: VH80, VH100, HH80, HH100, HH120, OH120-180 Model numbers are located on the engine shroud. Other illustrated Tecumseh 2-Cycle Engine, 4-Cycle Engine and Transmission manuals; booklets; and wall charts are available through Tecumseh. For complete listing write or call

8 TO 18 HP CAST IRON FOUR CYCLE ENGINES

Contents Page CHAPTER 1. GENERAL INFORMATION ................................................................................................................................... 1 SECTION 1. ENGINE IDENTIFICATION ............................................................................................................................. 1 SECTION 2. ENGINE CARE ............................................................................................................................................... 2 CHAPTER 2. AIR CLEANERS, CARBURETORS, GOVERNORS AND LINKAGE ................................................................... 4 SECTION 1. AIR CLEANERS .............................................................................................................................................. 4 SECTION 2. GENERAL CARBURETOR INFORMATION .................................................................................................. 5 SECTION 3. TECUMSEH CARBURETORS ....................................................................................................................... 6 SECTION 4. WALBRO CARBURETORS .......................................................................................................................... 10 HH80 - 120, VH80 - 100 .............................................................................................................................................. 10 SECTION 5. OVERHEAD VALVE ENGINE CARBURETORS .......................................................................................... 13 SECTION 6. GOVERNORS ............................................................................................................................................... 16 SECTION 7. IMPULSE FUEL PUMP ................................................................................................................................. 19 CHAPTER 3. REWIND STARTERS, ELECTRIC STARTERS, TROUBLESHOOTING AND GENERATORS ......................... 20 SECTION 1. REWIND STARTERS .................................................................................................................................... 20 SECTION 2. ELECTRIC STARTERS ................................................................................................................................ 22 SECTION 3. 12 VOLT STARTER TROUBLE SHOOTING CHART ................................................................................... 25 CHAPTER 4. GENERAL VALVE INFORMATION, CYLINDER HEAD AND BREATHER ASSEMBLY ................................... 27 SECTION 1. GENERAL VALVE INFORMATION ............................................................................................................... 27 SECTION 2. CYLINDER HEAD ......................................................................................................................................... 31 SECTION 3. BREATHER ASSEMBLIES ........................................................................................................................... 32 CHAPTER 5. PISTON AND RINGS, CONNECTING RODS AND CRANKSHAFTS ................................................................ 33 SECTION 1. PISTON AND RINGS .................................................................................................................................... 33 SECTION 2. CONNECTING RODS ................................................................................................................................... 35 SECTION 3. CRANKSHAFTS ........................................................................................................................................... 36 CHAPTER 6. CAMSHAFT, BEARINGS AND SEALS ............................................................................................................... 37 SECTION 1. CAMSHAFT .................................................................................................................................................. 37 SECTION 2. BEARINGS .................................................................................................................................................... 38 SECTION 3. SEALS ........................................................................................................................................................... 42 CHAPTER 7. DYNA-STATIC® BALANCING SYSTEM ............................................................................................................. 43 CHAPTER 8. IGNITION SYSTEMS, CHARGING SYSTEMS BATTERY SERVICE and ELECTRICAL CONTROL PANELS .......................................................................................................................................... 45 SECTION 1. IGNITION SYSTEMS .................................................................................................................................... 45 SECTION 2. CHARGING SYSTEMS ................................................................................................................................. 48 SECTION 3. BATTERY SERVICE ..................................................................................................................................... 53 SECTION 4. ELECTRICAL CONTROL PANELS .............................................................................................................. 56 CHAPTER 9. TROUBLESHOOTING ........................................................................................................................................ 61 CHAPTER 10. 8 H.P. & LARGER ENGINE SPECIFICATIONS AND TORQUES .................................................................... 66 SECTION 1. CROSS REFERENCE LIST FOR TABLE OF SPECIFICATIONS ................................................................ 66 SECTION 2. TORQUE SPECIFICATIONS ........................................................................................................................ 70 8 H.P. & LARGER ENGINES (EXCEPT VALVE-IN-HEAD) ......................................................................................... 70 SECTION 3. VALVE-IN-HEAD ENGINE SPECIFICATIONS ............................................................................................. 71 SECTION 4. TORQUE SPECIFICATIONS ........................................................................................................................ 73 VALVE-IN-HEAD .......................................................................................................................................................... 73 CHAPTER 11. EDUCATIONAL MATERIALS AND TOOLS ...................................................................................................... 74

C Tecumseh Products Company 1998

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CHAPTER 1. GENERAL INFORMATION SECTION 1. ENGINE IDENTIFICATION Tecumseh engine model numbers are stamped into the blower housing, or are located on a nameplate or tag on the engine in locations as illustrated.

OH160-170033 SER 8044C

SHORT BLOCKS. New short blocks are identified by a tag marked SBH (Short Block Horizontal) or SBV (Short Block Vertical). Original model tags of engines should always be transferred to a short block for correct parts identification.

INTERPRETATION OF MODEL NUMBER. The first letter designations in a model number indicate the basic type of engine. HH - Horizontal-Heavy Duty (Cast Iron) VH - Vertical-Heavy Duty (Cast Iron) OH - Overhead Valve-Heavy Duty (Cast Iron) The number designations following the letter indicates the horsepower of the engine. The number following the model number is the specification number. The last three numbers of the specification number indicate a variation to the basic engine specification. The serial number indicates the production data. Using model number OH160-170033, Serial 8044C as an example, interpretation is as follows: OH160-170033 - is the model and specification number. OH - Overhead Valve-Heavy Duty (Cast Iron) 160 - Indicates 16 horsepower. 170033 - is the specification number used for properly identifying the parts of the engine. 8044C - is the serial number. 8 - first digit is the year of manufacture (1998) 044 - indicates calendar day of that year (044 day or February 13, 1998). C - represents the line, shift or plant in which the engine was built at the factory.

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SECTION 2. ENGINE CARE FUELS. Use clean, fresh unleaded automotive gasoline in all Tecumseh four-cycle engines. (Leaded “regular” gasoline is an acceptable substitute.) NOTE: Do Not use gasoline containing methanol (wood alcohol). Gasoline containing a maximum of 10 ethanol or grain alcohol (sometimes called “gasohol”) may be used but requires special care when engine is unused for extended periods. See “STORAGE” instructions. ENGINE OIL, ALL FOUR CYCLE ENGINES: USE A CLEAN, HIGH QUALITY, DETERGENT OIL. Be sure original container is marked with engine service classification “SF - SJ.”

CAUTION: Remove spark plug wire before doing any service work on engine. 1. Service or replace air cleaner as necessary. 2. Inspect level and condition of oil; drain oil. 3. Remove blower housing, clean all dirt, grass or debris from intake screen, head and cylinder cooling fins and carburetor governor levers and linkage. 4. Remove cylinder head, remove carbon, inspect valves and cylinder bore. Replace head using a new head gasket. Torque to specifications.

FOR SUMMER (ABOVE 32°F, 0°C) USE SAE 30 OIL (SAE10W30 is an acceptable substitute.)

5. Remove carburetor, clean and install carburetor kit, make adjustment pre-sets where needed. Make sure fuel tank, fuel filters and fuel lines are clean. Reinstall carburetor, replacing any worn or damaged governor springs or linkage. Make proper governor adjustment.

FOR WINTER (BELOW 32°F, 0°C) USE SAE 5W20 OR 5W30 OIL. (SAE10W is an acceptable substitute.)

6. Remove flywheel, check for leaks in oil seals, check flywheel key and reinstall flywheel. Replace spark plug and check for spark.

(BELOW 0°F, -18°C ONLY) Use 0W30 oil or SAE10W oil diluted with 10% kerosene is acceptable.

7. Make sure all remote linkage is properly adjusted for proper operation.

NOTE: For severe, prolonged, winter operation of HH120 model, SAE10W oil is recommended.

8. Replace fuel and oil.

DO NOT USE SAE10W40 OIL.

OIL CHANGE INTERVALS. Change oil after first two (2) hours of operation and every 25 hours thereafter, or more often if operated under dusty or dirty conditions. OIL CHECK. Check oil every 5 hours or each time the equipment is used. Position equipment so the engine is level when checking the oil. BREAK-IN PROCEDURE. Proper break-in procedure is important for proper seating of rings, on a new engine or newly overhauled engine. Do normal work with the unit, running the engine under load. Vary the load on the engine frequently to aid in seating of the rings. The engine should not be allowed to idle or run at part throttle for extended periods during break-in. Work the engine but do not abuse it. TUNE-UP PROCEDURE. The following is a minor tune-up procedure. When this procedure is completed, the engine will operate properly or you may discover that further repairs may have to be performed. NOTE: It is recommended to use only factory parts in a Tecumseh engine. This is especially important with an air filter, since the use of any other than the specified part number may result in serious damage to the engine.

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9. Run engine and adjust carburetor and set R.P.M. to specifications found on Microfiche or computer parts lookup.

STORAGE: (IF THE ENGINE IS TO BE UNUSED FOR 30 DAYS OR MORE) CAUTION: NEVER STORE THE ENGINE WITH FUEL IN THE TANK INDOORS , IN ENCLOSED POORLY VENTILATED AREAS WHERE FUEL FUMES MAY REACH AN OPEN FLAME, SPARK OR PILOT LIGHT AS ON A FURNACE, WATER HEATER, CLOTHES DRYER OR OTHER GAS APPLIANCE. Gasoline can become unstable in less than 30 days and form deposits that can impede proper fuel flow and engine operation. To prevent deposits from forming, all gasoline must be removed from the fuel tank and the carburetor. An acceptable alternative to removing all gasoline is adding a fuel stabilizer to the gasoline. Fuel stabilizer (such as Tecumseh’s Part No. 730245) is added to the fuel tank or storage container. Always follow the mix ratio found on the stabilizer container. Run the engine at least 10 minutes after adding the stabilizer to allow it to reach the carburetor.

DRAINING THE FUEL SYSTEM: CAUTION: DRAIN THE FUEL INTO AN APPROVED CONTAINER OUTDOORS, AND AWAY FROM ANY OPEN FLAME OR COMBUSTION SOURCE. BE SURE THE ENGINE IS COOL. 1. Remove all gasoline from the fuel tank by running the engine until the engine stops, or by draining the fuel tank by removing the fuel line at the carburetor or fuel tank. Be careful not to damage the fuel line, fittings, or fuel tank. 2. Drain the carburetor by pressing upward on the bowl drain (if equipped) which is located on the bottom of the carburetor bowl. On carburetors without a bowl drain, the carburetor may be drained by loosening the bowl nut on the bottom carburetor one full turn. Allow to completely drain and retighten the bowl nut being careful not to damage the bowl gasket when tightening. 3. If "Gasohol" has been used, complete the above procedure and then put one half pint of unleaded gasoline into the fuel tank and repeat the above procedure. If Gasohol is allowed to remain in the fuel system during storage, the alcohol content will cause rubber gaskets and seals to deteriorate.

Change Oil: If the oil has not been changed recently, this is a good time to do it. Oil Cylinder Bore: 1. Disconnect the spark plug wire and ground the wire to the engine. Remove the spark plug and put 1/2 ounce (14 ml) of clean engine oil into the spark plug hole. 2. Cover the spark plug hole with a shop towel. 3. Crank the engine over slowly several times. CAUTION: AVOID SPRAY FROM SPARK PLUG HOLE WHEN SLOWLY CRANKING ENGINE OVER. 4. Install the spark plug and connect the spark plug wire.

Clean Engine: Remove the blower housing and clean all dirt, grass or debris from the intake screen, cylinder head, cylinder cooling fins, carburetor, governor levers and linkage.

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CHAPTER 2. AIR CLEANERS, CARBURETORS, GOVERNORS AND LINKAGE SECTION 1. AIR CLEANERS PAPER-TYPE AIR CLEANER SERVICE. Dry type paper air cleaners are utilized on all Tecumseh Large Frame engines. These air cleaners have treated paper elements with rubberlike sealing edges. These edges must seal properly to prevent dirt leakage. COVER

ELEMENT

POLYURETHANE-TYPE AIR CLEANER. Some Tecumseh Large Frame engines may use a polyurethane air filter in conjunction with a paper filter. GASKET

BASE SPACER

BOLT

BRACKET BOLT PAPER ELEMENT

SEALING EDGES

PAPER-TYPE AIR CLEANER SERVICE. Replace air filter once a year or more often in extremely dusty or dirty conditions. DO NOT ATTEMPT TO CLEAN OR OIL FILTER. Be sure to clean base and cover thoroughly before installing new paper filter. NEVER RUN THE ENGINE WITHOUT THE COMPLETE AIR CLEANER INSTALLED ON THE ENGINE. NOTE: Serious damage to the engine may result in using other than the specified part number filter. Use factory recommended parts only.

BACK COVER

POLY OUTER ELEMENT FRONT COVER

POLY-TYPE AIR CLEANER SERVICE. Clean and re-oil every 3 months or every 25 operating hours, whichever comes first. Clean daily if used in extremely dusty or dirty conditions. Proceed as follows: Remove wing nut and cover. Slide foam filter off paper filter. Wash foam filter in water and detergent solution and squeeze, Don’t twist until all dirt is removed. Rinse thoroughly in clear water. Wrap in a clean cloth and squeeze, Don’t twist until completely dry. Saturate foam filter with engine oil and squeeze, Don’t twist to distribute oil and remove excess oil. Clean top side of base and inside of cover thoroughly. Replace foam filter, cover and wing nut. Tighten wing nut securely. NEVER RUN ENGINE WITHOUT COMPLETE AIR CLEANER INSTALLED ON ENGINE.

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SECTION 2. GENERAL CARBURETOR INFORMATION CARBURETOR IDENTIFICATION. Tecumseh carburetors are identified by a model number and code date stamping on the carburetor as illustrated. ALTERNATE LOCATION FOR MODEL NUMBER

89 3 F

89 3 F 5

This carburetor is used on the Overhead Valve engine 12, 14, 16 & 18 horsepower.

CARBURETOR CODE DATE

CARBURETOR MODEL NUMBER

When servicing carburetors, use the engine model number or the model number on the carburetor and proper section in the Master Parts Manual or Microfiche Catalog for proper service information. CARBURETOR MODEL NUMBER

FLOAT-FEED CARBURETORS. Float-feed carburetors use a hollow metal float to maintain the operating level of fuel in the carburetor. As the fuel is used, the fuel level in the carburetor bowl drops and the float moves downward. This actuates the inlet needle valve, to allow fuel to flow by gravity into the fuel bowl. As the fuel level in the bowl again rises, it raises the float. This float motion adjusts the fuel flow at the proper rate and keeps the fuel at the proper mixture level.

These carburetors are used on some HH80-100120 and VH80-100 engines.

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SECTION 3. TECUMSEH CARBURETORS Following are initial carburetor adjustments to be used to start the engine. After the engine has reached operating temperature make final adjustments. Main Adjustment Screw

HH80-100-120 VH100, 1-3/4 turns.

Idle Adjustment Screw

HH80-100-120 VH100, 1-1/4 turns

The Master Parts Manual or Microfiche has a direct engine-to carburetor reference list. Further identification of the carburetor is stamped on the carburetor body as shown. Refer to the standard service part number and the identification number on the carburetor body, in any correspondence.

THROTTLE SHUTTER

NOTE: IDENTIFYING MARK WILL BE FOUND IN THE 3 O’CLOCK POSITION

CHOKE. Examine the choke lever, shaft and shutter prior to disassembly. Replace any worn parts. 1. Remove the screw in the center of the choke shutter and pull out the choke shaft lever assembly.

CHOKE LEVER THROTTLE LEVER

2. When reassembling, replace the choke shutter with identifying marks as positioned prior to disassembly. Hold the choke shaft securely into the bearing bore when replacing the choke shutter. CHOKE SHUTTER CUT OUT CLEARANCE FOR INTERNAL VENT TUBE

WELCH PLUG

CARBURETOR MODEL NUMBER

CARBURETOR DISASSEMBLY, INSPECTION AND ASSEMBLY. Carefully disassemble carburetor, removing all non-metallic parts, i.e., gaskets, viton seats and needles, “O” rings, fuel pump valve, etc. THROTTLE. Examine the throttle lever shaft and shutter prior to disassembly. Replace any worn parts.

IDLE ADJUSTMENT SCREW. Remove the idle screw from the carburetor body and examine the point for damage to the seating surface of the taper. Replace any damaged parts.

1. Remove the screw in the center of the throttle shutter and pull out the throttle shaft lever assembly. BAD

2. When reassembling, replace the throttle shutter with identifying marks as positioned prior to disassembly. The throttle shaft must be held in tight to the bottom bearing to prevent the throttle shutter from riding on the throttle bore of the body, causing excessive throttle shutter wear and governor hunting.

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GOOD

HIGH SPEED ADJUSTMENT SCREW. For service, examine the taper of the high speed adjustment screw. If the taper is damaged at the area where it seats, replace the screw and fuel bowl retainer nut as an assembly.

INLET NEEDLE. The inlet needle is anchored to the float tab by a clip, to assure proper movement of the inlet needle off of the seat when the float drops. The inlet needle clip must be positioned as shown during reassembly.

FUEL BOWL RETAINING NUT. Remove the fuel bowl retaining nut including fiber washer. Examine the small fuel passage in the annular groove in the retaining nut. This passage must be clean for the proper transfer of fuel into the idle metering system. Replace any worn parts. When replacing, torque the fuel bowl nut to 50-60 inch pounds.

CLIP OPEN END OF CLIP

LONG END OF CLIP

THROTTLE END

FUEL BOWL FLAT OF FUEL BOWL TOWARD FUEL INLET FITTING

FIBER WASHER TORQUE TO 50 - 60 INCH POUNDS

FUEL BOWL RETAINING NUT “O” RING BRASS WASHER HIGH SPEED ADJUSTMENT SPRING AND SCREW

FUEL BOWL. Check the bowl for corrosion or dirt. Replace if necessary. The fuel bowl must be free of dirt and corrosion. When tearing down carburetor for repair, replace fuel bowl “O” ring. Before installation lubricate the “O” ring with a small amount of oil for easier installation. The fuel bowl flat surface must be positioned on the same side of the carburetor as the fuel inlet fitting or same side as the float hinge pin to assure full travel of the float.

CHOKE END

Examine the inlet needle. If any wear is evident, or any of the corners show signs of rounding, the needle should be replaced. The inlet needle hooks onto the float tab by means of a spring clip. To prevent binding, the long, straight end of the clip should face the choke end of the carburetor as shown. SERVICING THE VITON SEAT. a. REMOVAL. If the seat is to be replaced use the bent end of a paper clip or wire with a 3/32'’ (.24 mm) hook. Push the hook through the Viton seat hole. Then with the hook, pull the Viton seat out. Replace with a new seat. NOTE: A #4 crochet hook can also be used for removal. b. INSTALLATION. NOTE: After thoroughly cleaning the cavity, moisten the viton seat with oil. Insert the seat with the grooved side into the cup. Press the viton seat squarely into the base with a punch.

“O” RING CHECK FOR CORROSION AND DIRT

3/32” (.24 mm) HOOK END

FUEL BOWL

FLOAT. Remove the float. Examine the float for crushing or holes. Examine the float hinge bearing surfaces through which the float hinge pin passes and replace if worn. INSTALLATION OF VITON SEAT INLET NEEDLE INSERT THIS SEATS AT THIS FACE FIRST POINT REMOVAL OF VITON SEAT

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HIGH SPEED NOZZLE. The carburetor body contains a main nozzle emulsion tube pressed into the carburetor body to a predetermined depth and positioned within the venturi of the carburetor. Do not attempt to remove this main nozzle. Repositioning of this nozzle will seriously affect the metering characteristics of the carburetor and will require replacement of the entire carburetor.

CARBURETOR BODY. When removing the choke and throttle shafts, check shafts and bearings in carburetor body for wear. Any looseness in these areas can cause dirt to enter the engine and cause premature wear. If dust seals are present, these should be positioned next to the carburetor body. To do a proper cleaning job, welch plugs should be removed to expose drilled passages. To remove the welch plug, sharpen a small chisel to a sharp wedge point. Drive the chisel into the welch plug, push down on chisel and pry plug out of position. PIERCE PLUG WITH TIP

SMALL CHISEL

WELCH PLUG TO BE REMOVED PRY OUT PLUG

MAIN NOZZLE EMULSION TUBE DO NOT REMOVE

DO NOT ALLOW CHISEL POINT TO STRIKE CARBURETOR BODY

ABOUT 1/8” (3.2 MM) WIDE

WELCH PLUG

FUEL INLET FITTING. If necessary, this fitting can be removed by pulling and twisting. Be sure to install the fitting in the same position as the original. When installing the fitting, insert tip into the carburetor body, then coat the exposed portion of the shank with Loctite grade A; then press it in until the shoulder contacts the carburetor body. PRESS IN PARTIALLY THEN APPLY LOCTITE GRADE A SOME INLET FITTINGS UTILIZED A STRAINER

SMALL CHISEL

When all accessories and shafts have been removed, soak the carburetor in carburetor cleaner for a maximum of 30 minutes. Blow out all passages with compressed air in the opposite direction of normal fuel flow or use a soft tag wire. Clean all metallic parts with solvent. To install a new welch plug after cleaning, place the welch plug into receptacle with raised portion up. With a punch equal, or greater than the size of the plug, merely flatten the plug. Do not dent or drive the center of the plug below the top surface of the carburetor.

FLAT-END PUNCH

NEW WELCH PLUG

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SAME OR LARGER DIAMETER OF PLUG

FLOAT ADJUSTING PROCEDURE All Tecumseh carburetors with an adjustable float require the correct float height to achieve the proper operation and easy engine starts. To check the float setting, hold the carburetor in an upside down position. Remove the bowl nut, float bowl, and "O" ring. Place an 11/64" (4.369 mm) drill bit across the top of the carburetor casting on the opposite side and parallel to the float hinge pin. The float must just touch the drill bit when the bit is flush with the edge of the float. If the float is too high or too low, adjust the height by bending the tab accordingly. If the required adjustment is minor, the tab adjustment may be made without removing the float and carefully inserting a small bladed screwdriver to bend the tab.

FLOAT

FLOAT HINGE AND PIN

FLOAT SETTING

11/64” (4.369 mm)

ADJUSTING TAB

INLET NEEDLE AND SEAT

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SECTION 4. WALBRO CARBURETORS HH80 - 120, VH80 - 100 WALBRO CARBURETORS. Following are initial carburetor adjustments to be used to start the engine. After the engine has reached operating temperature, make final adjustments. Main Adjustment Screw

HH80, 100, 120 VH80, 100, 1-1/2 turns off seat

Idle Adjustment Screw

HH80, 100 120 VH80 100 1-1/4 turns off seat

For proper carburetion the atmospheric vent MUST be open. Examine and clean if necessary. A sluggish engine speed control may at times be caused by dirt or paint on the throttle return spring. Clean if required.

Install the throttle plate with the numbers (if present) facing out when closed. Move the throttle shaft to the closed position, place the throttle plate on the shaft and secure with the retaining screws. The throttle should move freely. If binding is present, correct by loosening screws and repositioning throttle plate. THROTTLE LEVER THROTTLE SHUTTER THROTTLE STOP SCREW MOUNTING FLANGE

INSTALL WITH NUMBERS OUT

62 29

Examine the inlet needle. “A” is a needle that is serviceable, if the tip appears damaged as “B”, replace needle and seat assembly. Tighten the inlet seat to 40 to 50 inch pounds (4.5 - 5.7 Nm). Always use a new gasket. Clean all dirt from the inlet seat cavity.

Choke lever positioning is maintained by the stop spring, replace if damaged. The fuel inlet fitting should be checked if leakage is detected in the carburetor area. Do not screw in too tight, this may crack the carburetor body. The fuel bowl drain should also be examined in event fuel leakage is detected. It may be necessary at times to replace the internal rubber seat. Examine the throttle return spring if slow engine response is noted during operation. Correct by cleaning the throttle return or realigning the throttle plate.

Normally the main nozzle should not be removed. It is possible to clean the carburetor with solvent and compressed air. Remove and replace the main nozzle only if the high speed needle seat is damaged or because of excessive dirt.

MAIN NOZZLE EMULSION TUBE

“B” DAMAGED - Replace

INLET NEEDLE “A”

CHOKE STOP SPRING THROTTLE LEVER

CHOKE LEVER

THROTTLE RETURN SPRING

INLET SEAT

SECONDARY IDLE DISCHARGE

FUEL INLET

PRIMARY IDLE DISCHARGE THROTTLE SHUTTER FUEL BOWL NUT

FUEL BOWL

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HIGH SPEED ADJUSTMENT SCREW

INLET SEAT GASKET

INLET SEAT CAVITY

Do not remove the main nozzle. If it is necessary to remove the main nozzle to aid in cleaning, discard the main nozzle and use a service replacement nozzle with an under cut in the thread area. If the nozzle removed is under cut it can be reused. This procedure must be followed to assure delivery of fuel to the idle system. UNDERCUT ANNULAR GROOVE

EARLY SERVICE MAIN NOZZLE (REUSABLE)

ORIGINAL MAIN NOZZLE DO NOT REUSE IF REMOVED

Float settings are measured opposite the float hinge. Remove float by pulling out float axle. Bend adjusting tab to correct setting. Always remove the float to make adjustments. Examine the float hinge and axle for wear. If evident replace the parts. FLOAT

FLOAT HINGE AND AXLE

NEW

This shows early and new needle valve, seat, gasket, and spring assembly for large horsepower engine carburetors. Early carburetors have a metal-to-metal needle and seat contact. The float setting for this model will be .110'’ - .130'’ (2.794 - 3.362 mm). New carburetors contain a viton seal in the seat and a spring on the needle. For engines with the new carburetor and having a fuel pump, the float setting is .140 (3.556 mm). For engines with the new carburetor, without a fuel pump, the float setting is .075 (1.905 mm).

FLOAT SETTING

Ô Ô

The float setting on carburetors used on vertical 8 and 10 H.P. engines is .070'’ to .110'’ (1.778 - 2.794 mm). No variance for carburetor having a fuel pump. The gasket must fit over the float spring as shown to avoid cutting by the spring when assembled. ADJUSTING TAB

INLET NEEDLE AND SEAT

GASKET GOES OVER SPRING (IF EQUIPPED)

CHOKE END OF CARBURETOR

ENDS OF SPRING POINT TOWARD CHOKE END OF CARBURETOR

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When assembling the float to the carburetor body, position the needle spring on the adjusting tag so that it hangs down. Hold the float spring under tension until the carburetor body will support the slight spring tension.

Prior to removing the fuel bowl nut, remove the high speed adjustment needle. Use a 7/16'’ box end wrench or socket to remove the fuel bowl nut. When replacing the fuel bowl nut be sure to position the fiber gasket under the nut and tighten securely.

NOTE: THE SPRING ENDS MUST POINT TOWARD THE CARBURETOR CHOKE END.

Examine the tip of the high speed needle, if it appears as illustrated, replace. If the tip of the high speed adjustment needle is damaged, the seat is probably damaged. The seat is part of the main nozzle. When replacing the high speed needle the main nozzle should also be replaced. HIGH SPEED ADJUSTMENT NEEDLE

TENSION SPRING FUEL BOWL “A” FUEL BOWL DRAIN

“O” RING HOLD SLIGHT SPRING TENSION WITH THUMB

Ô

Position the choke shaft and shutter in the closed position prior to tightening the screws. Hard starting may be due to insufficient choking action because of a misaligned choke plate. Correct by readjusting choke plate to close completely. A typical choke shutter found on horizontal engines is shown in the figure below. The full choke position of choke lever is counterclockwise when viewed from top of the carburetor. Note cut-out position of choke shutter. INSTALL WITH NUMBERS OUT

CCW

CHOKE SHUTTER 62 29

“B” DAMAGED (Replace)

FUEL BOWL NUT

OUTSIDE GASKET

Use new gaskets when rebuilding the carburetor. If the fuel bowl to carburetor body gasket does not seat, enlarge by stretching with 4 or 5 quick short strokes. Fiber gasket must be used between center of fuel bowl and carburetor body. The fuel pick up passage must be clean to assure adequate fuel flow from the fuel bowl to the metering systems. INSIDE FIBER GASKET

FUEL BOWL GASKET AND SEAT

AIR CLEANER MOUNTING

Figure below shows a typical choke shutter found on vertical engines. The full choke position of the choke lever is clockwise when viewing from the top of the carburetor. Note cut-out position of choke shutter. CHOKE SHUTTER

CW

AIR CLEANER MOUNTING NUMBERS OPPOSITE SIDE

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MAIN NOZZLE

FUEL PICK-UP PASSAGE

FLOAT

SECTION 5. OVERHEAD VALVE ENGINE CARBURETORS Overhead valve engines utilize Walbro carburetors. THROTTLE PLATE

CHOKE LEVER

THROTTLE RETURN SPRING IDLE SPEED ADJUSTMENT SCREW

CHOKE SHUTTER

IDLE SPEED ADJUSTMENT SCREW

RETAINING SCREWS

ATMOSPHERIC VENT OPENING

FUEL BOWL

FUEL BOWL RETAINING NUT

HIGH SPEED ADJUSTMENT SCREW

CARBURETOR ADJUSTMENT. Carburetor factory adjustment should not be changed. However, if required, perform the following: with engine running (Allow engine to warm up for 5 minutes). Open throttle (speed control at “RUN” or “FAST” position). Adjust high speed adjustment screw per chart, clockwise or counterclockwise until engine runs smoothly. With control in idle or slow position, adjust idle speed adjustment screw to obtain correct idle speed. If necessary, readjust idle adjustment screw clockwise or counterclockwise until engine idles smoothly.

OH120 THRU OH180

THROTTLE PLATE

INSTALL WITH NUMBERS OUT

IDLE ADJUSTMENT SCREW

CARB.

CARBURETOR SERVICING Throttle Shutter Install the throttle shutter with the numbers facing out when closed. Move the throttle shaft to the closed position, place the throttle shutter on the shaft and secure with new retaining screws. The throttle should move freely. If binding is present, correct by loosening screws and repositioning throttle shutter.

HIGH SPEED ADJ. SCREW*

IDLE ADJ. SCREW*

1 TURN*

1 TURN*

MOUNTING FLANGE

THROTTLE SHUTTER

CHOKE SHUTTER. Position the choke shaft and shutter in the closed position to tighten the screws. Hard starting may be due to misaligned choke plate. Correct by readjusting the plate to close completely. INSTALL WITH NUMBERS OUT

CHOKE SHAFT

CHOKE SHUTTER

*All Adjustments Off of Seat

IDLE ADJUSTMENT SCREW. Close idle adjustment screw by turning clockwise. Close finger tight only. Forcing will damage screw. OPEN IDLE ADJUSTMENT SCREW: 1 turn counterclockwise. Start engine and with the throttle open (then return to idle position), adjust idle adjust screw one-eighth (1/8) turn at a time clockwise or counterclockwise until engine runs smoothly.

ATMOSPHERIC VENT

AIR CLEANING MOUNTING

HIGH SPEED ADJUSTING SCREW. Prior to removing the fuel bowl nut, remove the high speed adjusting needle. When replacing the fuel bowl nut be sure to position a fiber gasket on each side of the fuel bowl.

With control at “idle” or “slow” position, adjust idle speed adjustment screw to obtain correct idle speed. If necessary, readjust idle adjustment screw until engine idles smoothly.

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Examine the tip of the high speed adjustment screw. If the tip of the screw is damaged, the seat, which is part of the main nozzle, is probably damaged. When replacing the screw, the nozzle should also be replaced with a service replacement nozzle only.

INLET NEEDLE & SEAT. The inlet needle and seat are replaceable as an assembly. If the tip appears damaged, replace the needle and seat assembly. MAIN NOZZLE

HIGH SPEED ADJUSTMENT SCREW FUEL BOWL TENSION SPRING “A”

“O” RING

“B” DAMAGED Replace

RE-USE CHAMFERED INSERT EDGE FACE FIRST

“B” DAMAGED Replace INLET SEAT CAVITY FLOAT MOUNTING

INLET NEEDLE TIP SEATS AT THIS POINT OUTSIDE FIBER GASKET

MAIN NOZZLE. Normally the main nozzle should not be removed, if it is, clean the carburetor with solvent and compressed air. Remove and replace the main nozzle only if the seat is damaged or is excessively dirty.

Replace the float and axle if wear is evident. The float must measure .275” / .315'’ (6.985 / 8.001 mm) from top of boss to surface of float (closest to center). MEASURE AT EDGE CLOSEST TO CENTER

FLOAT HINGE AND AXLE

Ô

If it is necessary to remove the main nozzle, discard it and use a service replacement nozzle with an undercut in the thread area. If the nozzle removed is already under cut, it can be reused. This replacement assures delivery of fuel to the idle system.

FLOAT SETTING. Float Settings are measured opposite the float hinge. Remove float by pulling out float axle. Bend adjusting tab to correct setting. Always remove the float to make adjustments.

Ô

FUEL BOWL NUT

.275 (6.985 mm) .315 (8.001 mm) FLOAT

UNDERCUT ANNULAR GROOVE

INLET NEEDLE AND SEAT

ADJUSTING TAB

Position carburetor in an upright position.

SERVICE MAIN NOZZLE - REUSABLE

ORIGINAL MAIN NOZZLE (DO NOT REUSE IF REMOVED)

If float is lower than dimensions shown in figure, bend outside tab GENTLY so float does not drop plus or minus .060'’ (1.524 mm) from base of boss.

FLOAT

OUTSIDE TAB BOSS

14

.060 (1.524 mm)

ASSEMBLING SEAT, SPRING & FLOAT. Shown below is the float, hinge pin, seat and the float spring. DAMPER SPRING

FIXED HIGH SPEED CARBURETOR. On carburetors of a later design the high speed screw has been replaced by a fixed speed nut. Adjustment is made only on the idle adjustment screw since the high speed setting is fixed.

PIN

FLOAT

When assembling the float to the carburetor body, position the needle spring on the adjusting tang so that it hangs down. Hold the float damper spring under tension until the carburetor body will support the slight spring tension. The spring ends must point toward the carburetor choke end. HOLD SLIGHT SPRING TENSION WITH THUMB

IDLE ADJUSTMENT SCREW FIXED SPEED NUT

WALBRO WHG. The early production OH engine was equipped with a LMH carburetor. The newer engines since 1987 have been manufactured with a WHG carburetor. Service replacements are all WHG, which include an instruction sheet covering service.

The bowl gasket must be positioned over the float spring as shown. FUEL BOWL GASKET AND SEAT INSIDE FIBER GASKET

FUEL PICK-UP PASSAGE

WHG

LMH

WHG

LMH

NEW WHG

EARLY LMH

FLOAT

GASKET GOES OVER SPRING

15

SECTION 6. GOVERNORS This Governor Assembly is used on current production HH & OH Tecumseh Engines. SHAFT PRESSED TO GEAR GOVERNOR GEAR

There is an oil groove on the inside of the spool to prevent oil pressure from building up under the spool. Position the governor gear and flyweight assembly on the governor gear shaft. Secure with a retaining ring. Place the governor spool on the governor gear shaft. The spool is positioned on the governor gear shaft with the fingers of the flyweight under the rim of the spool. Some models have an oil hole in the closed end for lubrication. CAUTION: On reassembly make sure hole is open. Other models have a groove on the inside that serves the same purpose.

WASHERS

PRESS GOVERNOR “GEAR SHAFT’ INTO THIS DIMENSION*

To position the governor gear assembly, insert the shaft opposite the flyweights into the cylinder block. SPOOL

1” (25.4 mm)

RETAINING RING GROOVE GOVERNOR GEAR

OIL HOLE (ON SOME MODELS)

FLYWEIGHT ASSEMBLY

*1.031” (26.187 mm) ON MODELS WITH WASHER

WASHER ON SOME MODELS

GOVERNOR GEAR SHAFT

WASHER

Position the governor gear assembly (with washer under governor gear) to mesh with the camshaft gear. Place the governor spool (with washer under the spool) on the governor gear assembly, with the fingers of the flyweights under the rim of the spool. GOVERNOR GEAR AND FLYWEIGHT ASSEMBLY

GOVERNOR SPOOL GOVERNOR SHAFT

GROOVED SLOT (INTERNAL)

GOVERNOR GEAR

16

FLYWEIGHT

RETAINING RING

Remove the governor gear shaft by threading the shaft with 1/4-28 die. Place a number of washers on the shaft and turn on a nut. By tightening the nut against the washers the shaft will be pulled from the cylinder. For old style governor assembly, position the governor gear shaft over the opening in the cylinder block and tap lightly with a hammer to start. Use a press to position. Refer to top picture for proper pressed in depth. Measure from the top of the governor gear shaft to the machined surface on the cylinder block.

CYLINDER COVER

GOVERNOR ADJUSTMENT FOR HORIZONTAL ENGINES

GOVERNOR ROD PIVOT POINT

“C”

GOVERNOR SPRING MOVE TO ‘RUN’ POSITION

“A” RETAINING RING “B” GOVERNOR SPOOL CONTACTS LEVER TURN CCW

The governor rod is retained in the cylinder cover bushing with a retaining ring. The governor spool moves the governor rod by contacting the lever. Outward movement of the governor spool moves the governor levers and carburetor throttle to a closed position. The lever must contact the governor spool tightly for best governor control and for correct adjustment procedure. BEARING WITH SEAL TO OUTSIDE BEARINGS

BEARING END FLUSH WITH CASTING

GOVERNOR ADJUSTING SCREWS

1. SETTING VARIABLE SPEED ADJUSTING SCREW. Before attaching the bowden wire, set the engine for maximum R.P.M. (See Mfg. specifications) with engine running. Use a good tachometer. Move lever “A” clockwise until lower end strikes the adjusting screw at “1”. (See picture below) Loosen lock nut on adjusting screw and turn in to decrease R.P.M. Turn out to increase R.P.M. CAUTION: DO NOT EXCEED RECOMMENDED R.P.M.

RETAINING RING WASHER

The governor rod on some valve-in-head model engines utilize needle bearings. If bearing(s) are removed, always install new bearing(s). Remove with 3/8'’ (9.525 mm) diameter punch and mallet. To install, tap the first bearing in until the bearing end is flush with casting. Holding a finger over hole will indicate when bearing is driven into casting far enough. Drive the outside bearing in with edge flush with outside surface of casting and seal (in bearing) at outside end. GOVERNOR ADJUSTMENT FOR HORIZONTAL ENGINES (See Picture: Governor Adjustment for Horizontal Engines)

2. ADJUSTING FIXED SPEED. The fixed speed adjusting screw is the optional position “2”. Adjust it by starting the engine, then loosening the locknut. Turn screw in to increase R.P.M. and out to decrease R.P.M.

IDLE

HOLE “B” (CW) HOLE “C” ADJUSTING SCREW FIXED SPEED POSITION “2” OPTIONAL

Move remote controls to RUN position.

“A” LEVER PIVOT (CW)

Loosen Screw “A”. Pivot plate “B” counterclockwise (ccw) and hold.

BOWDEN WIRE CLAMP “B”

FAST

ADJUSTING SCREW VARIABLE SPEED POSITION “1” STANDARD

BOWDEN WIRE CLAMP “C”

Move lever “C” to left. Tighten screw “A” securely. When the governor is properly set, the carburetor throttle lever will be in a wide open position when the controls are set for starting. The governor spring is to be anchored in the bottom center hole (D) of plate “B”. Do not stretch or cut the governor spring. Above adjustments will correct any variations in governor control.

17

VERTICAL CRANKSHAFT GOVERNOR ADJUSTMENT. Move remote controls to RUN position. Loosen screw “A”. Turn plate “B” counterclockwise (ccw) and hold.

ADJUSTING FIXED SPEED. The fixed speed adjusting screw is the optional position “2”. Adjust it merely by starting the engine and after loosening the lock nut turn screw in (clockwise) to increase spring tension and hold engine at higher R.P.M. and out (counterclockwise) to decrease tension on spring and allow speed to be decreased more easily.

Move lever “C” to left.

“FIXED SPEED”

Tighten screw “A” securely. When the governor is set properly the carburetor throttle will be in wide open position.

BOWDEN WIRE CLAMP “B”

HOLE “C”

GOVERNOR ADJUSTMENT VERTICAL THROTTLE TOWARD FULL OPEN

THROTTLE TOWARD Ô FULL CLOSED

HOLE “B”

Ô

GOVERNOR SPRING

BOWDEN WIRE CLAMP “C”

“A” LEVER

LEVER “C”

SCREW “A” “D” PLATE “B”

GOVERNOR ADJUSTING SCREWS

TURN CCW

VARIABLE SPEED ADJUSTMENT. Before attaching the remote speed control (bowden wire) set the engine for maximum R.P.M. (See Mfg. specifications). Use a good tachometer. Move lever “A” clockwise until lower end strikes the adjusting screw “1”. Loosen lock nut on adjusting screw “1” and turn in (clockwise) to decrease R.P.M. and out counterclockwise to increase R.P.M. CAUTION: DO NOT EXCEED RECOMMENDED R.P.M.

18

ADJUSTING SCREW FIXED SPEED POSITION “2” (OPTIONAL)

ADJUSTING SCREW VARIABLE SPEED POSITION “1” (STANDARD)

SECTION 7. IMPULSE FUEL PUMP IMPULSE FUEL PUMP. This pump is mounted onto the carburetor inlet and has connections from the fuel supply and also a pulse line to the engine crankcase. CAUTION: IN ORDER FOR THE PUMP TO OPERATE SATISFACTORILY THE CORRECT OIL LEVEL IN THE CRANKCASE MUST BE MAINTAINED. TOO MUCH OIL WILL ADVERSELY EFFECT THE PUMPS OPERATION.

FOUR SCREWS INTO BACKSIDE OF PLATE

TO BACKSIDE OF PLATE WHEN ASSEMBLED THIS SIDE FACES INTO CONCAVE CAVITY OF ABOVE ASSEMBLY

It is operated by changing pressure created by the engine piston movement and transmitted to the pump through a pulse line. The increasing and decreasing pressures acting on the diaphragm and flap valves lift fuel from the fuel tank to the carburetor of the engine.

SPRING IN HOLE CAVITY

CARBURETOR FITTING

ATMOSPHERIC VENT

VALVE OPEN DIAPHRAGM

BUTTON WITH SPRING VALVE CLOSED

TYPE I

FILTER AIR BLEED VALVE CLOSED

FUEL SUPPLY

PULSE LINE TO CRANKCASE

±

±

CRANKCASE PRESSURE CRANKCASE SUCTION AND Ü FLOW DIRECTION Ô ATMOSPHERIC PRESSURE Ô ATMOSPHERIC PRESSURE Ô ACTING ON DAMPING ACTING ON DAMPING DIAPHRAGM DIAPHRAGM ÜFUEL FLOW

VALVE OPEN

SUCTION FUEL FLOW DIRECTION ATMOSPHERIC PRESSURE CAUSED FUEL FLOW

To service, separate the pump by removing the four (4) screws. Clean all new parts with a solvent and install a new kit which consists of coil springs, gaskets and diaphragms. The diaphragms must be installed against the center body with the gaskets against the outside covers. The parts are designed so they cannot be misassembled without damage. To test the unit, assemble the carburetor to the engine, leaving the pump off. Connect gravity fuel feed supply to the carburetor. With the pulse line connected to the pump and engine running, a definite flow should result.

PREVIOUS STYLE TYPE I

NEW STYLE TYPE II

The new style pump (TYPE II) will replace older (TYPE I) pumps. An assembly kit is available with instructions and all the parts needed to convert to the new style. If a complete replacement of an old style is not necessary, a repair kit is still available.

If the flow is erratic or intermittent, the pump needs repair or replacement.

19

CHAPTER 3. REWIND STARTERS, ELECTRIC STARTERS, TROUBLESHOOTING AND GENERATORS SECTION 1. REWIND STARTERS REWIND STARTER DISASSEMBLY PROCEDURE 1. Clamp starter in a vise and pull rope out, and clamp pulley. 2. Untie knot in rope and remove.

REASSEMBLY. Lubricate the recoil spring and center shaft with a small amount of light grease. Place the pulley over the center shaft and bottom. Insert a 1/8'’ (3.175 mm) punch or rod into the through hole in the pulley, and turn the pulley. This will aid in positioning and engaging the spring.

3. Slowly release spring tension. 4. Remove retainer screw, retainer cup; starter dog and spring, and brake spring. 5. Lift out pulley, turn spring and keeper assembly to remove from housing.

1/8” (3.175 mm) PUNCH

Replace all worn or damaged parts. BRAKE SPRING RETAINER

TURN PULLEY WASHER

RETAINER RETURN SPRING PULLEY

STARTER DOGS

SPRING REPLACEMENT. Disassemble the starter completely. New springs are enclosed in retainers. Be sure spring is positioned with wrapping in direction as illustrated. Position new spring and retainer over housing and press the spring out of the retainer into the starter housing. APPLY LIGHT LUBRICANT

20

REWIND SPRING

INSERT PUNCH INTO THROUGH HOLE AIDING SPRING ENGAGEMENT

REWINDING SPRING AND REASSEMBLY. Place the large washer, 1-3/8'’ (34.925 mm) over the center shaft. Insert the dogs, so that they will fold in close to the center. Press the brake spring on the retainer. The brake spring must be a tight fit on the retainer. Hold the retainer and brake spring assembly at an angle to engage the return spring to the dowel on the pulley. Secure with the center screw and washer and tighten securely. Failure of the starter to engage may be traced to either a loose center screw, or loose brake spring. Tighten the screw or replace the brake spring. Replace the rope as outlined.

VISE

ASSEMBLING STARTER TO ENGINE. It is important to center the starter hub containing the starter dogs in the center cup so there is equal contact on all the dogs into the teeth of the cup. Before securing the starter with the mounting screws, place the hub into the cup then pull the rope enough to cause the starter dogs to equally engage in the teeth. With the dogs securely in the cup, tighten the mounting screws to 40-60 inch pounds (4.5 - 6.8 Nm) torque. If mounting holes do not line up, blower housing is bent and must be replaced.

SCREW DRIVER

PREWIND 7 TURNS INSERT ROPE

TIGHTEN STARTER MOUNTING SCREWS AFTER HUB IS CENTERED IN CUP CLAMP WITH PLIERS TO RETAIN TENSION

ROPE REPLACEMENT. Prepare the rope, place a thin 3/4'’ (19.05 mm) diameter washer with a 1/4'’ (3.175 mm) hole on the rope and tie a knot. The other end of the rope should be thinned to a point for easier threading. Clamp the starter in a vise, upside down, by one leg opposite the rope outlet. Place a screw driver in the rope hole of the pulley and turn counterclockwise until tight, then allow to unwind until hole in pulley for rope lines up with hole in housing. Clamp the pulley in this position with lever action pliers. Clamp over starter housing and pulley, protect the painted surface. Insert the rope into the pulley hole and guide it with needle nose pliers through the rope outlet in the housing. Secure the handle with a double knot. Hold the rope taut, release the pliers and allow the rope to wind on the pulley.

STARTER CUP

STARTER HUB

STARTER

STARTER DOGS EQUALLY SECURE IN TEETH FOR CORRECT CENTERING OF STARTER HUB

ON SOME VALVE-IN-HEAD ENGINES: PULLEY (SHEAVE-TYPE) STARTER. Consists of a rope sheave-type. The engine comes equipped with starter rails and the blower housing is constructed with a removable plate for conversion to an electric start.

CENTER SCREW STARTER DOG

WASHER

21

SECTION 2. ELECTRIC STARTERS STARTER SERVICE, DISASSEMBLY AND INSPECTION. Part No. is found on identification tag. Used on large frame vertical and horizontal engines.

Test and trouble shooting procedures for 12 volt starters can be found in other Sections of this chapter. 2. Disassembly. a. Remove two (2) lock nuts from thru bolts on drive end of starter. b. Grasp drive end of starter and remove from housing as an assembly.

PART NO.

HOUSING

LOCK NUTS (2)

Repair of these starters consists of replacement of parts shown in the exploded view. 1. Testing Test 12 Volt starters under the following conditions: a. Conduct test with fully charged battery. b. Engine and oil temperature approximately 70° F (21°C). c. Engine contains recommended oil. d. Cranking test not to exceed 10 seconds. e. Parasitic loads removed from engine. MODEL

AMPERES

ENGINE RPM

33835

70 MAX.

600 MIN.

THRUST WASHER DRIVE END

c. Remove dust cover, retaining ring, spring retainer, anti-drift spring, gear and engaging nut. Remove drive end cap from armature. ARMATURE

ENGAGING NUT LOCK NUTS (2) SPRING

GEAR

THRUST WASHER

RETAINING RING

THRUST WASHER

HOUSING & ARMATURE NOT AVAILABLE ORDER COMPLETE SYSTEM

DRIVE END CAP SPRING RETAINER DUST COVER

d. To remove end cap assembly, loosen the nut on terminal post. Remove the lock nuts and thru bolts from starter housing. Remove brushes or brush card separately or as an assembly. NOTE: Care must be taken in removing and reinstalling brush springs to eliminate damage to spring and malfunction of brushes. 3. Inspection Inspect, clean and replace parts if necessary. Test motor parts for open and shorted circuits.

22

BRUSH CARD

NEW STARTER MOUNTING SCREWS AND WASHERS

BRUSH AND BRUSH SPRING (4)

LOCK NUT ADJUSTING BOLT

CYLINDER TERMINAL POST THRU BOLTS (2) COMMUTATOR END CAP

LOCK NUTS (2)

4. Assembly a. Install drive end cap, engaging nut and gear, anti-drift spring, spring retainer, retaining ring, and dust cover to armature. Install armature into housing. b. Install brush card assembly and two (2) thru bolts so stops on bolts will secure brush card. Secure lock nuts on drive end of starter. c. Install thrust washer on armature and install commutator end cap. Insure that the twopiece grommet is properly installed to prevent moisture from entering this area. d. Install end cap lock nuts. COMMUTATOR END CAP LOCK NUTS (2)

TWO PIECE GROMMET AND TERMINAL BOLT

When using starter motor, part no. 33835 to replace starter part no. 32817 on vertical crankshaft models, proceed as follows. 1. Remove the two (2) 5/16-18 x 7/8'’ (22.225 mm) screws that attached the original starter and discard. 2. Install the 5/16-18 x 1-3/8'’ (34.925 mm) adjusting bolt through the hole in the starter bracket with a lock nut on each side of the bracket. Position bolt so head will not touch cylinder when starter is installed. 3. Install motor with two (2) 5/16-18 x 5/8'’ (115.875 mm) screws and lockwashers. Torque screws to 140-170 inch lbs. (18.2 - 19.2 Nm).

STARTER MOTOR TESTS a. Preliminary Tests Before checking the starter motor perform the following preliminary checks: 1. Battery must be at least 3/4 full charge. 2. Determine parts such as switch, solenoid, between power source and starter motor are in good working order. 3. Terminals must be bright and clean for full conductance. 4. Check wires for breaks, insulation breakdown. 5. Proper size (gauge) wire between power source and starter motor. 6. If starter motor does engage the flywheel but fails to crank engine, check the engine for excessive friction caused by a seized rod or piston. 7. Check related parts such as clutches, pulleys, etc. for excessive friction. b. Visual Checks Make a visual check of the starter motor before checking electrically. Remove the starter motor and check for freedom of operation by turning the shaft. Look for: 1. Worn out brushes. 2. Weak brush springs. 3. Dirt on the commutator bars. 4. Armature binding, caused by dirt or bushings being gummed up through excessive lubrication. STARTER CHECKING AND SERVICE. Remove nuts at both ends of starter and take off rear end cap. CHECK FIELD. Using a continuity light or ohm meter, check field by attaching one lead to each field coil connection. Continuity should exist between these two points. Check continuity between each field coil connection and the starter housing. No continuity should exist.

4. Turn adjusting bolt so head of bolt securely bottoms on cylinder. Tighten nuts to hold bolt in position. 23

ARMATURE CHECK. If commutator bars are glazed or dirty they can be turned down in a lathe. While rotating, hold a strip of 00 sandpaper lightly on the commutator, moving it back and forth. (Do not use emery cloth). Recut grooves between commutator bars to a depth equal to the width of the insulators.

3. With a pliers or vise grip tool, grasp the throughbolts as close to the flanged end as possible (away from the threaded end), and remove the two nuts retaining the driving end cap of the starter. Remove the armature and driving cap assembly. Remove the two through-bolts, noting the position of the brush ground eyelet under the throughbolt flange. 4. Note the position and the connections of the brush wires. Clip the solid field wires as close to the connectors as possible. 5. Remove the brush card from the starter, noting the position of the clearance slot. Clean the starter and all parts of accumulated dust and dirt. Scrape the insulating varnish off of the solid field wires, back approximately 1/2” (12.7 mm) from ends.

Using a continuity tester to make certain no continuity exists between the commutator (copper) and the iron of the armature, rotate armature and check out all commutator bars. The armature can be thoroughly checked with a growler if available. CHECK BRUSHES. Before removing armature, check brushes for wear. Make sure brushes are not worn to the point where the brush wire bottoms out in the slot of the brush holder. Brush springs must have enough strength to keep tension on the brushes and hold them against the commutator. If brushes need replacement, remove by unhooking terminals or clipping connections and resoldering. If brush card is warped from overheating, replace the brush card assembly. BRUSH CARD

6. Insert the new brush card into position, guiding the solid field wires through the proper slots in the brush card. 7. Using the proper crimp connector, crimp and solder the remaining brush leads to the solid field wires. Use a pair of pinchers or needle-nose pliers to hold the woven brush lead adjacent to the connector while soldering (this provides a heat sink so that solder does not flow up the brush lead). Using electrical tape or shrink tubing, insulate the crimped connection nearest the starter terminal post. Position the wires to prevent shorts or grounding of the starter. 8. Spread the brushes to install the armature into the housing, and replace the starter throughbolts, being sure to install them through the ground brush eyelet terminals. Install and tighten the drive end through-bolt nuts. Tighten securely, but do not over tighten as this may warp the new brush card and impair brush movement. 9. Replace the thrust washer on the end of the armature and replace the starter end cap. Install the starter end cap locking nuts and tighten securely. Tighten the nut on the starter terminal post.

BRUSH AND BRUSH SPRING (4) TERMINAL POST

INSTRUCTIONS FOR REPLACING STARTER BRUSH CARD #33848 ON STARTER #33835 1. Loosen the two nuts on the starter terminal post, but do not remove. 2. Remove the nuts holding the starter and cap in place. Remove the starter end cap. Note the thrust washer on the end of the armature.

24

10. Test the starter for proper operation before reinstallation on the engine.

SECTION 3 12 VOLT STARTER TROUBLE SHOOTING CHART PROBLEM

PROBABLE CAUSE

FIX

Does not function

Weak or dead battery

Check charge and/or replace battery.

Corroded battery terminals and/or electrical connections

Clean terminals and/or connections.

Brushes sticking

Free brushes. Replace worn brushes and those that have come in contact with grease and oil.

Dirty or oily commutator

Clean and dress commutator.

Armature binding or bent

Free armature and adjust end play or replace starter.

Open or shorted armature

Replace starter.

Shorted, open or grounded field coil

Replace starter.

Loose or faulty electrical connections

Correct.

Load on engine

Disengage all drive apparatus and relieve all belt and chain tension.

Electric starter cranks but no spark at spark plug.

Disconnect ignition cutoff wire at the engine. Crank engine. If spark at spark plug ignition switch, interlock switch and safety switch is inoperative. If no spark, check magneto. Check wires for poor connection cuts or breaks.

Electric starter does not crank engine

Remove wire from starter. Use a jumper battery and cables and attach directly to starter. If starter cranks engine the starter is okay; check solenoid, starter switches, safety switches and interlock switches. Check wires for poor connections, cuts or breaks.

Unit controls engaged

Insure all unit controls are in neutral or disengaged.

Low RPM

Worn bearings in cap assemblies Clean bearings or replace cap assemblies. Bent armature

Replace starter.

Binding armature

Free up armature. Adjust armature end play.

Brushes not seated properly

Correct.

Weak or annealed brush springs

Replace springs.

Incorrect engine oil weight

Insure the correct weight of oil is being used.

Dirty armature commutator

Clean commutator.

Shorted or open armature

Replace starter.

Loose or faulty electrical connections in motor

Correct.

Motor stalls under load Shorted or open armature Shorted field coil

Replace starter. Replace starter. 25

12 VOLT STARTER TROUBLE SHOOTING CHART (Cont.) PROBLEM

PROBABLE CAUSE

Intermittent operation Brushes binding in holders

Free up brushes. Replace worn brushes and those that have come in contact with grease and oil.

Dirty or oily commutator

Clean and dress commutator. Replace any brush that has come in contact with grease or oil.

Loose or faulty electrical connections

Correct.

Open armature

Replace starter.

Break in electrical circuit

Disconnect ignition cutoff wire at the engine. Crank engine. If spark, check ignition switch, safety switch, and interlock switch. Check wires for poor connections, cuts or breaks.

Sluggish Dirt and oil on drive assembly disengagement of the and at armature shaft drive assembly pinion gear Bent armature

26

FIX

Clean drive assembly and armature shaft and lubricate shaft splines.

Replace starter.

CHAPTER 4. GENERAL VALVE INFORMATION, CYLINDER HEAD AND BREATHER ASSEMBLY SECTION 1. GENERAL VALVE INFORMATION Adjusting valves for 8 horsepower and larger engines (except valve-in-head engines) Intake valve gap .010, (.254 mm) exhaust valve gap .020, (.508 mm) set when engine is cold. Rotate the engine to Top Dead Center of the compression stroke, this will assure that the lifter is not raised by the compression relief pin. Valve stem ends must be ground flat when adjusting valve gap. An uneven or concave end can cause abnormal wear to the valve train. The outside of the valve stem guide also guides the valve spring. A valve spring cap is used only on the bottom of the spring. A pin through the valve stem retains the spring. Use a step type reamer to enlarge valve guides if worn. Oversize valves are 1/32'’ (.787 mm) larger in diameter than standard. (For oversize reamer, Consult Chapter 11). Do not enlarge the valve lifter guide, lifters with oversize stems are not available. VALVE GUIDE MAY BE OVERSIZED 1/32” (.787 mm)

TURN ADJUSTING SCREW: CLOCKWISE TO DECREASE LASH, COUNTERCLOCKWISE TO INCREASE LASH. ROCKER ARMS

LOCKNUTS

FEELER GAUGE VALVE STEM

ADJUSTING SCREW

INTAKE .005 (.127 mm) EXHAUST .010 (.254 mm)

VALVES. Valves must be in good condition, properly sealing and the proper gap must be maintained for full power, easy starting and efficient operation. VALVE REMOVAL On 8 H.P. and Larger (except valve overhead engines). To remove valves, raise the lower valve spring caps, while holding the valve head tightly against the seat, and remove pin.

VALVE STEM AND SPRING GUIDE

VALVE CAP

EXHAUST VALVE GAP .020 (.508 mm) COLD

INTAKE VALVE GAP .010 (.254 mm) COLD

VALVE LIFTER GUIDE DO NOT OVERSIZE OIL RETURN HOLE

ADJUSTING VALVES ON OVERHEAD VALVE ENGINES. Remove the breather and top half of the valve cover. Rotate the engine to Top Dead Center of the compression stroke. Adjust the exhaust valve to .010 (.254 mm) and .005 (.127 mm) for the intake valve. Assure that the locknut is loosened before attempting to turn adjusting screw. After the locknut is loosened, turn the adjusting screw with an open end wrench. Turn adjusting screw clockwise to decrease clearance and counterclockwise to increase clearance.

27

VALVE REMOVAL PROCEDURE FOR VALVE-INHEAD ENGINES. The following is necessary for cylinder head disassembly. REMOVAL OF ROCKER ARM HOUSING PARTS. Locate the piston at top dead center for easier access in servicing the valve train. After removing the rocker arms by removing the retaining rings, it may be necessary to loosen the locknut and back off the adjusting screw before pulling off the rocker arms. NOTE: Rocker arm shaft is not an inseparable unit from the rocker arm housing and should not be removed from the housing. LOWER VALVE SPRING CAP

UPPER VALVE SPRING CLIP

PUSH RODS

REMOVAL OF ROCKER ARM HOUSING. Remove rocker arm housing by removing the retaining cap screws. The valve spring retainer cupped side must be facing in the up position. A white Teflon “O” Ring is used under the valve spring retainer on the exhaust valve. The regular black rubber “O” Ring is used under the valve spring retainer on the intake valve. Be careful not to switch rings, or damage may result. Remove head to remove the valves - Reverse procedure for reassembly. VALVE SPRING RETAINER

CHAMFER

“O” RING

ROCKER ARM HOUSING RETAINING SCREWS, WASHERS AND SEALING “O” RINGS VALVE SPRING

ROCKER ARM SHAFT

REMOVAL OF VALVE SPRINGS. Use a valve spring compressor tool, part No. 670237A to compress the valve spring and remove the valve retainers. Be sure piston is at T.D.C. The valve cap is then taken off for removal of the spring. When reinstalling the valve cap and retainers after valve servicing, it may be necessary to hold both valves in their seats until the springs, cap, and retainer have been installed on the valve stems. Access can usually be gained through the exhaust and intake manifold in the head. RETAINERS HELD BY SPRING TENSION AGAINST THE CAP

ROCKER ARM SHAFT. The rocker arm shaft is not a replaceable part. The rocker arm housing, rocker arm shaft and screw are an inseparable assembly.

ROCKER ARM SHAFT RETAINING SCREW

RETAINER

VALVE SPRINGS FREE LENGTH FOR 8 HORSEPOWER AND LARGER ENGINES (EXCEPT VALVE-IN-HEAD ENGINES). Valve springs should be replaced when an engine is overhauled. Weak valve springs will spoil the best overhaul job.

CAP

VALVE SPRING COMPRESSOR TOOL PART NO. 670237A

Valve spring free length should be checked. Comparing one spring with the other can be a quick check to notice any difference. If a difference is noticed, carefully measure free lengths and strength of each spring. See specifications. Check valve spring free length, it should be 1.885'’ (47.879 mm). If both ends are not parallel, replace with new springs.

28

VALVE INSTALLATION. To reinstall valves, position valve caps and spring in the valve compartment. Valve spring free length should be checked and installed so the dampening coils are located opposite the keepers. INSTALL PIN Release valve spring tension to lock cap in place.

FREE LENGTH 1.885” (47.879 mm)

1/32” (.787 mm) FACE

45° MUST BE FLAT AND TRUE

FOR 8 HP AND LARGER (EXCEPT VALVE-IN-HEAD) SPRING MUST BE SQUARE

NO MARGIN

MARGIN

WRONG

WRONG STANDARD STEM DIAMETER SEE SPECIFICATIONS

STEM

OVERSIZE STEM DIAMETER SEE SPECIFICATIONS

MUST BE FLAT AND TRUE

IMPORTANT: GRIND FLAT TO OBTAIN CORRECT VALVE CLEARANCE DAMPENING COILS LOCATED CLOSER TOGETHER

DAMPENING COILS ON VALVE SPRINGS. The valve spring should be assembled so the dampening coil is located to the stationary end of the spring (opposite the cap and retainers).

VALVE SEATS. Valve seats are not replaceable. If they are burned or pitted, they can be recut using a Neway valve and seat cutter. Seats are cut to an angle of 46°. If the seat is over 3/64'’ (1.194 mm) wide after cutting, use a 30° cutter to narrow the face. ALWAYS DEGLAZE CYLINDER WALL

VALVE-IN-HEAD SPRINGS. Check valve spring free length, it should be 1-15/16'’ (49.225 mm) long. If both ends are not parallel, replace with new springs. SPRING MUST BE SQUARE

SEE SPECIFICATIONS SECTION FOR DIMENSIONS 46° ANGLE

VALVE SEAT IN CYLINDER FREE LENGTH 1.938” (49.225 MM)

DAMPENING COILS LOCATED CLOSER TOGETHER. POSITION TOWARD VALVE BOX.

VALVE SEAT CUTTING REQUIREMENTS. Cut valve seats to 46° and valve to 45°. See Specifications.

VALVE SEAT 46° FOR VALVE-IN-HEAD ENGINES

VALVE GRINDING. Valve grinding procedures are the same for all 8 horsepower and other engines. (Including overhead valve engines). See Chapter on specifications. Correct valve grinding procedures are essential to obtain a satisfactory result. Face and seat angles must be accurate and the surfaces must be smooth. A 1/32” (.787 mm) margin must be left on the valve head after refacing. The valve without a margin would burn and distort very rapidly. Use a “Vee” block and the flat side of a grindstone to grind valve clearance. The end of the stem must be flat and true or abnormal wear will occur.

EXHAUST

INTAKE VALVE SEAT IN HEAD

VALVE GUIDE DIMENSIONAL CHECK. Check dimensions per specification requirements, determine if valve guide clearance is beyond acceptable tolerance. If valve guide clearance is worn beyond tolerance, ream valve guide oversize and install 1/32'’ (.787 mm) oversize valve, or replace valve guides.

29

THIS SYMBOL POINTS OUT IMPORTANT SAFETY INSTRUCTIONS WHICH IF NOT FOLLOWED COULD ENDANGER THE PERSONAL SAFETY AND/OR PROPERTY OF YOURSELF AND OTHERS. READ AND FOLLOW ALL INSTRUCTIONS. VALVE GUIDE REMOVAL AND INSTALLATION INSTRUCTION FOR VALVE-IN-HEAD ENGINES. REMOVING THE OLD VALVE GUIDES 1. Submerge the head in a pan of oil so that both guides are covered with oil. 2. Heat oil on a hot plate until the oil begins to smoke. About 15 to 20 minutes. 375° (190°C) 400° (204°C). 3. When the oil begins to smoke, remove the head from the pan of oil with a pair of pliers. Drain excess oil. 4. Place head on the bed of an arbor press on parallels with the snap rings on the long ends of the guides facing down. 5. Use a 1/2'’(25.4 mm) diameter, 6'’ (152 mm) driftpunch and the arbor press to push valve guides out of the head. GUIDES HEAD OIL

HOT PLATE HEAT UNTIL OIL BEGINS TO SMOKE.

CAUTION - When locating the drift punch on the guides be sure to center the punch. DO NOT allow the punch to make contact with the head when pressing out the guides.

VALVE GUIDES 1/2” (12.7 mm) FLAT DRIFT PUNCH

CENTER PUNCH DRIFT ON VALVE GUIDE

30

INSTALLING NEW GUIDES NOTE For easy installation, the replacement guides should be placed in the freezer compartment of a refrigerator or on ice for no less than 30 minutes prior to installation. 1. Submerge head with guides removed in a container of oil so that both guide bores are covered with oil. 2. Heat oil on a hot plate until the oil begins to smoke. About 15 to 20 minutes. 3. When the oil begins to smoke, remove the head from the pan with a pair of pliers. Drain excess oil. 4. Place head, with gasket surface down, on a piece of wood, 6 x 12 inches (152 X 304 mm). 5. Remove the new guides from cold storage and install snap rings used for locating both valve guides. Insert the guides. It may be necessary to use a rubber or rawhide mallet to fully seat the guides to the snap ring depths in the head. DO NOT use a metal hammer head, or guide damage will result. 6. Allow head assembly to cool; recut both valve seats.

SECTION 2. CYLINDER HEAD CYLINDER HEAD TORQUE. For 8 H.P. and larger engines (except valve-in-head engines), make sure surfaces are clean, then place new head gasket on cylinder and position head.

BELLEVILLE WASHER CROWN SIDE UP

FLAT WASHER

Slide one belleville washer (crown toward bolt head) and one flat washer (sharp edge toward bolt head) over each bolt as shown in illustration. Insert the bolts in the head with the two shorter bolts in the position shown in the illustration. The two short bolts for positions 1 and 8 are 2'’ long (50.8 mm) and all other bolts are 2-1/4'’ long (57.15 mm). Tighten bolts evenly to 50 in. lbs. (5.6 Nm) torque. Increase torque evenly by 50 in. lbs. (5.6 Nm) until final torque of 200 in. lbs. (22.6 Nm) is attained in the following sequence: (See Figure) TORQUE IN NUMERICAL ORDER

HEAD BOLTS

BELLEVILLE WASHER (CROWN TOWARD BOLT HEAD)

FLAT WASHER (SHARP EDGE TOWARD BOLT HEAD) 7

2-1/4” (57.15 mm) BOLTS

6

4

2’ (50.8 mm) BOLTS

HEAD ASSEMBLY, TORQUE SPECIFICATIONS. Run engine for 30 minutes, allow to cool until head is cool to the touch and then retorque the bolts in the same sequence as described. (All except number “1” (25.4 mm) bolt which cannot be retorqued unless the rocker arm housing is removed.) 1 1-3/8” (34.925 mm) 4 1-3/4” (44.45 mm)

PUSH ROD TUBE “O” RINGS

1

2

9 5

3

8

6 1-3/4” (44.45 mm)

SPARK PLUG HOLE

Run engine for 15 minutes, allow to cool and then retorque the bolts in the same sequence as described above.

3 1-3/4” (44.45 mm)

5

1-3/8” (34.925 mm)

2 1-3/4” (44.45 mm)

TORQUE IN NUMERICAL ORDER

CYLINDER HEAD TORQUE FOR VALVE-IN-HEAD ENGINES. Slide one belleville washer (crown toward bolt head) and one flat washer (sharp edge toward bolt head) over each bolt as shown in illustration. Torque head bolts to 200 inch pounds (22.6 Nm) in 50 inch pound (5.6 Nm) increments. Tighten in numerical order. Note that head bolts marked 1 and 5 are 1-3/8'’ long (34.925 mm). Other bolts are 1-3/4'’ long (44.45 mm).

31

SECTION 3. BREATHER ASSEMBLIES The Breather is a sealed assembly. If it is defective, replace the entire assembly. The rubber tube on the outside is not part of the assembly. Install the breather with the drain holes toward the base of the engine. Always use a new gasket. The retaining screws must be tight. If oil is being pumped out the breather: 1. Check for excess speed. 2. Operating at excessive angles. 3. Loose oil filler cap. 4. Worn rings. 5. Excess blow-by. 6. Breather body installed up-side down. 7. Overfilled with oil. FOR 8 HP AND LARGER (EXCEPT VALVE-IN-HEAD)

DRAIN HOLES MUST BE TOWARD ENGINE BASE

BREATHER BODY AND VALVE

FOR VALVE-IN-HEAD ENGINES BREATHER BODY AND VALVE

BREATHER TUBE TROUGH TO BE INSTALLED AWAY FROM CARB SIDE OF ENGINE

32

CHAPTER 5. PISTON AND RINGS, CONNECTING RODS AND CRANKSHAFTS SECTION 1. PISTON AND RINGS PISTON AND RING DISASSEMBLY. Always remove ridge and carbon buildup before attempting to remove the piston and ring assembly from the cylinder. Always deglaze the cylinder when replacing the piston and rings. This must be done to allow the rings to seat. Make sure surfaces are clean, then place new head gasket on cylinder and position head.

RING GROOVE CHECK. Check the side clearance of the ring in the groove using a feeler gauge. If excessive, replace the piston. See Specifications. TOP PISTON LAND CLEARANCE PISTON

CYLINDER WALL

Always use a new head gasket if the cylinder head has been removed. 2nd COMPRESSION RING

POSSIBLE RIDGE BUILD UP AREA

1st COMPRESSION RING

SIDE CLEARANCE

3rd OIL CONTROL RING

PISTON DIAMETER MEASUREMENT. Check piston diameter on the bottom of the skirt. Check at 90° to center line of wrist pin hole. This is a cam ground piston and the diameter will not be the same when checked at another point. Pistons and rings may be available in either .010'’ (.254 mm), .020'’ (.508 mm), .030'’ (.762 mm) and .040'’ (1.016 mm) oversize.

RING AND WRIST PIN ASSEMBLY. Stagger the piston ring gaps 90° apart when installing piston and ring assembly in cylinder. The wrist pin retainers must be seated in the groove. Move the wrist pin if necessary. Failure to correctly seat the retainers may result in costly repairs. The wrist pin is a palm press fit (pressed in by hand with some resistance). If loose, check connecting rod for seizing. Replace piston and wrist pin if loose. RING GAPS

EXPANDER

CHECK PISTON DIAMETER AT THIS POINT

RING END GAP MEASUREMENT. Before installing the rings, insert each ring into the cylinder bore to check the end gap. This gap check should be made in a worn cylinder, a reconditioned cylinder and a new cylinder. An inverted piston should be used to push the ring into the cylinder to a point that would be the center of ring travel. The ring travel area will be the most worn area in a used cylinder. Insert the piston ring into the cylinder and place the top side of the piston on the ring to position the ring squarely in the bore; remove piston. Measure the end gap by inserting a feeler gauge between the ring ends. Check each ring using the same procedure.

WRIST PIN AND RETAINER

The end gap dimensions are shown in the specification division of this manual. If end gap is greater than the maximum specification, then the cylinder must be measured and perhaps bored oversize. If the end gap is too small, carefully remeasure the bore for undersize dimension and enlarge if necessary. 33

ARROWHEAD FEELER GAUGE

PISTON RING

MATCH MARKS RING CENTERED IN RING TRAVEL AREA

INVERTED PISTON TO POSITION RING SQUARELY IN CYLINDER

CHECK RING END GAP

PISTON RING INSTALLATION. Only correct piston ring installation will assure full power. Carefully note the ring sequence when removing the worn rings from the piston. Note especially the ring expander, as it may be found both behind the second (compression) ring and the third (oil control) ring. Although piston rings are installed correctly, they will not perform unless the piston and cylinder are reconditioned. Clean and check the ring grooves for wear. Deglaze the cylinder bore with a fine abrasive cloth; this will aid in the seating of the rings. When reinstalling the rings, note the marks on the first and second rings in dictating the top of the ring. Stagger the ring end gaps to prevent compression loss. Use plenty of service classification SF - SJ rated oil to lubricate all friction surfaces during engine reassembly.

INSIDE CHAMFER TO PISTON TOP

UNDER CUT (DOWN) EXPANDER LOCATED BEHIND THE SECOND COMPRESSION RING AND BEHIND THE OIL CONTROL RING

OFFSET PISTON INSTALLATION FOR OH180 VALVE OVERHEAD ENGINE. The connecting rod is assembled to the piston with match marks facing the mechanic and the arrowhead on the piston pointing to the right i.e., arrowhead facing the push rod tube area. 34

ARROWHEAD FACING PUSH ROD TUBES

SECTION 2. CONNECTING RODS When reinstalling a used connecting rod ALWAYS use new nuts on the bolts. These locking nuts will ensure that the torque will be retained when the connecting rod is replaced.

FOR ENGINE MODELS VH80 and VH100 ENGINE ROTATION

The connecting rod must be installed with the match mark facing out of the cylinder, toward the P.T.O. end of the crankshaft. This will ensure the correct positioning of the oil dipper. Install as illustrated.

OIL FEED HOLE

The heads of the through bolts must be seated tight against the machined shoulder on the connecting rod. Failure to check this may result in a false torque reading and premature failure. IMPORTANT Torque to correct specifications. 110 inch pounds (12.43 Nm).

OIL VAPOR PICK-UP HOLE

NOTE Before installing, clean the connecting rod bearing surfaces with a clean cloth. Rods are coated with lead which will slightly oxidize in storage, this oxidation must be removed. FOR ENGINE MODELS HH80, HH100 and HH120 and VALVE-IN-HEAD ENGINES. SLIP FIT WRIST PIN

OIL VAPOR PICK-UP HOLE

Torque to correct specifications 110-inch pounds (12.43 Nm). After initial torque use a drift and a hammer (13 oz.) (390 ml) and strike the rod bearing cap above each lock nut. This will seat the cap releasing some torque on the lock nuts. Retorque lock nuts to specifications.

THROUGH BOLT

INSTALL WITH MATCH MARK FACING OUT AND OIL DIPPER AS SHOWN

SPECIFICATION SECTION FOR BEARING SIZE AND NUT TORQUE

The vertical crankshaft 8 and 10 H.P. engines have a connecting rod with two lube holes. This rod is not interchangeable with the horizontal connecting rod. The above requirements listed for a horizontal crankshaft rod also apply to the vertical crankshaft engines connecting rod.

35

SECTION 3. CRANKSHAFTS CRANKPIN WEAR. Crankpins should be examined for wear, scoring, or out of-round. If any of these conditions are noted, replace the crankshaft. See specifications. Lubricate the crankpin generously before attaching the connecting rod. This will prevent damage during the initial run-in after reassembly. EXAMINE CRANKPIN FOR WEAR OR DAMAGE REPLACE IF DAMAGED

Note the chamfer tooth on the crankshaft gear. This tooth is used as a reference mark to be matched with the timing mark on the camshaft. The crankshaft gear is replaceable. Remove gear with a conventional puller after the roller bearing has been removed. The gear and the bearing may be removed simultaneously, but much difficulty may be encountered. Roller bearing must be heated before it is installed. NOTE: If a damaged gear is replaced, the mating gear should also be replaced. Example: If the camshaft is damaged and replaced, the crankshaft gear should be replaced. CHAMFER TOOTH CRANKSHAFT GEAR

The vertical VH80 and VH100 (without oil pump) oil slinger is located on the crankshaft. It is locked in position between the bearing and the crank gear and maintains that position due to a slot in the gear and a stamped bulge in the slinger. This alignment is necessary to direct the lubricant up into the engine at a closely engineered angle. Note the pickup trough and the stiffening rib. View B shows the trough alignment in correct relation to the crankcase journal. The slinger should not be incorrectly assembled 180° out of phase.

A

USE BEARING SEPARATOR AND PULLER TO REMOVE TAPERED BEARING

PTO TAPERED BEARING PRESS FIT, HEAT IN OIL TO INSTALL

REMOVE GEAR BY PLACING PULLER JAW UNDER GEAR

CRANKSHAFT GEAR IS PRESS FIT AND POSITIONED WITH CHAMFERED TOOTH AWAY FROM COUNTERWEIGHT

CRANKSHAFT GEAR INSTALLATION. Use an arbor press and suitable driver to press crankshaft gear into position. Keyway in crankshaft gear is to fit over gear pin and beveled tooth must face P.T.O. end of crankshaft. Crankshaft gear must fit tightly against shoulder. On engines equipped with Dyna-Static, the counterweight balance gear is installed between the crankshaft gear, spacer and the bearing. Keyway in counterbalance gear is to fit over gear pin and beveled tooth is in line with keyway.

B PLUNGER TYPE PUMP Some vertical VH100 engines use a plunger-type oil pump to circulate lubrication. The oil is pumped up through a hole in the camshaft to a passage allowing the crankshaft and parts to be lubricated. OIL SPRAY OPENING

CHAMFER AWAY FROM COUNTERWEIGHT AGAINST SHOULDER

PLUNGER REMOVE GEAR BY PLACING PULLER JAW UNDER GEAR

36

SUPPORT CRANKSHAFT AT COUNTERWEIGHT WHEN PRESSING ON GEAR

CHAPTER 6. CAMSHAFT, BEARINGS AND SEALS SECTION 1. CAMSHAFT CAMSHAFT GEAR TEETH WEAR. When servicing engines, check the camshaft at the points indicated by the asterisks in figure. Examine the gear teeth for wear and damage. See Specifications.

VALVE TIMING FOR ENGINE WITH HELICAL CUT GEARS.

NOTE: If a damaged gear is replaced, the mating gear should also be replaced. Example: If the camshaft is damaged and replaced, the crankshaft gear should be replaced. MECHANICAL COMPRESSION RELEASE. Clean the mechanism in a conventional parts cleaner and dry thoroughly. Individual component parts are not available as service replacement and cannot be obtained from the factory. New replacement camshafts with the compression relief mechanism are available.

CHAMFERED GEAR TOOTH

TIMING MARK

HOBBING HOLE

NOTE: When matching up helical gears, do so with a slight rotating motion of the crankshaft to the right. This way the teeth will slide together easier and the chamfered tooth and match mark will line up. *SEE SPECIFICATIONS SECTION FOR DIMENSIONS

VALVE TIMING. Match chamfered gear tooth on crankshaft with mark and hobbing hole on camshaft gear. C/S PTO END CHAMFERED TOOTH

CHAMFERED TOOTH MARK

HOBBING HOLE

37

SECTION 2. BEARINGS BEARING ASSEMBLY. The following figure illustrates the correct assembly of the tapered crankshaft bearings. The bearing at the flywheel end of the crankshaft seats in an adjustable bearing cup “A” in the cylinder. The bearing cup “B” supporting the P.T.O. end of the crankshaft is a press fit in the cylinder cover. Examine the bearing for wear, pitting, rust, alignment, and uneven wear of the rollers. If in doubt, replace to assure dependable trouble free service. BEARING

CYLINDER COVER “A”

“O” RING SHIM GASKET

STEEL WASHER IF REQUIRED

ROLLER BEARING

BEARING CUP “B”

BOTTOM ON SHOULDER

BEARING REMOVAL. Remove the bearing by securing a bearing separator between the bearing and crankshaft gear. Secure jaws of puller on the separator and draw bearing off shaft.

BEARING SEPARATOR

THIS SYMBOL POINTS OUT IMPORTANT SAFETY INSTRUCTIONS WHICH IF NOT FOLLOWED COULD ENDANGER THE PERSONAL SAFETY AND/OR PROPERTY OF YOURSELF AND OTHERS. READ AND FOLLOW ALL INSTRUCTIONS. BEARING INSTALLATION. Use only new bearings for installation on the crankshaft. Once a bearing has been removed it MUST be REPLACED as it becomes distorted and damaged while being removed. The new bearing may be installed on the crankshaft with pressure or heat. Heating the bearing is the preferred method. METHOD ONE - Using Heat. Heat the bearings in engine oil. Support the bearing off the bottom of the container as illustrated. Heat to approximately 300° F (148° C) or until oil smokes. Support the crankshaft in a vise. Hold the bearing carefully to prevent burns. Work rapidly to assure proper placement while the bearing is hot. The bearing must seat tight against the shoulder of the magneto end and tight against the crankshaft gear on the P.T.O. end. (If on a counterweight system, bearing should be against counterweight gear.) BEARING HELD OFF BOTTOM OF CONTAINER OIL LEVEL

NEW BEARING

38

METHOD TWO - Cold Bearing. The crankshaft MUST be supported between the counterweights when pressing on bearings. Use a driver to direct the pressure of an arbor press onto the inner race of the bearing when installing. The bearing must be seated tight against the shoulder of the crankshaft counterweight (on magneto end).

TAP CRANKSHAFT LIGHTLY TO SEAT IN PTO BEARING

This method may require a great amount of force, therefore, method one should be considered first.

PRESS THE BEARING CUP IN UNTIL TIGHT

Position the cylinder cover (magneto end), oil seal, and sleeve tool over the crankshaft and seat on the machined gasket surface. Insert a feeler gauge between the cover and cylinder, record the reading.

C/S MUST BE AT ROOM TEMPERATURE OR COOLER INNER RACE BEARING CONE ASSEMBLY BEARING MUST FIT TIGHT AGAINST SHOULDER

If there is no space between the cover and the machined gasket surface to allow insertion of the feeler gauge, use a .010” (.254 mm) metal spacer. The spacer fits between the bearing cup and inside surface of the cover. More than one may be used if required.

FEELER GAUGE MEASUREMENT

SUPPORT C/S AT THIS POINT WHEN PRESSING ON BEARING

BEARING CUP INSPECTION. The bearing cup should be examined for rust, pitting, scuffing, cracks or other damage. The bearing cup is removed by tapping the edge beneath the oil seal with a light hammer and flat punch. Press in a new cup until it bottoms on the shoulder. The bearing cup must be pressed in square, use an arbor press. BEARING CUP PRESSED INTO BOTTOM ON SHOULDER

REMOVE BY TAPPING ON INSIDE EDGE WITH FLAT PUNCH

NOTE: POSITION COVER AND MAKE MEASUREMENTS WITHOUT GASKETS OR “O” RING

Determine the gap between the cover and the machined surface on the cylinder, which should be from .001'’ - .007'’ (.025 mm.- .178 mm), in which case no shim gaskets will be required. However, if the space measures over .007: (.178 mm), follow the example below. Use of gaskets must be limited to a combined total of .010” (.254 mm) thick. Steel spacers must then be used to eliminate crankshaft end play. (Note: For VH100 with oil pump, see procedure on next page). Example:

OIL SEAL

PLACE SMALL AMOUNT OF GREASE ON INNER EDGE OF SEAL

PROCEDURES FOR CYLINDER COVER FIT. Reinstall cylinder cover using a new gasket and torque to specifications. After the cylinder cover is secured to correct torque specification, place the engine in a stand or device that will allow the P.T.O. (Power Take-Off) shaft to extend freely. Turn the crankshaft until the piston is at T.D.C. Tap the flywheel end of the crankshaft lightly with a mallet to seat the P.T.O. bearing. With either fingers or two screw drivers, press the bearing cup inward until tight.

.010'’

.254 mm clearance measured between cover and cylinder. If clearance is over .010” (.254 mm), use spacer. - .004'’ -.102 mm .001'’ to .007'’ (.025 - .1278 mm) allowed but use .004” (.102 mm) as the median. = .006'’ = .152 mm Shim thickness required + .006'’

.152 mm

Double above figure for thickness required to compensate for gasket compression

.012'’

.305 mm

total amount of shim gaskets required

(Continued on top next page) 39

When the space measures .001'’ (.025 mm) to .007'’ (.178 mm) no gaskets required, or if over .007'’ and shimmed with gaskets the end result is that there shall be no crankshaft end play. Shim gaskets are available in .004/.005” (.102/.127 mm) and .005/.007” (.127/.178 mm) thickness. NOTE: If clearance between cover and cylinder is over .007'’ (.178 mm) and gasket shims are not used, damage to the cylinder cover can result.

After the cylinder cover is secured to correct torque specification, place the engine in a stand or device that will allow the P.T.O. (Power-Take-Off) shaft to extend freely. DO NOT set engine on P.T.O. shaft or the correct crankshaft end play cannot be obtained. Turn the crankshaft until the piston is a T.D.C. Tap the flywheel end of the crankshaft lightly with a mallet to seat the P.T.O. bearing.

TAP CRANKSHAFT LIGHTLY TO SEAT IN PTO BEARING PRESS THE BEARING CUP IN UNTIL TIGHT

Insert an oil seal in the cover. Position the .010 (.254 mm) spacer, if required. Position the shim gaskets (if required) and place the cover on the cylinder. Use an oil seal sleeve to protect the oil seal. Secure the cover with the hex head bolts and TORQUE. See Specifications. Rotate the crankshaft and test for freedom of movement. There shall not be any crankshaft end play. The only exception is the VH100 with oil pump.

With either fingers or two screwdrivers, press the bearing cup inward until tight. NOTE: When measuring for crankshaft end play be sure shim gaskets and O rings are removed. Position the cylinder cover (magneto end), oil seal, and sleeve tool over the crankshaft and seat on the machined gasket surface. Insert a feeler gauge between the cover and cylinder; record the reading.

Knocking noise in an engine may at times be traced to excessive radial crankshaft play. If this is noted, review the cover shim gaskets. Correct by adding or removing as required.

FEELER GAUGE

COVER

POSITION COVER WITHOUT GASKETS SHIM GASKETS

“O” RING

.010 (.254 mm) SPACER AS REQUIRED

Newer model engines have an “O” ring which seals between the shim gaskets and the chamfer on the crankcase. END PLAY ADJUSTING PROCEDURES FOR VH100 WITH OIL PUMP

40

If space does not exist between the cover and the machined gasket surface to allow insertion of the feeler gauge use a .010 (.254 mm) metal spacer. The spacer fits between the bearing cup and inside surface of the cover. More than one may be used if required.

After determining the gap between the cover and the machined surface on the cylinder, determine the shim thickness as follows to result in the required .002 - .007 (.051 - .178 mm) crankshaft end play. Example: .003'’

.076 mm

- .002'’ .005'’

.051 mm .127 mm

+ .003'’

.076 mm

.008'’

.203 mm

The bearing cup should be examined for rust, pitting, scuffing, cracks or other damage. BEARING CUP PRESSED INTO BOTTOM ON SHOULDER

REMOVE BY TAPPING ON INSIDE EDGE WITH FLAT PUNCH

Clearance between cover and cylinder Required end play Shim thickness required Add half above figure for thickness required to compensate for gasket compression Use shim gaskets that total this amount.

Shim gaskets are available in .004/.005” (.102/.127 mm) and .005/.007” (.127/.178 mm) thickness.

OIL SEAL

PLACE SMALL AMOUNT OF GREASE ON INNER EDGE OF SEAL

The bearing cup is removed by tapping the edge beneath the oil seal with a light hammer and flat punch. Press in a new cup until it bottoms on the shoulder. The bearing cup must be pressed in square, use an arbor press. Reinstall cylinder cover using a new gasket and torque to specifications.

Insert an oil seal in the cover. Position the .010 (.254 mm) spacer if required. Position the shim gaskets and O ring and place the cover on the cylinder. Use an oil seal sleeve to protect the oil seal. Secure the cover with the hex head bolts and TORQUE to specifications. Rotate the crankshaft and test for freedom of movement, end play and radial play. Knocking noise in an engine may at times be traced to excessive radial crankshaft play. If this is noted, check the cover shim gaskets. Correct by adding or removing as required. COVER

SHIM GASKETS

.010 (.254 mm) SPACER AS REQUIRED

41

SECTION 3. SEALS Use an oil seal protector when removing covers from crankshaft. See Chapter 11 of Mechanics Manual under “Tools”, using tool as shown. Remove the cylinder cover at either the P.T.O. or flywheel end. Drive the seal out of the cylinder cover from the inside out. Install a new seal. Use new gaskets. Use the seal protector when replacing the cover.

SEAL PROTECTORL DRIVE DOWN WITH HAMMER UNTIL SEAL IS FLUSH WITH COVER

Ô

OIL SEAL MUST BE SQUARE IN BORE

SEAL DRIVER DRIVE OIL SEAL FLUSH TO .025 (.635 mm) BELOW SURFACE

OIL SEAL SEAL PROTECTOR/ INSTALLER

CYLINDER COVER

C/S SEAL MAG. END

BEARING OR CYLINDER COVER (Removed from engine) USE THIS METHOD TO DRIVE OIL SEALS FLUSH AND SQUARE INTO THE SEAL RECEPTACLE

DRIVE OIL SEAL FLUSH TO .025 (.635 mm) BELOW SURFACE

OIL SEAL MUST BE SQUARE IN BORE

C/S SEAL PTO END

Remove the covers before installing the oil seal. The crankshaft cannot protrude while the seal is being installed. Lay the cover on a flat clean surface. Use a seal driver and the correct seal installer to drive the seal into position. (See Chapter 11, Technician’s Manual for tools). Place the seal onto the seal protector/ installer and then over the bore, center the driver over the seal and drive the seal into position with a hammer. USE A SEAL PROTECTOR EVERY TIME THE OIL SEAL IS PUT ONTO OR PULLED OFF OF THE CRANKSHAFT.

42

CHAPTER 7. DYNA-STATIC ® BALANCING SYSTEM TECUMSEH DYNA-STATIC® BALANCING SYSTEM. Dyna-Static® Tecumseh’s Balancing system for horizontal crankshaft 10, 12, 14, 16 and 18 H.P. Dyna-Static ® operates by means of a pair of counterweighted gears driven off the crankshaft to counteract the unbalance caused by the counterweights on the crankshaft. The exterior distinguishing feature of an engine equipped with a balance system is the “deep-dished” side cover. This cover contains the counterbalance gears and shaft. Tecumseh Dyna-Static® balancing system also utilizes a helical (angle) cut set of gears consisting of a crankshaft gear and two counterbalance gears. There are two sets of helical counterweight assemblies. The difference between the two assemblies is the counterweight mass. They cannot be distinguished by size. Check Parts Manual or Microfiche for correct counterweight set. The helical cut gear assemblies may be interchanged with the regular cut gear assemblies, but only if all three gears (crankshaft gear and two counterweight gears) are interchanged as a set.

ALIGNING THE COUNTERWEIGHTS (Side-by-Side counterweights) This view of the side cover is from the outside showing the pipe plugs which plug the alignment holes during normal operation. NOTE: Be careful when installing the cylinder cover that the counterweight balance gears remain in alignment. Remove pipe plugs from flange, assemble flange to cylinder making sure the slots stay in hole. Slots may have to be moved either way with punch or screwdriver to mesh gears. If you can see any part of slots in holes after assembled, it is correctly assembled. Reinstall pipe plugs. The important thing is to keep the counterweight gears perfectly aligned on the crankshaft gear. Any misalignment of these gears can cause vibration. Insure also that the governor rod assembly is correctly placed. T.D.C.

PIPE PLUGS

TOP & BOTTOM COUNTERWEIGHTS On some production models the counterweight balancing gears are placed top and bottom of the crankshaft. The gears mesh with the driver gear on crankshaft when the piston is at T.D.C. and the gear weights are down as shown. NOTE: If a damaged gear is replaced, the mating gear should also be replaced. On some production models the counterbalancing gears are placed top and bottom of crankshaft.

Example: If the camshaft is damaged and replaced, the crankshaft gear should be replaced. T.D.C.

PIPE PLUGS

43

Positioning of helical-type gears is the same as shown in the figure below. PISTON AT T.D.C.

PISTON AT T.D.C.

SPACER

On current production models, the counterweight balancing gears are placed top and bottom of the crankshaft. The position dimension is the same as for side-by-side counterweight models.

COUNTERWEIGHT FULL BOTTOM COUNTERWEIGHT SPACER FULL BOTTOM

REGULAR CUT GEARS

HELICAL CUT GEARS

1.7135 (43.523 mm) 1.7185 (43.650 mm)

CRANKSHAFT GEAR ALIGNMENT NOTE: Whenever the camshaft gear is damaged, the crankshaft gear should be replaced. Note the chamfer tooth on the crankshaft gear. This tooth is used as a reference mark to be matched with the timing mark on the camshaft. On engines equipped with Dyna-Static, the counterbalance weight drive gear is installed between the crankshaft gear and the bearing with a spacer. The crankshaft gear and the counterbalance weight drive gear are replaceable. Remove gears with a conventional puller after the roller bearing has been removed.

BEARING REPLACEMENT. If replacement of caged needle bearings is required, press the replacement in flush to .015 (.381 mm) below inside surface, use tool No. 670210. This figure shows the counterweight side and the slot cut for the tool alignment. PRESSED CAGED BEARING IN FLUSH TO .015 (.381 mm) BELOW SURFACE

SLOT FOR ALIGNMENT TOOL

The figure below shows one counterbalanced driven gear removed from the shaft. Each counterbalanced shaft is pressed into the cylinder cover so that a dimension of 1.7135'’(43.523 mm) to 1.7185'’ (43.650 mm) exists between the side cover boss and the end of the shaft.

1.7135 (43.523 mm) 1.7185 (43.650 mm)

44

CHAPTER 8. IGNITION SYSTEMS, CHARGING SYSTEMS BATTERY SERVICE and ELECTRICAL CONTROL PANELS SECTION 1. IGNITION SYSTEMS SOLID STATE SYSTEM IGNITION SERVICE. a.

General. Follow through the checks and explanations below, if everything checks ok, then replace the ignition unit. The parts of the system are: 1. 2. 3. 4. 5.

b.

c. d.

Ignition coil. Flywheel. Ignition unit. High tension lead. Spark plug.

e. Air Gap Checks. Adjust the system so that a .006/.010'’ (.152/.254 mm) clearance exists between the ignition unit and the long trigger pin in the flywheel. To adjust, loosen the retaining screw and move the unit to find the proper gap. Follow through the checks and explanations below, if everything checks ok, then replace the ignition unit. REMOVAL OF FLYWHEEL TRIGGER PINS

Spark Plug Check. Test ignition by using a test plug or hold the high tension lead terminal 1/8-in.(3.175 mm) from the spark plug. Crank the engine over rapidly. If a good blue spark jumps the gap, the ignition system is functional.

Removal of damaged pins. CAUTION: Pins must not be reused. Use care not to damage flywheel. Never hammer on a flywheel as permanent damage to the magnets could result.

If no spark is present, make the following checks: c through f.

Use vise-grip pliers to remove the pins. If the pins are very tight, hammer lightly on the pliers at the same time pulling on the pins. Do not twist. If a vise is used to secure the flywheel, use care not to damage.

Check high tension lead for a ground or an open circuit in the ignition unit. Check coil lead and connection to ignition unit terminal.

CAUTION: If the engine won’t run, after previous acceptable performance, check the equipment ignition switch. 1/8” (3.175 mm) Ô Ô

HIGH TENSION LEAD

1/8” (3.175 mm) GROMMET IGNITION UNIT IGNITION UNIT TERMINAL

INSTALLATION OF NEW TRIGGER PINS. 1. Position the flywheel with the fins on a flat surface. Holes toward you - See Figure. 2. Coat shaft of pins with Loctite. CAUTION: Do not use a hammer to drive in pins. 3. Use masking tape to cover wide-mouth pliers (channel lock type) and press fit the short pin into hole on right. Fit the long pin on the left. 4. Pins must be pressed up to pin shoulder. Wipe away any excess Locktite. 5. The magneto air gap must now be adjusted to correct for any changes in trigger pin height.

SET GAP .006” .152 mm .010” .254 mm LONG TRIGGER PIN SHORT TRIGGER PIN SET GAP .006” .152 mm .010” .254 mm

LONG TRIGGER PIN SHORT TRIGGER PIN

.187 (4.750 mm)

HIGH TENSION LEAD

.250 (6.35 mm)

SHORT PIN

LONG PIN

10 and 20 AMP ALTERNATOR SYSTEMS

45

f.

Coil Lead on 10 Amp Alternator Systems. Remove the coil lead from the ignition unit terminal. Attach the leads from a standard ohmmeter to the lead eyelet and to ground to check series resistance of the ignition generator coil.

RETAINING SCREWS

1. If resistance is below 400 ohms, replace the stator assembly which includes the coil. NOTE: The ignition generator coil cannot be replaced separately. 2. If coil resistance is above 400 ohms, replace the ignition unit. CAUTION: Before replacing Ignition Unit, meter ignition cutoff circuit in the switch for a “short”, allowing battery current to burn out the ignition unit.

STATOR AND COIL ASSEMBLY

FOR 10 AMP IGNITION SYSTEM

RETAINING SCREWS

Remove the switch and connect the leads from a continuity meter to the battery lead terminal and the ignition ground terminal. Actuate the switch in various positions to see if continuity exists. Any continuity indicates a bad switch. When replacing a switch be sure that the lead and terminal do not short through the equipment frame. STATOR AND COIL ASSEMBLY

FOR 20 AMP IGNITION SYSTEMS

OHMMETER

TO GROUND

LEAD EYELET

COIL LEAD

CONNECTIONS ARE THE SAME FOR 8 H.P. AND LARGER AND VALVE-IN-HEAD ENGINES g. Coil Lead on 20 Amp Alternator Systems. Remove the coil lead from the ignition unit terminal. Attach leads from a standard ohmmeter to the lead eyelet terminal and to ground to check series resistance of the ignition generator coil. If coil resistance is between 115 ohms and 171 ohms, replace the ignition unit. CAUTION: Before replacing Ignition Unit check the ignition cutoff circuit in the switch, for a “short” allowing battery current to burn out the ignition unit. Remove the switch and connect leads from acontinuity meter to the battery lead terminal and the ignition ground terminal. Actuate the switch in various positions to see if continuity exists as shown on the meter. Any continuity indicates a bad switch. When replacing the switch be sure that the lead and terminal do not short through the equipment frame. 46

SOLID STATE IGNITION ALTERNATOR TYPE).

SYSTEM

(NON-

SPADE CONNECTOR FOR 20 AMP IGNITION UNIT

CAUTION: Do not attempt to crank engine with the primary wire of the transformer disconnected. Also do not allow the primary wire of the transformer to be grounded or arc. A broken wire causing an open circuit to or in the transformer can also cause permanent damage. See Step 2.

CHARGING COIL

1. Preliminary Tests GROUND TERMINAL

Spark Test . . .Check for spark. Perform the following visual tests: HIGH TENSION LEAD . . .Inspect for cracks or indications of arcing. Replace the transformer if a questionable lead is found. LOW TENSION LEADS . . .Check all leads for shorts. Check ignition cut-off lead to see that unit is not grounded out. Repair leads if possible, or replace. FLYWHEEL . . .Check magnets for strength. Check key and keyway. Be sure that the key locks the flywheel to the crankshaft. 2. After the above visual checks are made the transformer and solid state components can be checked using a Merc-O-Tronic, Graham-Lee or similar tester. NOTE: Before using parts for tests, be sure any problem which caused replacement is corrected first. 3. When testers are not available... Use new replacement parts as test for possible failed parts. SOLID STATE STATOR - Replace and test for spark. Time the magneto by turning counterclockwise as far as it will go. Tighten retaining screws to 5-7 foot pounds (6.8 - 12.4 mm).

HIGH TENSION LEAD

PULSE TRANSFORMER

IGNITION CUT-OFF LEAD

IGNITION UNIT LOW TENSION LEAD

USED WITH 20 AMP SINGLE MAGNET FLYWHEEL

TO C. D. I. MODULE

EXCITER COIL

TO SHUT OFF SWITCH SCHEMATIC DIAGRAM CHARGE COIL IGNITION BLOW-OUT PROTECTION NOTE: THERE MUST BE AN ELECTRICAL CONTINUITY FROM EITHER LEAD TO BASE PLATE, BUT NO CONTINUITY IN THE REVERSE DIRECTION OR BETWEEN LEADS.

STATOR PLATE ASSEMBLY (20 AMP SYSTEM). Previous tests also apply, except for the following: 1. Test the ignition unit first. If good, remove flywheel and check coil for continuity. 2. Determine if correct flywheel is used, if previously replaced. The flywheel used for a 20 amp system is not compatible with flywheel used on a 10 amp systems. 3. The stator cannot be turned once secured with stator bolts.

PRIMARY SET GAP .006 WIRE .010 (.152 mm) (.254 mm) LONG TRIGGER PIN TIME

NEW NON-ALTERNATOR SOLID STATE STATOR

SHORT TRIGGER PIN FLYWHEEL

PRIMARY WIRE

MAGNETO IGNITION COIL

ONE TYPE OF NON-ALTERNATOR IGNITION FOUND ON 8 HP AND LARGER ENGINES

ONE TYPE OF NON-ALTERNATOR IGNITION FOUND ON VALVE-IN-HEAD ENGINES

47

SECTION 2. CHARGING SYSTEMS PRECAUTIONS CAUTION: Electrical components of the 10 amp alternator system are similar to the 20 amp alternator system. Use care not to interchange electrical components; severe damage will result. A. Do not connect battery to cables in wrong polarity. This will cause regulator-rectifier damage. B. Break continuity between the regulator-rectifier unit and battery when using a remote charger on the battery. This will eliminate damage to the regulator-rectifier if polarity is reversed. C. Disconnect wiring harness at regulator-rectifier before using arc welder on equipment.

Do not force or modify connectors. Test values are identical to original 20 amp alternator system. PRE-SERVICE CHECKS a. Check for a good ground between regulator-rectifier and mounting. b. Check for poor connections or broken wires. c. Check the fuse. NOTE: Battery voltage must be above 6 volts for the regulator to be activated. This applies only to the 20 amp system with regulator-rectifier in housing. MAGNETO SHUT OFF LEAD GREEN

D. Do not short alternator leads together.

VIEW A A

E. When normally running the engine DO NOT disconnect the lead to the battery. NOTE: Only when testing the D.C. output, should the D.C. output lead be disconnected from the battery.

VIEW B B D.C. OUTPUT LEAD RED

SOLID STATE RECTIFIER REGULATOR MOUNTED ON ENGINE (PROVIDED BY TECUMSEH)

STARTING MOTOR

RED

GREEN GROUND IS THRU THE MOUNTING BOLTS

SOLENOID FUSE LIGHT ETC.

F. If wiring must be replaced in any part of the circuitry, be certain the same size (gauge) wire is used. Wire between the battery to the starter motor must be a minimum of No. 6 gauge. For the 20 amp alternator system the charge circuit uses No. 14 gauge wire. Most of the remaining portion of the circuitry will be No. 18. Newer 20 amp systems are distinguished by the regulator-rectifier installed in the blower housing. Connectors are not interchangeable with connectors on the external type regulator-rectifier 20 amp system.

ALL INDICATED GROUNDS ARE TO ENGINE ALL GROUND CONNECTIONS TO BE CLEANED TO A BRIGHT FINISH SAFETY STANDARDS MAY REQUIRE AN OVER LOAD PROTECTION DEVICE ON BATTERY FEED SIDE OF SWITCH IN ADDITION TO OR IN LIEU OF FUSE SHOWN ON DIAGRAM BATTERY RECOMMENDED MIN SIZE 32 AMPERE HOUR LARGER SIZE REQUIRED FOR COLD TEMPERATURE OPERATION 50 AMPERE HOUR

BATTERY

SWITCH AMMETER

KEY SWITCH

20 AMP. ALTERNATOR SYSTEM

GROUND IS THRU MT’G BOLTS MAGNETO GROUND

STARTING MOTOR

A.C.

MAG. GROUND (GREEN LEAD)

A.C. (YELLOW LEADS)

STARTING MOTOR A.C.

A.C.

SOLENOID

A.C.

VIEW A A

GROUND IS THRU THE MOUNTING BOLTS

SOLENOID

LIGHT ETC.

BATTERY

SWITCH

GROUND IS THRU MT’G SCREWS

B+

LIGHT ETC. SWITCH BATTERY

GROUND IS THRU MT’G SCREWS

BATTERY

SOLID STATE RECTIFIERREGULATOR

A.C. AMMETER

30 AMP FUSE

KEY SWITCH AMMETER KEY SWITCH OFF - MAGNETO TO GROUND ALL OTHERS OPEN. RUN - MAGNETO OPEN, RECTIFIER BATTERY, BATTERY TO LIGHTS. START - BATTERY TO SOLENOID.

10 AMP. ALTERNATOR SYSTEM 48

VIEW F F

OFF - MAGNETO TO GROUND, ACCESSORY TO GROUND ALL OTHERS OPEN. RUN - RECTIFIER TO BATTERY, ACCESSORY TO BATTERY. ALL OTHERS OPEN. START - BATTERY TO SOLENOID. ALL OTHERS OPEN.

20 AMP. ALTERNATOR SYSTEM

Before performing the following tests see page 48, A through F. TEST NO. 1 (NO CHARGE TO BATTERY) NOTE: Tests must be followed in their order of listing. EXAMPLE: Test No. 1 must be completed before proceeding to Test No. 2. Replace any defective part.

10 AMP ALTERNATOR TEST B+ TERMINAL WIRE

Disconnect B+ at battery lead (NOTE: Keep test to a minimum with B+ wire disconnected from the battery) and check D.C. voltage between B+ regulator lead and case:

D.C. VOLTMETER LEADS

1. 2500 RPM 13.0 volts min. 3000 RPM 16.0 volts min. 3600 RPM 20.00 volts min.

1. System okay. Check for defective ammeter.

2. If less than above voltages but greater than 0 volts.

2. Check for possible defective regulator-rectifier.

3. If 0 volts at any above speeds.

3. Check for defective stator or regulator-rectifier.

REGULATOR-RECTIFIER

TEST NO. 2 (NO CHARGE TO BATTERY) With battery connected, check B+ to ground voltage with D.C. voltmeter. 1. 2500 RPM: If 11.0 volts or higher place load (head lights) on battery to reduce battery voltage to 10.0 volts. 3000 RPM: If 20.0 volts or higher place load (head lights) on battery to reduce battery voltage to 11.0 volts. 3600 RPM: If 13.5 volts or higher place load (head lights) on battery to reduce battery voltage to 12.0 volts.

A.C. VOLTMETER LEADS

a. If charge rate increases.

System okay. Battery was charged fully.

b. If charge rate does not increase.

Check for defective stator or regulator.

TEST NO. 3 (NO CHARGE TO BATTERY) Disconnect plug from regulator-rectifier and test A.C. voltage at plug. 1. 2500 RPM: Voltage reads less than 16 volts.

1. Defective stator

2. Voltage reads over 16 volts.

2. Defective regulator-rectifier.

3. 3000 RPM: Voltage reads less than 19 volts.

3. Defective stator

4. Voltage reads over 19 volts.

4. Defective regulator-rectifier.

5. 3600 RPM: Voltage reads less than 24 volts.

5. Defective stator

6. Voltage reads over 24 volts.

6. Defective regulator-rectifier. 49

TEST NO. 4 (BATTERY ALWAYS CHARGING AT HIGH RATE) Check B+ to ground voltage with D.C. voltmeter. 1. 2500 RPM: Voltage over 14.7 volts. 1. Regulator not functioning. 2. 3000 RPM: Voltage over 14.7 volts. 2. Regulator not functioning. 3. 3600 RPM: Voltage over 14.7 volts. 3. Regulator not functioning. 4. 2500 RPM: Voltage under 12.0 volts. 4. Battery charge low. Alternator and Regulator System okay. Check battery. 5. 3000 RPM: Voltage under 13 volts.

5. Battery charge low. Alternator and Regulator System okay. Check battery.

6. 3600 RPM: Voltage under 14.7 volts. 6. Battery charge low. Alternator and Regulator System okay. Check battery. TEST NO. 5 (BATTERY BOILING OR FUMING) Check B+ to ground voltage with D.C. voltmeter. 1. If over 14.7 volts.

1. Regulator not functioning.

Visual check for overfilling.

Overfilled battery may appear to fume due to expansion.

20 AMP. ALTERNATOR TESTS Before performing the following tests, see page 48, A through F. TEST NO. 1 (NO CHARGE TO BATTERY) TERMINAL WIRE

NOTE: Tests must be followed in their order of listing. EXAMPLE: Test No. 1 must be completed before proceeding to Test No. 2. Replace any defective part. D.C. VOLTMETER LEADS

RECTIFIER-REGULATOR

With battery connected check B+ to ground voltage with D.C. voltmeter. 1. Place load (head lights) on battery to reduce battery voltage to below 12.5 volts. (This may take a few minutes.) 2. Start engine. Run at 2500 RPM, 3000 RPM and 3600 RPM with same load as above. a. If voltage increases.

TEST SET-UP ON 20 AMP SYSTEMS WITH EXTERNAL REGULATOR-RECTIFIER

b. If voltage does not increase.

a. System okay - Battery was charged fully. b. Check for defective stator or regulator system. Tests No. 2 and No. 3.

GREEN YELLOW

YELLOW

YELLOW

YELLOW GREEN

RECT. - REG.

RED

GREEN FUSE

RED

SWITCH B R M

TEST SETUP ON NEW 20 AMP. SYSTEMS WITH RECTIFIERREGULATOR IN BLOWER HOUSING. TEST VALUES SAME AS ORIGINAL 20 AMP. SYSTEM.

50

BATTERY

D.C.VOLTMETER

TEST NO. 2 (NO CHARGE TO BATTERY) Disconnect plug from regulator and test AC voltage at plug. 1. 2500 RPM: Voltage reads less than 1. Defective stator. 32 volts. 2. Over 32 Volts.

2. Defective regulator See Test No.3.

3. 3000 RPM: Voltage reads less than 3. Defective stator. 38 volts. 4. Over 38 volts.

4. Defective regulator See Test No.3.

5. 3600 RPM: Voltage reads less than 5. Defective stator. 45 volts. A.C. VOLTMETER LEADS

6. Over 45 volts

6. Defective regulator See Test No.3.

GREEN YELLOW

YELLOW A.C.VOLTMETER

YELLOW YELLOW GREEN RED RECT. - REG.

SWITCH R B

GREEN FUSE

RED

M

TEST SETUP ON NEW 20 AMP. SYSTEMS WITH RECTIFIERREGULATOR IN BLOWER HOUSING. TEST VALUES SAME AS ORIGINAL 20 AMP. SYSTEM.

D.C. AMMETER

BATTERY

TEST NO. 3 (LOW CHARGE TO BATTERY) Check current output with D.C. ammeter connected in series from B+ of regulator to positive side of battery. 1. 2500 RPM @ 12.5 volts load current reads less than 13 amps.

1. Defective stator.

2. 3000 RPM @ 12.5 volts load. current reads less than 15 amps

2. Defective stator.

3. 3600 RPM @ 12.5 volts load current reads less than 17 amps.

3. Defective stator.

GREEN YELLOW

YELLOW YELLOW

D.C.VOLTMETER

YELLOW GREEN RECT. - REG.

GREEN RED FUSE

SWITCH B R

RED M TEST SETUP ON NEW 20 AMP. SYSTEMS WITH RECTIFIERREGULATOR IN BLOWER HOUSING. TEST VALUES SAME AS ORIGINAL 20 AMP. SYSTEM.

BATTERY

51

TEST NO. 4 (BATTERY ALWAYS CHARGING AT HIGH RATE) Check B+ to ground voltage with D.C. voltmeter. 1. If over 14.8 volts at 2500 RPM, 3000 RPM, and 3600 RPM.

1. Regulator is not functioning.

2. If under 14.4 volts @ 2500 RPM. @ 3000 RPM. @ 3600 RPM.

2. Battery charge low. Alternator okay, check battery.

D.C. VOLTMETER

TEST NO. 5 (BATTERY BOILING OR FUMING). Check B+ to ground voltage with D.C. voltmeter. 1. If over 14.8 volts.

1. Regulator not functioning.

Visual check for overfilling.

TEST SETUP ON NEW 20 AMP. SYSTEMS WITH RECTIFIERREGULATOR IN BLOWER HOUSING. TEST VALUES SAME AS ORIGINAL 20 AMP. SYSTEM.

GREEN YELLOW

D.C.VOLTMETER

YELLOW YELLOW

Overfilled battery may appear to fume due to expansion.

YELLOW

GREEN RED

GREEN SWITCH R B

RECT. - REG.

FUSE RED M

52

BATTERY

SECTION 3. BATTERY SERVICE BATTERY POWER DECREASES WHILE ENGINE CRANKING POWER REQUIREMENT INCREASES WITH FALLING TEMPERATURE

100%

80°F (26oC) 100%

68%

32°F (0oC) 165%

30%

46%

0°F (-18oC) 250%

-20°F (-30oC) 350%

greater rating is recommended. BATTERY CONDITION. While the battery is built to satisfactorily withstand the conditions under which it will normally operate, excessive mechanical abuse leads to early failure. The following points are important to properly install a battery: 1. Be sure the battery carrier is clean and that the new battery rests level when installed. 2. Tighten the hold-down evenly until snug. Do not draw down tight enough to distort or crack the battery case. 3. Be sure the cables are in good condition and the terminal clamps are CLEAN. Grease battery terminals lightly with petroleum jelly before attaching cable clamps. Make sure the ground cable is CLEAN and TIGHT at the engine block or frame.

BATTERY CHECK. Because the battery is part of two circuits starting, ignition and charging (in the ignition circuit, only in switch starting units) the battery should be checked first.

4. Check polarity to be sure battery is not reversed with respect to the generating system.

If battery has a shorted cell, overcharging can result, and the regulator rectifier may appear to be at fault. If a cell has an open or high resistance connection, cranking motor operation will be affected, but replacing the cranking motor will not cure the trouble. If the battery is badly sulphated, consistent low gravity readings, slow cranking, and possible poor ignition performance can be experienced during starting.

CAUTION: The charging process will chemically liberate oxygen and hydrogen gasses. This highly flammable mixture may be dangerous if ignited. Disconnect ground terminal first to prevent arcing at the positive terminal.

BATTERY SIZE RATIO: AMPERAGE TO TEMPERATURE. It is always good practice to select a replacement battery of an electrical size at least equal to the battery originally engineered for the vehicle by the manufacturer. Battery power decreases while the need for engine cranking power increases with falling temperature. Subzero cold reduces battery capacity of a fully charged battery to 30% of its normal power and at the same time increases cranking load beyond the normal warm weather load. Hot weather will place excessive electrical loads on batteries. Difficulty in starting may occur when cranking is attempted shortly after a hot engine has been turned off. If the capacity rating for the original equipment battery cannot be determined, a 32 amp or greater rated replacement battery would be sufficient. IMPORTANT: For operation at colder temperatures, a 50 amp or

5. Connect “ground” terminal of the battery last, to avoid “short” circuits which will damage the battery.

BATTERY PRECAUTIONS. If a battery is not used for a long period of time, it is advisable to remove the terminal connections to prevent a slow discharge. On some units there is an ON-OFF switch to cut the battery out of the circuit when not in use. Be careful when replacing battery connections. A reversal of polarity can cause damage to the regulatorrectifier. BATTERY MAINTENANCE: (Acid-Type) Check water level periodically to determine that the top of the battery plates are covered. Never overfill ! Whenever possible, add only distilled water. If not available, use water with the lowest possible mineral content. Hard water will cause an accumulation of calcium deposits. Never add water to a battery at below freezing temperatures unless the water has been thoroughly mixed with electrolyte first. This may be done by operating the engine for about 4 hours. Do not add acid unless it has been lost. Only water in the sulfuric acid solution is normally evaporated through normal usage. If the solution has been lost by spilling, add acid so there is not more than a 10 to 1 ratio of acid to water. 53

Check to determine if the vent holes in the caps are open. In normal usage the battery casing may be partially covered with a white powder. Clean such areas with a solution of 1 part bicarbonate of soda to 4 parts water. Use care to prevent solution from entering battery cells. If battery terminals show corrosion, remove battery connections carefully. Do not twist or use unnecessary force to remove from battery. Brighten battery posts and connections. Coat battery posts and terminal connections with petroleum jelly and replace. (Never hammer on battery posts!) TESTING THE BATTERY. Voltage Check of AcidType Battery (12 volt). NOTE: Do not attempt to measure individual cell voltage by “jabbing” a voltmeter probe through the battery cover. **Time Required to Charge Battery at 5 Amp Hour Rate

*Specific Percentage of 24 Amp Gravity Charge in Battery Hours

32 Amp Hours

50 Amp Hours

1.140

Discharged

5 hours

7 hours

10 hours

1.170

25% Charged

4 hours

5 hours

8 hours

1.200

50% Charged

3 hours

5 hours

4 hours

1.230

75% Charged

1 hours

2 hours

3 hours

1.260

100% Charged

*This may vary from battery manufacturer ’s specifications. **These are approximations. Time may vary due to cell conditions, battery construction, heat, etc. NOTE: The approximate charging time can be calculated by dividing the Amp-Hour rate of the battery by the Amp-Hour charging rate of charger. (For example: a 55 amp-hour battery on a 5 amp hour charger will take about 11 hours to charge.) The slower charging rate, the easier it is on the battery, and the more thoroughly you will dissolve the sulfate that has collected. Generally a charge rate of 5-7 amps per hour is ideal. 1. Using a battery tester voltmeter, hook up the battery and adjust for 3 times the amp-hour rating of the battery. 2. After 15 seconds (no longer) read the voltmeter. If the voltage is over 9.6 volts check the specific gravity. If reading is below 1.230, charge the battery.

54

SPECIFIC GRAVITY CHECK. Use a hydrometer to determine that there is at least 75% charge in the battery. CAUTION: Electrolyte solution contains sulfuric acid. Handle with care since spilled liquid is very corrosive to skin and clothing. Use protective eye cover. 1. Remove caps and check water level, if below battery plates, add water and recheck battery after the water has mixed with the electrolyte after about 4 hours use with engine charge. 2. Put the hydrometer into battery and draw electrolyte into barrel. 3. Make sure the hydrometer float rides freely in electrolyte. Clean inside of barrel with soap and water if float persistently sticks to side of barrel. Clean and dry before use. 4. Make certain readings on float are at eye level. 5. Adjust reading according to temperature of electrolyte. Add .004 for each 10 o (12 oC) above 80°F (26°C). or subtract .004 for each 10o (12oC) below 80°F (26°C). If there is a difference of more than .05 volts between the highest and lowest cells, replace the battery. If there is less than .05 volts between the highest and lowest cells, charge the battery per the chart. If battery is above 9.6 volts the battery is o.k. If battery reads less than 9.6 volts after charge, the battery is ready to be replaced. Use caution in reconnecting the battery cables to the battery. An accidental reversal of polarity can cause damage to the regulator-rectifier.

Battery Condition

Specific Gravity

Discharged

1.110 to 1.130

No useful charge

1.140 to 1.160

25%

1.170 to 1.190

50%

1.200 to 1.220

75%

1.230 to 1.250

100%

1.260 to 1.280

55

SECTION 4. ELECTRICAL CONTROL PANELS IGNITION CUT-OFF TOGGLE SWITCH

AMMETER

BROWN

on ON-OFF SWITCH off

BROWN HEAVY DUTY PUSH BUTTON STARTER SWITCH

ELECTRICAL CONTROL PANEL SERVICE PART NO. 730155. The test procedures explained below will deal only with the control panel. Before attempting to locate an apparent defect in the control panel switches or ammeter, insure all connections between control panel, starter and battery are secure and free from corrosion and wire or insulation breaks. Battery should be fully charged or be at a minimum of 75% charge. Engine ignition spark should be checked for an intense spark. Remove side plates from control panel. Remove engine alternator connector plug from panel connector. Use a volt-ohm-millimeter or battery powered test light for the following tests. CAUTION - Remove (+) lead from battery before attempting any of the following tests.

BATTERY POWERED CONTINUITY TESTER REMOVE POSITIVE (+) LEAD WIRE FROM BATTERY

ON-OFF SWITCH - DC RELAY CIRCUIT. Remove both brown wires from switch terminal. Attach test leads to switch terminal. Place switch to the “ON” position. Continuity (test light should light) should exist. Leave test leads attached and move switch to the “OFF” position. Continuity should not exist (test light should not light). If switch fails either of these tests, switch must be replaced.

BROWN REMOVE STARTER MOTOR WIRE

GREEN STARTER SWITCH ON-OFF SWITCH REMOVE POSITIVE (B+) WIRE FROM BATTERY

GREEN

BATTERY POWERED CONTINUITY TESTER REMOVE POSITIVE (+) LEAD WIRE FROM BATTERY

ON-OFF SWITCH IGNITION GROUND CIRCUIT. Remove both the green wires from switch terminals. Attach test leads of tester (Battery type test light or ohmmeter) to switch terminals. Move toggle switch to the “ON” position. No continuity (light should not light) should exist. Leave test leads attached to switch and move switch to “OFF” position. Continuity should exist (light should light). If switch fails to either test, switch must be replaced. 56

BATTERY POWERED CONTINUITY TESTER

STARTER SWITCH. Remove wires from starter switch. Place test leads on to switch terminals. No continuity should exist (Test light should not light). Leave test leads attached depress starter button. Continuity should exist (Test light should light). If starter switch fails either of these tests, replace switch. AMMETER. CAUTION The ammeter will not show a charge if the battery is at full charge. The rate of charge will depend on the amount of charge in the battery. The lower the charge in the battery, the higher the reading on the ammeter. If ammeter does not show a charge or discharge, start and stop engine (use electric starter) several times to lower charge of the battery. Observe ammeter and if there is no deflection, proceed with the following test.

To test ammeter remove right side panel. Remove brown wire from “On/Off” switch. Use a volt/ohm/ millimeter. Attach one test lead to the terminal the brown wire was removed from, attach other test lead to positive terminal of start switches. Set tester to the ampere scale and start engine. Set throttle control at full throttle and observe meter. If meter registers a charge, system is okay and meter on panel is inoperative. This test can also be made using a good ammeter. Attach a wire to each terminal of the ammeter and hookup as described above. No reading on either meter would indicate a problem with the regulatorrectifier and/or alternator.

BROWN

STARTER SWITCH

ON-OFF TOGGLE SWITCH

ELECTRICAL CONTROL PANEL SERVICE PART NO. 730198. The following test procedures will be limited to the control panel. Test procedures for electrical components external to this control panel will be found in their respective areas. Before attempting to locate an apparent defect in the control panel switches insure all connections between control panel, starter and battery are secure and free from corrosion and wire or insulation breaks. Battery should be fully charged or be at a minimum of 75% charge. Engine ignition spark should be checked for an intense spark. DISCONNECT FROM BATTERY STARTER SWITCH

ON-OFF TOGGLE SWITCH

(GREEN LEAD)

AMMETER

CONNECTOR

FUSE GROUND

(GREEN LEAD)

ALLIGATOR CLIPS BATTERY POWERED CONTINUITY TESTER NO. 16 WIRE

CAUTION - Remove the control panel from the engine bracket then remove (+) lead from battery before attempting any of the following tests. ON-OFF TOGGLE SWITCH-IGNITION GROUND CIRCUIT. Note: One of several continuity testers may be used. For the following tests a battery powered continuity tester is used.

ALTERNATOR CONNECTOR IGNITION GROUND

DISCONNECT FROM STARTER

BROWN

REGULATOR RECTIFIER SWITCH

AMP

A. Test for switch continuity of magneto cutout circuit.

ON POSITION FROM BATTERY

When disconnecting spade connectors from terminals use care not to damage wire connections or switch terminals. The use of a pair of needlenosed pliers is recommended.

NO. 6 WIRE

1. Disconnect the two green leads by pulling spade connectors off of terminals. 2. Place continuity tester probes on each switch terminal. 57

3. With the toggle switch in the “off” position, the test light will light. 4. With the toggle switch in the “on” position, the test light will not light. 5. Position the spade connectors to the original positions. DISCONNECT FROM BATTERY ON-OFF TOGGLE SWITCH

STARTER SWITCH CONTINUITY TEST. Remove wires from starter switch. Place test leads on to switch terminals. No continuity should exist (Test light should not light). Leave test leads attached; depress starter button. Continuity should exist (Test light should light). If starter switch fails either of these tests, replace switch.

STARTER SWITCH

PUSH IN

SPRING

(RED LEAD) FUSE GROUND TURN CCW

REMOVE

(RED LEAD)

CONNECTOR DISCONNECT FROM STARTER BATTERY POWERED CONTINUITY TESTER

FUSE (30 AMP) (3 AG)

2. Disconnect the other spade connector (red wire) from the switch terminal.

FUSE. To remove the fuse, push the cap in to compress spring at base of fuse holder and with same motion turn the cap counterclockwise (ccw) and pull cap away from holder. Fuse can now be removed from holder. Inspect condition of fuse. If in doubt, perform continuity test on fuse and/or connections in fuse holder. To reinstall, reverse disassembly procedure.

3. Place continuity tester probes on each switch terminal.

If fuse is defective, replace with a 12 volt/30 amp. size. (3 AG)

B. Test for switch continuity of D.C. circuit. 1. Disconnect the spade connector (red wire) from the switch terminal.

4. With the toggle switch in the “on” position the test light will light.

STARTER SWITCH ON (POSITION)

5. With the toggle switch in the “off” position the test light will not light. 6. Position the spade connectors to the original positions. DISCONNECT FROM BATTERY ON-OFF TOGGLE SWITCH

RED

TO BATTERY NO. 14 WIRE (RED) NO. 6 WIRE

GREEN OFF (POSITION)

FUSE

STARTER SWITCH

FUSE GROUND

NO. 12 WIRE (RED)

NO. 6 WIRE TO STARTER

NO. 16 WIRE (GREEN)

CONNECTOR

BATTERY POWERED CONTINUITY TESTER REMOVE WIRES FROM STARTER SWITCH TERMINALS

If either of the tests do not give the correct results, replace the switch. 58

WIRING DIAGRAM. The wiring diagram is shown to show the correct placement of electrical connections, color code and wire gauge. The wire to the battery is supplied by the O.E.M.

TROUBLESHOOTING FOR ELECTRICAL CONTROL PANEL, SERVICE PART NO. 730155. TROUBLE Electric Starter Does Not Crank Engine

PROBABLE CAUSE Check to determine if crankshaft turns freely; if not, check for binding belts, pulleys, clutches, etc.

Relieve load on crankshaft. Disengage associated equipment clutches, belts or pulleys.

Check battery connections for corrosion and/or breaks.

Correct problem.

Weak or bad battery.

Replace or charge battery if less than 3/4 charged.

Push button starter switch.

Replace if inoperative. See Service Instruction on preceding pages.

Electric starter.

See troubleshooting chart.

Panel wiring.

Correct problem.

Starter Cranks Engine But Engine Toggle switch. Does Not Start Insure spade connectors are secured to appropriate switch terminals. Ammeter Does Not Show A Charge Weak or bad battery. (If battery is fully charged, ammeter will not show a charge)

Ammeter Shows A Discharge.

REMEDY

If inoperative, replace. See Service Instructions on preceding pages. Correct. See Service Instructions on preceding pages. See “Engine Fails to Start” Charge or replace.

Faulty wiring and/or connections.

Correct or replace.

Shorted or open alternator.

Replace.

Regulator-Rectifier.

Replace.

Ammeter.

Replace if inoperable. See Service Instruction on preceding pages.

Broken wiring and/or insulation.

Correct problem.

Toggle switch.

Check and replace if inoperable. See Service Instructions on preceding pages.

59

TROUBLESHOOTING FOR ELECTRICAL CONTROL PANEL, SERVICE PART NO. 730198. TROUBLE

PROBABLE CAUSE

Electric Starter Does Not Crank Engine.

Check to determine if crankshaft Relieve load on crankshaft. turns freely; if not, check for Disengage associated equipment binding belts, pulleys, clutches, etc. clutches, belts or pulleys.

Starter Cranks Engine But Engine Does Not Start.

60

REMEDY

Check battery connections for corrosion and/or breaks.

Correct problem.

Weak or bad battery.

Replace or charge battery if less than 3/4 charged.

Push button starter switch.

Replace if inoperative. See Service Instruction on preceding pages.

Electric starter.

See troubleshooting chart.

Panel wiring.

Correct problem.

Toggle Switch

If inoperative, replace. See Service Instruction on preceding pages.

Insure spade connectors are secured to appropriate switch terminals.

Correct problem.

CHAPTER 9. TROUBLESHOOTING TROUBLESHOOTING Below is a list of common problems and remedies. Follow a uniform procedure to locate and eliminate the causes. Cause

Remedy

A. ENGINE FAILS TO START OR STARTS WITH DIFFICULTY No fuel in tank.

Fill tank with clean, fresh fuel.

Shut-off valve closed.

Open valve

Obstructed fuel line.

Clean fuel screen and line. If necessary, remove and clean carburetor.

Tank cap vent obstructed.

Open vent in fuel tank cap.

Water in fuel.

Drain tank. Clean carburetor and fuel lines. Dry spark plug electrodes. Fill tank with clean, fresh fuel.

Engine over-choked.

Close fuel shut-off and pull starter until engine starts. Reopen fuel shut-off for normal fuel flow.

Improper carburetor adjustment.

Adjust carburetor.

Loose or defective magneto wiring.

Check magneto wiring for shorts or grounds; repair if necessary.

Faulty ignition unit.

Check ignition unit. Solid State. Check points, timing on standard ignition units.

Spark plug fouled.

Clean and regap spark plug.

Spark plug porcelain cracked.

Replace spark plug.

Poor compression.

Check compression.

No spark at plug.

Disconnect ignition cut-off wire at the engine. Crank engine. If spark at spark plug, ignition switch, safety switch or interlock switch is inoperative. If no spark, check magneto. Check wires for poor connections, cuts, or breaks.

Electric starter does not crank engine.

See 12 volt starter trouble shooting chart page.

B. ENGINE KNOCKS Carbon in combustion chamber.

Remove cylinder head and clean carbon from head and piston.

Loose or worn connecting rod.

Replace connecting rod.

Loose flywheel.

Check flywheel key and keyway; replace parts if necessary. Tighten flywheel nut to proper torque (See Table of Specifications).

Worn cylinder.

Recondition cylinder or replace.

Improper Magneto Timing.

Time ignition.

Improperly set ignition unit.

Check ignition unit.

Excessive main bearing end play.

Readjust to correct crankshaft end play.

61

C. ENGINE MISSES UNDER LOAD Cause

Remedy

Spark plug fouled.

Clean and regap spark plug.

Spark plug porcelain cracked.

Replace spark plug.

Improper spark plug gap.

Regap spark plug.

Pitted magneto breaker points.

Clean and dress breaker points. Replace badly pitted breaker points.

Magneto breaker arm sluggish.

Clean and lubricate breaker point rod and arm. Check for spring tension.

Faulty condenser.

Check condenser on a tester; replace if defective.

Improper carburetor adjustment.

Adjust carburetor.

Improper valve clearance.

Adjust valve clearance.

Weak valve spring.

Replace valve spring.

D. ENGINE LACKS POWER Choke partially closed.

Open choke.

Improper carburetor adjustment.

Adjust carburetor.

Magneto improperly timed.

Time engine.

Loss of compression.

Check compression.

Lack of lubrication.

Fill crankcase to the proper level.

Air cleaner restricted.

Clean or replace air cleaner.

Valves leaking.

Grind valves.

Valve timing inaccurate.

Check timing marks on camshaft and crankshaft gear.

Carburetor dirty or damaged.

Clean, repair carburetor. See Carburetor Chapter 2.

Ignition system malfunction.

Check and repair system.

E. ENGINE OVERHEATS Engine improperly timed.

Time engine.

Carburetor improperly adjusted (lean).

Adjust carburetor.

Air flow obstructed.

Remove any obstructions from air passages in shrouds.

Excessive load on engine.

Check operation of associated equipment. Reduce excessive load.

Carbon in combustion chamber.

Remove cylinder head and clean carbon from head and piston.

Lack of lubrication.

Fill crankcase to proper level.

F. ENGINE SURGES OR RUNS UNEVENLY. Fuel tank cap vent hole clogged.

Open vent hole.

Governor parts sticking or binding.

Clean, and if necessary repair governor parts.

Carburetor throttle linkage or throttle shaft and/or butterfly binding or sticking.

Clean, lubricate, or adjust linkage and deburr throttle shaft or butterfly.

62

Cause

Remedy

Governor not properly adjusted.

Adjust governor.

Carburetor not properly adjusted.

Adjust carburetor.

Intermittent spark at spark plug.

Disconnect ignition cut-off wire at the engine. Crank engine. If spark, check ignition switch, safety switch and interlock switch. If no spark, check magneto. Check wires for poor connections cuts or breaks.

G. ENGINE VIBRATES EXCESSIVELY Engine not securely mounted.

Tighten loose mounting bolts.

Bent crankshaft.

Replace crankshaft.

Associated equipment out of balance.

Check associated equipment.

Counterbalance counterweights not properly aligned. Check. H. ENGINE USED EXCESSIVE AMOUNT OF OIL. Engine speed too fast.

Using tachometer adjust engine RPM to specification.

Oil level too high.

Check level turn dipstick cap tightly into receptacle for accurate level reading.

Oil filler cap loose or gasket damaged causing spillage out of breather.

Replace ring gasket under cap and tighten cap securely.

Breather mechanism damaged or dirty causing leakage.

Replace breather assembly.

Gaskets or “O” rings damaged or gasket or “O” ring surfaces nicked causing oil to leak out.

Install new gaskets or “O” rings.

Valve guides worn.

Ream valve guide oversize and install 1/32'’ (.787 mm) oversize valve.

Cylinder wall worn or glazed allowing oil to pass rings into combustion chamber.

Deglaze cylinder as necessary.

Piston rings and grooves worn excessively.

Reinstall new rings and check land clearance and correct as necessary.

Piston fit too loose.

Measure and replace as necessary.

Piston oil control ring return holes clogged.

Remove oil control ring and clean return holes.

Oil passages obstructed.

Clean out all oil passages.

I. OIL SEAL LEAKS Seal hardened or worn.

Replace seal.

Crankshaft seal contact surface is slightly scratched causing seal to wear excessively.

Crankshaft seal rubbing surface must be smoothed before installing new seal. Use a fine crocus cloth. Care must be taken when removing seals.

Crankshaft bearing under seal is worn excessively Check crankshaft bearings for wear and replace if causing crankshaft to move. necessary. Seal outside seat (oil seal bore) in cylinder or side cover is damaged allowing oil to seep around outer edge of seal.

Visually check seal receptacle (oil seal bore) for damage. Replace P.T.O. cylinder cover or small cylinder cover on the magneto end, if necessary.

New seal installed without correct seal driver and not seating squarely in cavity.

Replace with new seal using proper tools and methods. 63

Cause

Remedy

New seal damaged upon installation.

Use proper seal protector tools and methods for installing another new seal.

Bent crankshaft causing seal to leak.

Check crankshaft for straightness and replace if necessary. (Never straighten a bent crankshaft)

Oil seal driven too far into cavity.

Remove seal and replace with new seal using the correct driver tool and procedures.

J. BREATHER PASSING OIL Engine speed too fast.

Use tachometer to adjust correct RPM.

Loose oil fill cap or gasket damaged or missing.

Install new ring gasket under cap and tighten securely.

Oil level too high.

Check oil level Turn dipstick cap tightly into receptacle for accurate level reading. DO NOT fill above full mark.

Breather mechanism damaged.

Replace.

Breather mechanism dirty.

Clean thoroughly in solvent.

Piston ring end gaps aligned.

Rotate end gaps so as to be staggered 90° apart.

Drain hole in breather box clogged.

Clean hole with wire to allow oil to return to crankcase.

Breather mechanism loose or gaskets leaking.

Install new gaskets and tighten securely.

Damaged or worn oil seals on end of crankshaft.

Replace seals.

Rings not seated properly.

Check for worn or out of round cylinder. Replace rings. Break in new rings with engine working under a varying load. Rings must be seated under high compression or in other words under varied load conditions.

Breather assembly not assembled correctly on engine. Refer to breather section. Cylinder cover gasket leaking.

64

Replace cover gaskets.

K. TROUBLE SHOOTING CARBURETION POINTS TO CHECK FOR CARBURETOR MALFUNCTION Trouble

Correction

Carburetor out of adjustment .....................................

4-12-13-14-15-17-22

Engine will not start ....................................................

1-2-3-4-5-6-7-9-12-13

Engine will not accelerate ..........................................

3-4-12-13-14-26

Engine hunts (at idle or high speed) .........................

4-5-9-10-11-12-13-14-22-23-26

Engine will not idle......................................................

5-9-10-12-14-15-16-22-23-24-26

Engine lacks power at high speed ............................

3-4-7-9-12-13-22-23-26

Carburetor floods ........................................................

5-8-19-23-24

Carburetor leaks .........................................................

7-8-11-20-25-26

Engine overspeeds .....................................................

9-10-12-16-17-20-22

Idle speed is excessive ..............................................

9-10-15-16-17-20-22

Choke does not open fully .........................................

9-10-17

Engine starves for fuel at high speed (leans out) ..

1-2-4-5-7-12-17-19-21-23

Carburetor runs rich with main adjustment needle shut off

8-12-19-20-21-23

Performance unsatisfactory after being serviced ..

1thru 14 and 17 thru 23

1. Open fuel shut-off valve at fuel tank, fill tank with fuel.

14. Adjust idle mixture adjustment screw. Check to see that it is the correct screw.

2. Examine and clean fuel line and filter (where applicable).

15. Adjust idle speed screw.

3. Check ignition, spark plug and compression.

16. Check position of choke and throttle plates.

4. Clean air cleaner, service as required.

17. Adjust control cable or linkage to assure full choke and carburetor control.

5. Dirt or restriction in fuel system, clean tank and fuel strainers, check for kinks or sharp bends.

18. Clean carburetor after removing all non-metallic parts that are serviceable. Trace all passages.

6. Check for stale fuel or water in fuel, fill with fresh fuel.

19. Check inlet needle and seat condition and proper installation.

7. Examine fuel line and pick-up for sealing at fittings.

20. Check sealing of welch plugs, cups, plugs and gaskets.

8. Check and clean atmospheric vent holes. 9. Examine throttle and choke shafts for binding or excessive play, remove all dirt or paint, replace shaft. 10. Examine throttle and choke return springs for operation.

21. Check fuel pump operation of pulse pump, clean the pulse line after removing it from the pump and engine fittings. 22. Adjust governor linkage. 23. Adjust float setting.

11. Examine idle and main mixture adjustment screws and “O” rings for cracks or damage.

24. Check float shaft for wear and float for leaks or dents.

12. Adjust main mixture adjustment screw. Check to see that it is the correct screw.

25. Check seal for fuel drain or bowl gasket.

13. Examine main nozzle and replace with service nozzle.

26. Is carburetor operating at excessive angle, 31° or more ? 65

CHAPTER 10. 8 H.P. & LARGER ENGINE AND TORQUE SPECIFICATIONS ALSO VALVE-IN-HEAD SPECIFICATIONS AND TORQUES SECTION 1. CROSS REFERENCE LIST FOR TABLE OF SPECIFICATIONS Craftsman Engine Model

See Model

Craftsman Engine Model

143.558012 143.558022 143.558032 143.558052 143.559012 143.559022 143.559032 143.559042 143.562012 143.562022 143.562032 143.568032 143.569022 143.569032 143.569042 143.569052 143.569082 143.572012 143.572022 143.572032 143.572042 143.572052 143.572062 143.572092 143.572102 143.578012 143.578022 143.578052 143.578062 143.578072 143.579012 143.579022 143.579032 143.579042 143.579052 143.579062 143.579072 143.579082 143.579092 143.579102 143.579112 143.579132 143.582012 143.582022 143.582032 143.582042 143.582052 143.582062 143.582072 143.582082 143.582092 143.582102 143.582112 143.582122 143.582132 143.582142 143.582172 143.588012

HH80 HH80 HH80 HH80 HH100 HH100 HH100 HH100 HH120 HH120 HH1200 HH80 HH100 HH100 HH100 HH100 HH100 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH80 HH80 HH80 HH80 HH80 HH100 HH100 HH100 HH100 HH100 HH100 HH100 HH100 HH100 HH100 HH100 HH100 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH80

143.588032 143.589012 143.589022 143.589032 143.589042 143.589052 143.589072 143.592012 143.592022 143.592032 143.592052 143.592062 143.592072 143.592082 143.598012 143.599012 143.599022 143.599042 143.599052 143.599062 143.602012 143.602022 143.602032 143.602052 143.602062 143.602072 143.602082 143.602092 143.602102 143.602112 143.602122 143.608012 143.608022 143.608032 143.609022 143.609032 143.609042 143.609052 143.609072 143.612012 143.612022 143.619012 143.622012 143.622022 143.622032 143.622042 143.622052 143.622062 143.622072 143.622082 143.622092 143.622102 143.628012 143.628022 143.629012 143.629022 143.629032 143.629042

66

See Model

Craftsman Engine Model

See Model

HH80 HH100 HH100 HH100 HH100 HH100 HH100 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH80 HH100 HH100 HH100 HH100 HH100 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH80 HH80 HH80 HH100 HH100 HH100 HH100 HH100 HH120 HH120 HH100 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH80 HH80 HH100 HH100 HH100 HH100

143.629052 143.629062

HH100 HH100

143.629072

HH100

143.632022

HH120

143.632032

HH120

143.632042

HH120

143.639012

HH100

143.642012

HH120

143.642022 143.642032 143.642042 143.649012 143.649022 143.652012 143.652022 143.652032 143.652042 143.652052 143.652062 143.652072 143.659012 143.659022 143.659032 143.662012 143.669012 143.672012 143.672022 143.672032 143.672042 143.672052 143.672062 143.672072 143.676082 143.679012 143.679022 143.679032 143.712012 143.712022 143.712032 143.712042 143.760012 143.780012

HH120 HH120 HH120 HH100 HH100 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH100 HH100 HH100 HH120 HH100 HH120 HH120 HH120 HH120 HH120 HH120 HH120 HH100 HH100 HH100 HH100 HH120 HH120 HH120 HH120 HH120 HH120

Craftsman Engine Model

See Model

Model

HH80

HH100

U.S.

Metric

Displacement

23.7

384.4cc

Stroke

2-3/4'’

Bore

Timing Dimension

69.85mm

U.S.

HH120

Metric

U.S.

Metric

23.7

284.4cc

27.66

453.4 cc

2-3/4'’

69.85mm

2-7/8'’

73.025mm

3.3120

84.125

3.3120

84.125

3.500

88.900mm

3.3130

84.150

3.3130

84.150

3.501

88.925mm

TDC-Start .095 Run

TDC-Start 2.41

.095 Run

TDC-Start 2.41

.095 Run

2.41mm

Point Gap

.020

.508

.020

.508

.020

.508

Spark Plug Gap

.028 .033

.711 .838

.028 .033

.711 .838

.028 .033

.711mm .838mm

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254mm .508mm

Valve Clearance

Intake Exhaust

Valve Seat Angle Valve Seat Width

46°

46°

46°

.042

.042

.042

1.067

.042

1.067mm

.052

.052

.052

1.321

.052

1.321mm

Valve Face Angle

45°

Valve Face Width

.089 .099

2.261 2.515

.089 .099

2.261 2.515

.089 .099

2.261 2.515

Valve Lip Width

.06

1.524

.06

1.524

.06

1.524

1.885

47.879

1.885

47.879

1.885

47.879

Valve Spring Free Length Valve Guides STD Diameter

Valve Guides Over-Size Dimensions

Dia. Crankshaft Conn. Rod Journal

45°

Piston Diameter

45°

45°

.312

7.925

.312

7.925

.312

7.925

7.950

.313

7.950

.313

7.950

.343

8.712

.343

8.712

.343

8.712

.344

8.738

.344

8.738

.344

8.738

1.3750

34.925

1.3750

34.925

1.3750

34.925

1.3755

34.938

1.3755

34.938

1.3755

34.938

1.3765

Crankshaft End Play

45°

.313

Maximum Conn. Rod Dia.Crank Bearing Maximum

Shaft Seat Dia. for Roller Bearings

45°

Maximum 34.963

1.3765

Maximum 34.963

1.3765

34.963

1.1865

30.137

1.1865

30.137

1.1865

30.137

1.1870

30.150

1.1870

30.150

1.1870

30.150

None 3.3080 3.3100

None 84.023 84.074

3.3080 3.3100

None 84.023 84.074

3.4950 3.4970

88.773 88.824

NOTE: All dimensions are in inches and millimeters unless noted.

67

Model

HH80

HH100

HH120

U.S.

Metric

U.S.

Piston Pin Diameter

.6873 .6875

17.457 17.463

.6873 .6875

17.457 17.463

.6873 .6875

17.457 17.463

Width Comp. Ring Groove

.0950 .0960

2.413 2.438

.0950 .0960

2.413 2.438

.0950 .0960

2.413 2.438

Width Oil Ring Groove

.1880 .1900

4.775 4.826

.1880 .1900

4.775 4.826

.1880 .1890

4.775 4.826

Side Clearance Ring Groove

.0020 .0035

.051 .889

.0020 .0035

.051 .889

.0020 .0035

.051 .889

Ring End Gap

.007 .020

.178 .508

.007 .020

.178 .508

.007 .020

.178 .508

Top Piston Land Clearance

.0305 .0335

.775 .851

.030 .035

.762 .889

.031 .036

.787 .914

Piston Skirt Clearance

.002 .005

.051 .127

.002 .005

.051 .127

.003 .006

.076 .127

Camshaft Bearing Diameter

.6235 .6240

15.837 15.850

.6235 .6240

15.837 15.850

.6235 .6240

15.837 15.850

Cam Lobe Diameter Nose to Heel

1.3045 1.3085

33.134 33.326

1.3045 1.3085

33.134 33.236

1.3045 1.3085

33.134 33.236

Magneto Air Gap

.006 .010

.152 .254

.006 .010

.152 .254

.006 .010

.152 .254

Model

Metric

VH80

U.S.

Metric

VH100

U.S.

Metric

Displacement

23.7

388.4 cc

23.7

388.4 cc

Stroke

2-3/4'’

69.85

2-3/4'’

69.85

Bore

3.3120 3.3130

84.125 84.150

3.3120 3.3130

84.125 84.150

Timing Dimension

Solid State

Solid State

Point Gap

Solid State

Solid State

Spark Plug Gap

.035

.889

.035

.889

.010 .020

.254 .508

.010 .020

.254 .508

Valve Seat Angle

46°

46°

46°

46°

Valve Seat Width

.042 .052

1.067 1.321

.042 .052

1.067 1.321

Valve Clearance

68

Intake Exhaust

U.S.

Metric

Model

VH80

VH100

U.S.

Metric

U.S.

Metric

Valve Face Angle

45°

45°

45o

45o

Valve Face Width

.089 .099

2.261 2.515

.089 .099

2.261 2.515

Valve Lip Width

.06

1.524

.06

1.524

Valve Spring Free Length

1.885

47.879

1.885

47.879

Valve Guides STD Diameter

.312 .313

7.925 7.950

.312 .313

7.925 7.950

Valve Guides Over-Size Dimensions

.344 .345

8.738 8.763

.344 .345

8.738 8.763

Diameter Crankshaft Conn. Rod Journal

1.3750 1.3755

34.925 34.938

1.3750 1.3755

34.925 34.938

Maximum Conn. Rod Dia. Crank Bearing

1.3761

44.097

1.3761

44.097

Shaft Seat Dia. for Roller Bearings

1.1865 1.1870

30.137 30.150

1.1865 1.1870

30.137 30.150

Crankshaft End Play

None

Piston Diameter

3.308 3.310

84.023 84.074

3.308 3.310

84.023 84.074

Piston Pin Diameter

.6873 .6875

17.457 17.463

.6873 .6875

17.457 17.463

Width Comp. Ring Groove

.0950 .0960

2.41 2.438

.0950 .0960

2.41 2.438

Width Oil Ring Groove

.1800 .1900

4.572 4.826

.1800 .1900

4.572 4.826

Side Clearance Ring Groove

.0025 .0030

.635 .076

.0025 .0030

.635 .076

Ring End Gap

.010 .020

.254 .508

.010 .020

.254 .508

Top Piston Land Clearance

.0305 .0335

.775 .851

.0305 .0335

.775 .851

Piston Skirt Clearance

.003

.076

.003

.076

Camshaft Bearing Diameter

.6235 .6240

15.837 15.850

.6235 .6240

15.837 15.850

Cam Lobe Diameter Nose to Heel

1.3045 1.3085

33.134 33.236

1.3045 1.3085

33.134 33.236

Magneto Air Gap

.006 .010

.152 .254

.006 .010 Solid State

.152 .254

None

NOTE: All dimensions are in inches and millimeters unless noted. 69

SECTION 2. TORQUE SPECIFICATIONS 8 H.P. & LARGER ENGINES (EXCEPT VALVE-IN-HEAD) INCH POUNDS

NEWTON METER

Cylinder Head Bolts

180 - 240

20.3 - 27.1

Connecting Rod Lock Nuts

86 - 110

9.7 - 12.4

Mounting Flange or Cylinder Cover

100 - 130

11.3 - 14.7

Flywheel Nut

600 - 660

67.8 - 74.6

Spark Plug

220 - 280

24.9 - 31.6

Carburetor to Cylinder

72 - 96

8.1 - 10.9

Air Cleaner to Elbow

15 - 25

1.7 - 2.8

Air Cleaner Bracket to Carburetor

15 - 25

1.7 - 2.8

Tank Bracket to Housing

35 - 50

4.0 - 5.7

Tank Bracket to Cylinder (5/16'’ Lower)

150 - 200

17 - 22.6

Tank Bracket to Head Bolt

150 - 200

17 - 22.6

Starter-Top Mount Recoil

40 - 60

4.5 - 6.8

Belt Guard to Blower Housing

25 - 35

2.8 - 4.0

Flywheel Screen & Pulley

72 - 96

8.1 - 10.9

Stationary Point Screw

15 - 20

1.7 - 2.3

Blower Housing Baffle to Cylinder

72 - 96

8.1 - 10.9

Blower Housing to Baffle or Cylinder

48 - 72

5.4 - 8.1

Breaker Point Cover

15 - 25

1.7 - 2.8

Magneto Stator Mounting

72 - 96

8.1 - 10.9

Breather to Cylinder

20 - 25

2.3 - 2.8

Oil Drain Plug 3/8 18

80 - 100

9.0 - 11.3

Blower Housing Extension to Cylinder

72 - 96

8.1 - 10.9

Stub Shaft Bolts to Flywheel

100 - 125

11.3 - 14.1

Motor Generator all Mounting Bolts

65 - 100

7.4 - 11.3

NOTE: Divide by 12 for foot pounds. 70

SECTION 3. VALVE-IN-HEAD ENGINE SPECIFICATIONS Description

Model OH120 Model OH140 U.S. Metric U.S. Metric

See Note

Model OH150 Model OH160 U.S. Metric U.S. Metric

See Note

Model OH180 U.S. Metric

See Note

Displacement

21.1

346 cc

23.7

388 cc

27.66

453 cc

27.66

453 cc

30.0

492 cc

Stroke

2.75

69.80

2.75

69.80

2.875

69.80

2.875

69.80

2.875

69.80

Bore

3.125 3.126

79.375 79.400

3.312 3.313

84.125 84.150

3.500 3.501

88.900 88.925

3.500 3.501

88.900 88.925

3.625 3.626

92.075 92.100

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Valve Clearance Intake Exhaust

.005 .010

.0127 .254

.005 .010

.0127 .254

.005 .010

.0127 .254

.005 .010

.0127 .254

.005 .010

.0127 .254

Valve Seat Angle

46°

Valve Seat Width

.042 .052

1.067 1.321

.042 .052

1.067 1.321

.042 .052

1.067 1.321

.042 .052

1.067 1.321

.042 .052

1.067 1.321

Valve Face Angle

45° +

45o

45° +

45o

45° +

45o

45° +

45o

45° +

45o

Valve Face Width

.094

2.388

.133

3.378

.133

3.378

.133

3.378

.133

3.378

Valve Lip Width

.06

1.524

.06

1.524

.06

1.524

.06

1.524

.06

1.524

Valve Spring Free Length

1.915

48.641

1.980

50.292

1.980

50.292

1.980

50.292

1.980

50.292

Valve Guides STD Diameter

.312 .313

7.925 7.950

.312 .313

7.925 7.950

.312 .313

7.925 7.950

.312 .313

7.925 7.950

.312 .313

7.925 7.950

Dia. Crankshaft Conn. Rod Journal

1.3750 1.3755

34.925 34.938

1.3750 1.3755

34.925 34.938

1.3750 1.3755

34.925 34.938

1.3750 1.3755

34.925 34.938

1.3750 1.3755

34.925 34.938

Maximum Conn. Rod Dia.

1.3765

34.963

1.3765

34.963

1.3765

34.963

1.3765

34.963

1.3765

34.963

Shaft Seat Dia. for Roller Bearings

1.1865 1.1870

30.137 30.150

1.1865 1.1870

30.137 30.150

1.1865 1.1870

30.137 30.150

1.1865 1.1870

30.137 30.150

1.1865 30.137 1.1870 30.150

Crankshaft End Play

*None .001 .025 .007 .178 Preload

*None .001 .025 .007 .178 Preload

*None .001 .025 .007 .178 Preload

*None .001 .007 Preload

.025 .178

*None .001 .025 .007 .178 Preload

Piston Skirt Diameter

3.121 3.123

79.273 79.324

3.3080 3.3100

84.023 84.074

3.4950 3.4970

88.773 88.824

3.4950 3.4970

88.773 88.824

3.620 3.622

Piston Pin Diameter

.6876 .6880

17.465 17.475

.6876 .6880

17.465 17.475

.6876 .6880

17.465 17.475

.6876 .6880

17.465 17.475

.7810 .7812

Width Comp. Ring Groove

.0950 .0960

2.413 2.438

.0950 .0960

2.413 2.438

.0950 .0960

2.413 2.438

.0950 .0960

2.413 2.438

.0955 .0965

Width Oil Ring Groove

.1880 .1900

4.775 4.826

.1880 .1900

4.775 4.826

.1880 .1890

4.775 4.826

.1880 .1890

4.775 4.826

.1880 .1895

46°

46°

46°

46°

Crank Bearing

Note: First Model Year was designated as an HH140, 150, 160.

91.948 91.999

4.775 4.826

71

Description

Model OH120 Model OH140 Model OH150 Model OH160 Model OH180 U.S. Metric U.S. Metric U.S. Metric U.S. Metric U.S. Metric

Side Clearance Ring Groove Compression

.0015 .038 .0035 .089

.0015 .0035

.038 .089

.0015 .0035

.038 .089

.0015 .0035

.038 .089

.0015 .0035

.038 .089

Ring End Gap

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

Top Piston Land Clearance

.031 .034

.787 .864

.030 .035

.762 .889

.031 .036

.787 .864

.031 .036

.787 .864

.031 .036

.787 .864

Camshaft Bearing Diameter

.6235 15.837 .6240 15.850

.6235 .6240

15.837 15.850

.6235 .6240

15.837 .6235 15.850 .6240

Cam Lobe Diameter Nose to Heel

1.3117 33.317 1.3167 33.444

1.3117 33.317 1.3167 33.444

CROSS REFERENCE LIST Craftsman Engine Model See Model 143.626272 143.630012 143.630022 143.640012 143.640022 143.640032 143.640042 143.640052 143.650012 143.650022 143.650032 143.660012 143.660022 143.670012 143.670032 143.670042

OH160 OH160 OH160 OH160 OH160 OH160 OH160 OH160 OH160 OH160 OH160 OH160 OH160 OH140 OH160 OH140

15.837 .6235 15.850 .6240

15.837 15.850

1.3117 33.317 1.3117 33.317 1.3117 33.317 1.3167 33.444 1.3167 33.444 1.3167 33.444

CROSS REFERENCE LIST Craftsman Engine Model See Model 143.670052 143.670062 143.670072 143.670082 143.670092 143.680012 143.680022 143.680032 143.700012 143.710012 143.710022 143.730012 143.730022 143.740012 143.740022 143.770022

OH160 OH160 OH160 OH140 OH140 OH140 OH140 OH160 OH180 OH160 OH140 OH160 OH140 OH140 OH160 OH180

“Torque specifications listed on this page should not be confused with the torque value observed on engines which have been run. Torque relaxation occurs on all engines from thermal expansion and contraction. The torque specifications take relaxation into account so a sufficient clamping force exists after an engine has been run.”

72

SECTION 4. TORQUE SPECIFICATIONS VALVE-IN-HEAD TORQUE SPECIFICATIONS INCH

Nm

180 - 240

20.3 - 27.1

86 - 110

9.7 - 12.4

Mounting Flange Cylinder Cover Screw

100 - 130

11.3 - 14.7

Cylinder Cover Flywheel End

120 - 160

13.6 - 18.1

Flywheel Nut

600 - 660

67.8 - 74.6

P.T.O. Shaft to Flywheel

100 - 125

11.3 - 14.1

Spark Plug

220 - 280

24.9 - 31.6

Intake Pipe to Cylinder

72 - 96

8.1 - 10.9

Carburetor to Intake Pipe

48 - 72

5.4 - 8.1

Air Cleaner Elbow to Carburetor

25 - 35

2.8 - 4.0

Air Cleaner Bracket to Elbow

15 - 25

1.7 - 2.8

Air Cleaner Bracket to Carburetor

15 - 25

1.7 - 2.8

Tank Bracket to Cylinder (5/16'’ Lower)

150 - 200

17.0 - 22.6

Tank Bracket to Cylinder (1/4'’)

96 - 120

10.9 - 13.6

40 - 60

4.5 - 6.8

140 - 170

15.8 - 19.2

Rope Start Pulley Mounting Screws

60 - 75

6.8 - 8.5

Rocker Arm Box to Cylinder Head

80 - 90

9.0 - 10.2

Rocker Arm Cover and Breather (Screw to Stud)

15 - 20

1.7 - 2.3

Rocker Arm Adjusting Screw Lock Nut

50 - 70

5.5 - 8.0

Rocker Box Cover to Mtg. Stud

20 - 30

2.3 - 3.4

Magneto Stator Mounting Screw

72 - 96

8.1 - 10.9

Blower Housing to Baffle or Cylinder

48 - 72

5.4 - 8.1

Housing Baffle to Cylinder

72 - 96

8.1 - 10.9

Blower Housing Extension to Cylinder

72 - 96

8.1 - 10.9

Governor Rod Clamp to Rod (Screw and Nut)

15 - 25

1.7 - 2.8

Governor Rod Clamp to Lever (Screw and Nut)

15 - 20

1.7 - 2.3

Ground Wire to Terminal

5 - 10

.6 - 1.1

Toggle Stop Switch Nut

10 - 15

1.1 - 1.7

Oil Drain Plug 3/8 18

80 - 100

9.0 - 11.3

Oil Drain Cap

35 - 50

4.0 - 5.7

Hand Tighten

Hand Tighten

Cylinder Head Bolts Connecting Rod Screw or Nut

Starter-Recoil-Top Mount Starter-Electric-Straight Drive

Oil Fill Plug (Large Diameter)

73

CHAPTER 11. EDUCATIONAL MATERIALS AND TOOLS VIDEO PROGRAMS

CARBURETOR TROUBLESHOOTING BOOKLET 695907 This booklet is designed as a quick reference to carburetion problems and related repair procedures.

695015 Carburetor Troubleshooting. Covers identification of carburetors used on Tecumseh engines and how to troubleshoot and repair them. VHS only.

IGNITION SYSTEMS TROUBLESHOOTING BOOKLET 694903

695059 Understanding Tecumseh Ignition Systems. A basic program designed to give the small engine technician first hand knowledge of Tecumseh ignition systems so the technician can understand the system and perform repairs to it. VHS only.

This booklet contains information on the identification, possible problems and related repair procedures of Tecumseh Ignition Systems.

695148 Teardown and reassembly of the 900 series transaxles. This video will show a complete step-by-step procedure for teardown and reassembly of the 900, 910 and 920 series transaxles.

SPECIAL TOOLS BOOKLET 694862 This booklet depicts all specialty tools offered by Tecumseh which can be used on 2 and 4 cycle engines and Peerless units.

695185 Electrical Troubleshooting. This video training program will assist the small engine technician in the proper procedures for troubleshooting electrical systems on outdoor power equipment. 695285 An in-depth look at the 800 series transaxles. Detailing the teardown and reassembly procedures for the 800, 801 and 820 transaxles. SPECIAL BOOKLETS

QUICK REFERENCE CHART BOOKLET 695933 This booklet contains the quick reference information found on Tecumseh wall charts. This booklet is designed to be used as a work bench quick reference guide when servicing Tecumseh engines and motion drive systems.

INSTRUCTIONAL GUIDE 692738 Assists in the use and understanding of the Tecumseh Master Parts Manual. Illustrates time saving features incorporated into the manual. Explains new carburetor parts breakdown format.

TESTER BOOKLETS 694529 Test procedures for Tecumseh electrical components using Graham-Lee Tester 31-SM or 31-SMX-H.

4-CYCLE ENGINE FAILURE ANALYSIS 695590 This booklet is designed as a tool for the average technician to correctly assess the cause of failure.

694530 Test procedures for Tecumseh electrical components using Merco-O-Tronic Tester 9800. (Tests are similar for 98, 98A and 79.)

74

75

TAPER GAP GAUGE

VALVE LAPPING TOOL

No. 670154 - Valve lapping tool. No. 670256 - Taper Gap Gauge

1/32'’ OVERSIZE GUIDE REAMER

No. 670284 - HH & VH80-120 and OH120-180 No. 670305 - Strap Wrench VIBRATION TACHOMETER

No. 670156 - Vibration Tachometer No. 670117 - Ring Expander AIR GAP GAUGE

*No. 670216 - Air gap gauge .0075 (.191 mm) shim stock for setting air gap.

76

TECUMSEH T E C H N I C I A N ' S

H A N D B O O K

This manual covers the following basic type or model numbers dependent on age of product: AH520, AH600, AV520, AV600, HSK600, TVS600. This manual covered many engines under an Old form of Identification which will need to be reviewed as well. TYPE / SPECIFICATION NUMBER 638-670 1398-1642 and Craftsman 200 Series Models.

2-CYCLE ENGINES

Contents Page GENERAL INFORMATION ...................................... 1 ENGINE IDENTIFICATION ................................... 1 INTERPRETATION OF MODEL NUMBER .......... 1 ENGINE CARE ......................................................... 2 SHORT BLOCKS .................................................. 2 STORAGE: ............................................................ 2 TUNE-UP PROCEDURE ...................................... 3 EXHAUST PORT CLEANING .............................. 3 2-CYCLE THEORY OF OPERATION ...................... 4 OPERATION OF PISTON PORT STYLE ............ 4 OPERATION OF REED PORTED STYLE WITH LOOP SCAVENGING .............................. 4 TERMS .................................................................. 4 EXHAUST OR SCAVENGE PHASE .................... 4 PORTS .................................................................. 4 EXHAUST PORTS ................................................ 4 THIRD PORT ........................................................ 4 REED VALVE ........................................................ 4 LUBRICATION ...................................................... 4 AIR CLEANERS, CARBURETORS, GOVERNORS AND LINKAGE ......................................................... 5 AIR CLEANERS .................................................... 5 POLYURETHANE-TYPE AIR CLEANER ............ 5 KLEEN-AIRE® SYSTEM ...................................... 5 PAPER-TYPE AIR CLEANER SERVICE ............. 5 GENERAL CARBURETOR INFORMATION ........... 6 CARBURETOR IDENTIFICATION ....................... 6 FLOAT-TYPE CARBURETORS ........................... 6 DIAPHRAGM (PRESSURE DIFFERENTIAL) CARBURETORS ................................................... 6 OPERATION .......................................................... 7 CARBURETOR SERVICE .................................... 7 THROTTLE ............................................................ 7 CHOKE .................................................................. 8 ADJUSTING SCREWS ......................................... 8 FUEL BOWL RETAINING NUT ............................ 8 CARBURETOR VENTING .................................... 8 HIGH TILT FLOAT STYLE .................................... 8 FUEL BOWL .......................................................... 8 FLOAT ................................................................... 8 INLET NEEDLE AND SEAT (FLOAT CARBURETORS) .............................................. 9 NEEDLE AND SEAT OPO-OFF TEST ................ 9 FLOAT HEIGHT SETTINGS ................................. 9 PRIMER BULB .................................................... 10 CLEANING CARBURETOR BODY .................... 10 DIAPHRAGMS .................................................... 10 INLET NEEDLE AND SEAT ............................... 11 FUEL INLET FITTING ......................................... 11

Page PRIMER BULB (DIAPHRAGM CARBURETOR) ................................................ 11 CARBURETOR CHECK VALVE ......................... 11 CARBURETOR SERVICE PROCEDURE ......... 12 EMISSIONIZED DIAPHRAGM CARBURETION 13 OUTBOARD CARBURETORS .............................. 13 OUTBOARD CONTROL PANEL ........................ 14 CARBURETOR ADJUSTMENTS .......................... 15 IDLE SPEED ADJUSTMENT ............................. 15 FLOAT TYPE-FIXED MAIN, IDLE ADJUST ...... 15 DIAPHRAGM - SINGLE AND DUAL ADJUSTMENT .................................................. 15 TROUBLESHOOTING CARBURETION ............... 16 FLOAT CARBURETOR CHECKS ...................... 16 CHECKS FOR DIAPHRAGM ............................. 16 STANDARD SERVICE CARBURETORS .............. 17 FUEL FITTING .................................................... 17 INLET FUEL FITTING ......................................... 17 CHOKE SHAFT ................................................... 17 THROTTLE LEVER ................................................ 17 IDLE SPEED ADJUSTMENT SCREW .................. 17 GOVERNORS AND LINKAGE .............................. 18 AIR VANE GOVERNORS ................................... 18 OPERATION ........................................................ 18 LINKAGE INSTALLATION ..................................... 18 REWIND STARTERS, ELECTRIC STARTERS AND ALTERNATORS ............................................. 20 REWIND STARTERS .......................................... 20 COMPONENTS ................................................... 20 ROPE SERVICE ................................................. 20 STYLIZED REWIND STARTER ......................... 21 VERTICAL PULL STARTER HORIZONTAL ENGAGEMENT TYPE ........................................ 22 STYLIZED REWIND STARTER WITH PLASTIC RETAINER ........................................................ 23 VERTICAL PULL STARTER, VERTICAL ENGAGEMENT TYPE ...................................... 24 REWIND STARTER MOUNTED IN HOUSING . 25 ELECTRIC STARTERS .......................................... 26 DRIVE ASSEMBLY SERVICE ............................ 26 STARTER CHECKING AND SERVICE ............. 27 CHECK FIELD ..................................................... 27 ARMATURE CHECK ........................................... 27 TROUBLESHOOTING STARTERS ....................... 27 ALTERNATORS ...................................................... 28 CHECKING THE SYSTEM ................................. 28 FLYWHEEL (INSIDE-EDGE) BRAKE SYSTEM ... 29 INSIDE EDGE SYSTEM ..................................... 29 COMPONENTS ................................................... 29 SERVICE ............................................................. 29 CONTROL CABLE .............................................. 30

Copyright © 1994 by Tecumseh Products Company All rights reserved. No part of this book may be reproduced or transmitted, in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without permission in writing from Tecumseh Products Company Training Department Manager. i

Page IGNITION ................................................................. 31 IGNITION OPERATION (Pre- 1985 Production) ........................................................ 31 MAGNETO IGNITION ......................................... 31 CONTACT POINTS ............................................. 31 CONDENSER ..................................................... 31 OPERATION OF THE TECUMSEH MAGNETO IGNITION ....................................... 31 SOLID STATE IGNITION (1985 to Present) ...... 32 SOLID STATE IGNITION OPERATION ............. 32 IGNITION SERVICE ............................................... 33 SPARK PLUG SERVICE .................................... 33 FLYWHEEL REMOVAL AND SERVICE ............. 33 FLYWHEEL MAGNETS ...................................... 33 FLYWHEEL KEYS ............................................... 34 ADAPTER KEY TO FLYWHEEL ASSEMBLY .... 34 FLYWHEEL SLEEVE .......................................... 34 FLYWHEEL TORQUE ......................................... 34 REPLACING MAGNETO BREAKER POINTS .. 34 CONDENSER CHECK ....................................... 34 IGNITION COIL ................................................... 34 IGNITION TIMING .............................................. 34 FIXED TIME SPEED (EXTERNAL COIL) .......... 36 SOLID STATE (CDI) ........................................... 36 OTHER IGNITION SYSTEMS ............................ 36 OUTBOARD TIMING .............................................. 38 OUTBOARD TIMING (STANDARD IGNITION) . 38 OUTBOARD TIMING (SOLID STATE) ............... 39 CYLINDERS & INTERNAL COMPONENTS ......... 41 PISTON & RING SERVICE ................................ 41 CONNECTING ROD SERVICE .............................. 42 NEEDLE BEARINGS .......................................... 42 CRANKSHAFT, BEARING AND OIL SEAL SERVICE ................................................................. 43 NEEDLE BEARINGS .......................................... 43

Page OIL SEALS .......................................................... 43 ONE PIECE SEALS ............................................ 43 THREE PIECE SEALS ....................................... 44 OUTBOARD SEAL SERVICE ............................ 44 CYLINDERS, REEDS & COMPRESSION RELEASE ................................................................ 45 CYLINDER & HEAD SERVICE .......................... 45 GASKETS ............................................................ 45 REED VALVES .................................................... 45 AUTOMATIC COMPRESSION RELEASE (DOUBLE REED TYPE) ................................. 45 AUTOMATIC COMPRESSION RELEASE (SINGLE REED TYPE) ................................... 45 CYLINDER EXHAUST PORTS .......................... 46 TROUBLESHOOTING ............................................ 47 ENGINE FAILS TO START OR STARTS WITH DIFFICULTY ............................................. 47 ENGINE KNOCKS .............................................. 47 ENGINE MISSES UNDER LOAD ...................... 48 ENGINE LACKS POWER ................................... 48 ENGINE OVERHEATS ....................................... 48 ENGINE SURGES OR RUNS UNEVENLY ....... 49 ENGINE VIBRATES EXCESSIVELY ................. 49 SPECIFICATIONS .................................................. 50 ENGINE TYPE NUMBER AND LETTER REFERENCE ................................................... 50 SEARS CRAFTSMAN CROSS REFERENCE ...... 51 TABLE OF SPECIFICATIONS ....................... 52 - 61 TABLE OF TORQUE LIMITS ................................. 62 EDUCATIONAL MATERIALS AND TOOLS ......... 63 AVAILABLE TECHNICIAN'S HANDBOOKS ...... 63 AVAILABLE FOREIGN TECHNICIAN'S HANDBOOKS .................................................. 63 TOOL KIT 670195D ................................................ 64 TOOLS ..................................................................... 65

This manual contains information on Tecumseh Engines built to comply with emission regulations. As a technician it is unlawful to modify or cause a change in the original calibration of these engines. All speed adjustments must remain within the limits that are specified for each engine, and are not to exceed the maximum. Any deviation must be specifically approved by Tecumseh Products Company.

ii

GENERAL INFORMATION ENGINE IDENTIFICATION

Tecumseh has used two different methods of identifying 2 cycle engines. The first method was used until the mid 1980's using the base model number with a type number. The type number was used to identify variations for the OEM's specific needs (Fig. 1) T-670 TECUMSEH 6874603

5 30 75

FRONT SIDE

REVERSE SIDE (BUILD DATE)

TYPE

Following the engine size are the engine specification numbers which are used for identification when ordering parts. The final set of numbers are the date of manufacture (D.O.M.). Example: HSK600 1688S HSK 600 1688S 8023B

SERIAL NUMBER 1975 YEAR

8

30th DAY 5th. MONTH (MAY)

023 B

1401J TECUMSEH 6219

TYPE SERIAL NUMBER

YEAR 219th DAY 1976 or Aug. 6th

670-100 TECUMSEH 62290322

TYPE

-

Horizontal Snow King 6 Cubic Inch displacement Specification number Serial number D.O.M. (date of manufacturing previously serial number) - First digit is the year of manufacturing (1998) - Indicates the calendar day of the year (23th day or Jan. 23, 1998) - Represents the line and shift on which the engine was built at the factory

SERIAL NUMBER

YEAR 229th DAY 1976 or Aug. 17th

1

FUEL REGULAR UNLEADED FUEL/OIL MIX 32:1 HSK600-1688S

The second method was put in place to standardize 2 cycle and 4 cycle engine identification. The type number has now become the specification number, which is preceded by the engine model as illustrated in Figure 2 and 3.

8023B

TVS600-661030M 7352

3

T 66 VS6 1 00 73 030M 52

Tecumseh engine model, specification, and D.O.M. number are now located on a decal adhered to the blower housing.

2

INTERPRETATION OF MODEL NUMBER The letter designations in a model number indicates the basic type of engine. AH AV BV HSK TVS

-

Aluminum Horizontal Aluminum Vertical Outboard Vertical Horizontal Snow King Tecumseh Vertical Styling

The numbers that follow the letter designations indicate the horsepower or cubic inch displacement.

FUEL REGULAR UNLEADED FUEL/OIL MIX 32:1 HSK600-1688S 8023B

4

1

ENGINE CARE SHORT BLOCK IDENTIFICATION TAG SBV OR SBH IDENTIFICATION NUMBER

SBV-2316

Clean gas cap, tank and fuel container spout when filling fuel tank, to assure that dirt will not get into fuel system. If gasohol is used, special care is required when the engine is to be stored for extended periods.

SER 4291

ENGINE OIL. Use Clean, high quality 2 CYCLE OIL. NMMA TC-WII, or TC-W3.

SERIAL NUMBER

SHORT BLOCKS

New short blocks are identified by a tag marked S.B.H. (Short Block Horizontal) or S.B.V. (Short Block Vertical). Original model identification numbers of an engine should always be transferred to a new short block for correct parts identification. THIS SYMBOL POINTS OUT IMPORTANT SAFETY INSTRUCTIONS WHICH IF NOT FOLLOWED COULD ENDANGER THE PERSONAL SAFETY OF YOURSELF AND OTHERS. FOLLOW ALL INSTRUCTIONS.

U.S.

Using fuel that is not fresh will cause engines to be hard starting, especially in cold temperatures.

ENGINE FUEL MIX

U.S. METRIC METRIC Amount of Oil Amount of Oil Gasoline To Be Added Petrol To Be Added 24:1 1 Gallon 5.3 oz. 4 Liters 167 ml 2 Gallons 10.7 oz. 8 Liters 333 ml 32:1 1 Gallon 2 Gallons

4 oz. 8 oz.

4 Liters 8 Liters

125 ml 250 ml

50:1 1 Gallon 2 Gallons

2.5 oz. 5.0 oz.

4 Liters 8 Liters

80 ml 160 ml

FUELS. Tecumseh Products Company strongly recommends the use of fresh, clean, UNLEADED regular gasoline in all Tecumseh Engines. Unleaded gasoline burns cleaner, extends engine life and promotes good starting by reducing the build up of carbon deposits. Premium gas or gasohol containing no more than 10% ethanol can be used if unleaded fuel is not available. NOTE: NEVER USE GASOLINE CONTAINING METHANOL, GASOHOL CONTAINING MORE THAN 10% ETHANOL, UNLEADED REGULAR GASOLINE CONTAINING MORE THAN 15% M.T.B.E. OR ETBE, GASOLINE ADDITIVES, OR WHITE GAS BECAUSE ENGINE/FUEL SYSTEM DAMAGE COULD RESULT.

FUEL/OIL MIX. Follow fuel and engine oil requirements listed in the Owner’s Manual. Disregard conflicting instructions found on oil containers. NOTE: Sears Craftsman models use a 40:1 mix which is acceptable. NOTE: ALWAYS DOUBLE THE AMOUNT OF OIL FOR THE FIRST GALLON OF MIX FOR ENGINE BREAK IN. To assure thorough mixing of oil and gasoline, fill container with gasoline to one quarter full, add oil as recommended, shake container vigorously and then add remainder of gasoline. Do not mix directly in engine or equipment fuel tank. TWO-CYCLE FUEL/OIL MIX RATIOS 24:1 AV520 All Basic Specifications 670 & 653 AV600 All Basic Specifications 600-10 & Up 32:1 TVS600 All Specifications AH600 50:1 HSK600

STORAGE: NEVER STORE ENGINE WITH FUEL IN TANK INDOORS OR IN ENCLOSED, POORLY VENTILATED ENCLOSURES WHERE FUEL FUMES MAY REACH AN OPEN FLAME, SPARK OR PILOT LIGHT AS ON A FURNACE, WATER HEATER, CLOTHES DRYER, ETC. If engine is to be stored over 30 days, prepare for storage as follows: 1. Remove all gasoline from fuel tank to prevent gum deposits from forming in tank and other fuel system components, causing possible malfunction of the engine.

NOTE: In countries where unleaded gasoline is not available, regular gas can be used.

DRAIN FUEL INTO APPROVED CONTAINER OUTDOORS, AWAY FROM OPEN FLAMES.

Make sure that gasoline and oil are stored in clean, covered, rust free containers. Dirt in fuel can clog small ports and passages in the carburetor. Use fresh gasoline only. Gasoline standing for long periods of time develop a gum that will result in fouled spark plugs, clogged fuel lines, carburetors and fuel screens. 2

Run engine until fuel tank is empty and engine stops due to lack of fuel. Fuel stabilizer (such as Tecumseh's Part No. 730245) is an acceptable alternative in minimizing the formation of fuel gum deposits during storage.

Add stabilizer to fuel in fuel tank or storage container. Always follow mix ratio found on stabilizer container. Run engine at least 10 minutes after adding stabilizer to allow it to reach carburetor. If gasohol has been used, complete preceding instructions and then add a small amount, one pint or less, of unleaded regular automotive gasoline properly mixed with the specified lubricating oil and run the engine until the fuel tank is empty and the engine stops due to lack of fuel. 2. Pull starter handle slowly until resistance is felt due to compression pressure, then stop. Release starter tension slowly to prevent engine from reversing due to compression pressure. This position will close both the intake and exhaust ports to prevent corrosion of the piston and the cylinder bore. 3. Clean unit by removing any dirt from exterior of the engine and equipment.

8. Fill tank with the proper fuel/oil mix. 9. Start the engine, allow it to warm up 5 minutes, then adjust carburetor and engine R.P.M. according to Tecumseh’s recommendations. Snow King ® engines should be run in outdoor temperatures for engine adjustments. NOTE: Emissionized engines have non-adjustable carburetors in compliance with CARB (California Air Resource Board) and U.S. EPA (United States Environmental Protection Agency). These engines can not be modified without specific authorization.

COMPRESSION RELEASE PASSAGE

TUNE-UP PROCEDURE. The following is a minor tuneup procedure. Repair procedures for this engine and it’s components are listed in this manual if the engine does not perform to satisfaction after tune-up is performed. CAUTION: Remove spark plug wire before doing any service work on engine. 1. Service or replace air cleaner as necessary. NOTE: Snow King® engines do not use an air filter due to the clean operating environment and to prevent filter freeze-up. 2. Remove blower housing, clean all dirt, grass or debris from air intake screen, cylinder cooling fins, and carburetor governor levers and linkage. 3. Remove carburetor, clean and install a carburetor kit, make adjustment presets where needed. Presets are found in the carburetor section of this manual. Make sure fuel tank, fuel filters and fuel lines are clean. Reinstall carburetor, replacing any worn or damaged governor springs or linkage. Make proper governor adjustment. Adjustments are found in the manual under governor linkage and adjustment and engine reassembly.

EXHAUST PORT CLEANING. The exhaust ports should be cleaned after each seventy-five (75) to one hundred (100) hours of use. Before cleaning the ports place the piston in the Bottom Dead Center position. Then clean the ports using a pointed 3/8'’ diameter wooden dowel or similar tool. Be sure not to scratch the port area. Also remember to remove all the loose carbon particles from the engine. NOTE: When cleaning the exhaust ports, check and clean the compression release passage.

4. Replace the spark plug with a correct equivalent. 5. Make sure all ignition wires are properly routed, so they will not rub on flywheel. Inspect all ignition wires for abrasion or damage. Remove flywheel and check flywheel key, reinstall flywheel, torque flywheel nut to specifications. Set air gap between solid state module and flywheel at .0125'’. Air gap gauge, part no. 670297 may be used. 6. The engine must be firmly mounted to the associated equipment. On rotary lawnmowers, make sure blade is properly balanced and correctly torqued. See disassembly section for flywheel removal and air gap setting procedure. 7. Make sure all remote linkage is properly adjusted for operation. 3

2-CYCLE THEORY OF OPERATION Air cooled 2-cycle engines differ from 4-cycles by having one power stroke for every revolution of the engine versus every other stroke on 4-cycles.

1.

INTAKE AND IGNITION

2.

COMPRESSION

As the mixture flows into the combustion chamber through the transfer ports, it collides and is directed to the top of the combustion chamber looping when it strikes the cylinder head, thus forcing all spent gases out through the open exhaust ports. TERMS. Listed are common terms often referred to on 2-cycle engines.

3.

POWER

4.

EXHAUST or SCAVENGE PHASE. The burned gases must be cleared out of the combustion chamber and replaced by a fresh charge of fuel-air mixture through the intake ports. The exhaust passes out through the exhaust ports into the outside air. PORTS. Openings in the cylinder allow gases to pass into and out of the combustion chamber. The ports are opened or closed by the upward and downward movement of the piston. EXHAUST PORTS. Allow the burned gases to pass out of the combustion chamber.

OPERATION OF PISTON PORT STYLE. A low pressure area is created in the crankcase as the piston moves upward to compress the air/fuel mixture in the cylinder. When the piston moves far enough to uncover the intake port, the air/fuel mixture from the carburetor flows into the engine crankcase due to higher pressure atmospheric air. Just before the piston reaches top dead center (TDC), the spark plug ignites the air / fuel mixture in the cylinder. The expanding combustion gases force the piston down. The downward piston travel causes a pressure buildup in the crankcase. The piston uncovers the exhaust port first, followed by the transfer ports. The exhaust flows out the exhaust port while the pressurized air/ fuel mixture enters the cylinder from the crankcase through the transfer ports. As the piston travels upward the sequence is repeated.

OPERATION OF REED PORTED STYLE WITH LOOP SCAVENGING The following illustrates the loop scavenge design which uses a vacuum-pressure activated reed valve. Here the ports are located on three sides of the cylinder; the intake ports are on two sides opposite each other, and the exhaust ports are illustrated by the three holes just above the head of the piston.

4

THIRD PORT (Sometimes called piston port). A third port is for entry of the fuel-air and oil mixture to the crankcase. From the crankcase the fuel-air mixture enters the combustion chamber through the intake ports. The third port is controlled by the piston skirt. REED VALVE. A reed valve is activated by crankcase pressure or vacuum. A decrease in crankcase pressure opens the reed allowing the fuel air and oil mixture to enter the crankcase. Increased crankcase pressure closes the valve, preventing escape of the fuel-air and oil mixture back through the carburetor. LUBRICATION. Tecumseh 2-cycle engines are lubricated by a gas oil mix. The correct mix ratio of oil and gas combines with air in the venturi and enters the crankcase. During engine operation the oil clings to all the internal moving parts for lubrication.

AIR CLEANERS, CARBURETORS, GOVERNORS AND LINKAGE AIR CLEANERS Service the air cleaner frequently to prevent clogging of the cleaner and to prevent dust and dirt from entering the engine. Dust bypassing an improper or damaged air filter can quickly damage an engine. Always make certain covers and air cleaner connections are tightly sealed to prevent entry of dirt.

CUPPED SCREEN MUST BE POSITIONED WITH EDGES AWAY FROM ELEMENT

COVER

NOTE: Snow King ® models do not use air cleaners due to the clean environment that they operate in and also to prevent air cleaner freeze-up. When excessive carburetor adjustment or loss of power results, inspect the air filter for clogging. NOTE: Use factory recommended parts only. POLYURETHANE-TYPE AIR CLEANER. These serviceable air cleaners utilize a polyurethane element which will clog up with use. The element should be cleaned and serviced in the following manner. Wash element in a detergent and water solution and squeeze (don’t twist) until all dirt is removed. Rinse thoroughly.

POLYURETHANE ELEMENT FLOCKED SCREEN

KLEEN-AIRE ® SYSTEM. This system uses a polyurethane type element. Service as described under polyurethane-type air cleaner. When removing air cleaner body from carburetor, remove plug in the body to gain access to the mounting screw. Make certain plug is put back in place. If it shows damage, replace. POLYURETHANE ELEMENT

Wrap in clean cloth and squeeze (don’t twist) until completely dry. Clean air cleaner housing and cover. Dry thoroughly. Re-oil element by applying generous quantity of oil to all sides. Squeeze vigorously to distribute oil and to remove excess oil. (S.A.E. 30)

PLUG MUST BE IN PLACE FLOCKED SCREEN

PAPER-TYPE AIR CLEANER SERVICE. Replace air filter once a year or more often in extremely dusty or dirty conditions. DO NOT ATTEMPT TO CLEAN OR OIL PAPER-TYPE FILTER. Be sure to clean base and cover thoroughly before installing new paper filter. When reassembling polyurethane oval type air cleaners, place cupped screen into housing with edge against carburetor end of housing. Screen should be installed to hold element away from housing to allow full utilization of air cleaner element. NOTE: Polyurethane type filters will lose effectiveness if stored for extended periods of time, due to oil migration (settling Down) through the filter. Re-oil filter as necessary.

NEVER RUN THE ENGINE WITHOUT THE COMPLETE AIR CLEANER INSTALLED ON THE ENGINE. NOTE: Serious damage to the engine may result in using any other but the specified part number filter. Use factory recommended parts only.

5

GENERAL CARBURETOR INFORMATION CARBURETOR IDENTIFICATION. Tecumseh carburetors are identified by a manufacturing number and code date stamped on the carburetor as illustrated. ALTERNATE LOCATION FOR MANUFACTURING NUMBER

F5 89 4

89

CARBURETOR MANUFACTURING NUMBER

4F5

CARBURETOR CODE DATE

When servicing carburetors, you may use either the engine model specification number or the manufacturing number on the carburetor to properly identify. Information regarding replacement parts or kits are available in the master parts manual, microfiche catalog or electronic parts look-up systems. Tecumseh uses two basic types of carburetors for their 2 cycle engines, float-type and diaphragm. FLOAT-TYPE CARBURETORS. Float-type carburetors use a hollow metal float to maintain the operating level of fuel in the carburetor. As the fuel is used, the fuel level in the carburetor bowl drops and the float moves downward. This actuates the inlet needle valve, to allow fuel to flow into the fuel bowl. As the fuel level in the bowl again rises, so will the float. This float action adjusts the fuel flow and keeps the fuel at the proper mixture level. Some carburetors are of the fixed main type. On these models, the main adjusting screw and nut are replaced by a fixed main jet bowl nut. THROTTLE SHUTTER SECONDARY IDLE DISCHARGE PRIMARY IDLE DISCHARGE *IDLE ADJUSTMENT SCREW IDLE FUEL TRANSFER PASSAGE REDUCTION ROD

IDLE FUEL CHAMBER

IDLE AIR BLEED

CHOKE SHUTTER

AIR BLEED INLET SEAT INLET NEEDLE FLOAT

IDLE FUEL *MAIN ADJUST TRANSFER PASSAGE *Both jets may be fixed - non adjustable

6

DIAPHRAGM (PRESSURE DIFFERENTIAL) CARBURETORS This type of carburetor uses a rubber-like diaphragm which is exposed to intake manifold pressure on one side and to atmospheric pressure on the other. Tecumseh diaphragm carburetors use the diaphragm as a metering device. As the intake manifold pressure decreases due to downward piston travel, the atmospheric pressure on the vented side of the diaphragm moves the diaphragm against the inlet needle. The diaphragm movement overcomes the spring tension on the inlet needle and moves the inlet needle off the seat. This permits the fuel to flow through the inlet valve to maintain the correct fuel volume in the fuel chamber. The inlet needle return spring closes the inlet valve when the pressure on the diaphragm equalizes or a pressure higher than atmospheric exists on the intake side (upward piston travel). The diaphragm meters a correct fuel volume in the fuel chamber to be delivered to the mixing passages and discharge ports. A main or idle adjustment needle may be replaced by an internally fixed jet on some models. The main nozzle contains a ball check valve. The main purpose of this ball check is to eliminate air being drawn down the main nozzle during idle speeds and leaning the idle mixture. An advantage of the diaphragm carburetor over the float system is that the diaphragm carburetor increases the angle that the engine may be operated at. AIR BLEED

CHECK BALL

IDLE AND INTERMEDIATE PORTS

CHOKE SHUTTER

THROTTLE SHUTTER IDLE ADJUST

FUEL INLET

MAIN ADJUST

DIAPHRAGM

INLET NEEDLE AND SEAT

OPERATION In the “CHOKE” or “START” position, the choke shutter is closed, and the only air entering the engine enters through openings around the shutter. As the engine starts to rotate the downward piston travel will create a low air pressure area in the engine cylinder above the piston. Higher pressure (atmospheric air) rushes into the engine to fill the created low pressure area. Since the majority of the air passage is blocked by the choke shutter, a relatively small quantity of air enters the carburetor at increased speed. The main nozzle and both idle fuel discharge ports are supplying fuel due to the low air pressure in the intake of the engine. A maximum fuel flow through the carburetor orifices combined with the reduced quantity of air that passes through the carburetor, make a very rich fuel mixture which is needed to start a cold engine. At engine IDLE speed, a relatively small amount of fuel is required to operate the engine. The throttle is almost completely closed. A fuel / air mixture is supplied through the primary idle-fuel discharge orifice during idle. During INTERMEDIATE engine operation, a second orifice is uncovered as the throttle shutter opens, and more fuel mixture is allowed to atomize with the air flowing into the engine. During HIGH SPEED engine operation, the throttle shutter is opened. Air flows through the carburetor at high speed. The venturi, which decreases the size of the air passage through the carburetor, further accelerates the air flow. This high speed movement of the air decreases the air pressure at the main nozzle opening. Fuel is forced out the main nozzle opening due the difference in the atmospheric air pressure on the fuel in the carburetor bowl and the reduced air pressure at the main nozzle opening. CARBURETOR SERVICE. Carefully disassemble carburetor, removing all non-metallic parts, i.e., gaskets, viton seats and needles, “O” rings, fuel pump valves, etc. Nylon check balls used in some diaphragm carburetors are not serviceable. Nylon can be damaged if subjected to harsh cleaners for prolonged periods. Remove the primer bulb (if equipped) by grasping with a pliers and pulling and twisting out of the body. Remove the retainer by prying and lifting out with a screwdriver. Do not re-use old bulb or retainer.

Remove all welch plugs if cleaning the carburetor. Secure the carburetor in a vise equipped with protective jaws. Use a small chisel sharpened to a 1/8" wide wedge point. Drive the chisel into the plug to pierce the metal and push down on the chisel to pry the plug out of the hole. Clean all metallic parts with solvent. SMALL CHISEL PRY OUT PLUG DO NOT ALLOW CHISEL POINT TO STRIKE CARBURETOR BODY OR CHANNEL REDUCER

PIERCE PLUG WITH TIP

WELCH PLUG TO BE REMOVED

ABOUT 1/8" WIDE

SMALL CHISEL

To install a new welch plug after cleaning, place welch plug into receptacle with raised portion up. With a punch equal to the size of the plug, merely flatten the plug. Do not dent or drive the center plug below the top surface of the carburetor. After installing the welch plug, seal the outer diameter with finger nail polish. (Do not use clear polish).

FLAT-END PUNCH

NEW WELCH PLUG

SAME OR LARGER DIAMETER OF PLUG

THROTTLE. Examine the throttle lever and plate prior to disassembly. Replace any worn and/or damaged parts. When reassembling, it is important that the lines on the throttle plate are facing out when in the closed position. Position throttle plates with the two lines at 12 and 3 o’clock. If throttle plate has only one line, the line should be positioned in the 12 o’clock position. If binding occurs, correct by loosening the screws and repositioning the throttle plate. THROTTLE LEVER

THROTTLE PLATE

7

CHOKE. Examine the choke lever and shaft at the bearing points and holes into which the linkage is fastened, and replace if worn or damaged. The choke plate is inserted into the air horn of the carburetor in such a position, that the flat side of the choke is down. Before disassembly note the direction of choke plate movement. Choke plates will operate in either direction. Make sure it is assembled properly for your engine. CHOKE PLATE

FUEL BOWL. The fuel bowl must be free of dirt and corrosion. When disassembling a carburetor for repair, always replace the fuel bowl “O” ring. Lubricate the “O” ring with a small amount of oil for easier installation. Install the float bowl by placing the detent portion opposite of the hinge pin. Make sure the deepest end of the bowl is opposite of the inlet needle. The bowl has a small dimple located in the deepest part. The purpose of this dimple is to minimize the chances of the float sticking to the bottom of the bowl caused by stale fuel.

DETENT

DOWN TOWARD FUEL BOWL

ADJUSTING SCREWS. Remove the adjusting screws from the carburetor body and examine the point, replace the screws if damaged. Tension is maintained on the screw with a coil spring. Examine and replace the “O” ring seal(s) if damaged. NOTE: If screws are made of plastic, dip the end of the screw in oil before installation to prevent damage. FUEL BOWL RETAINING NUT. The fuel bowl retaining nut has a fixed main jet incorporated in the nut. This small jet must be clean for proper fuel metering. Clean by using compressed air. DO NOT USE WIRE OR HARD OBJECTS FOR CLEANING. CARBURETOR VENTING. Float-type carburetors must have atmospheric air pressure acting against the fuel in the fuel bowl. These vents can be external, with a hole drilled through the side of the carburetor casting or internal where atmospheric air is picked up in the air horn near the air cleaner. Regardless of the type, these vents must be clear and free from dirt, paint, grease, etc.

FLOAT. Remove the float by pulling out the float hinge pin. Lift the float away from the carburetor body. This will also lift the inlet needle out of the seat. Examine the float for damage. Check the float hinge bearing surfaces for wear, as well as the tab that contacts the inlet needle. Replace any damaged or worn parts. EXAMINE FLOAT HINGE FOR WEAR AT BEARING SURFACES INLET NEEDLE

INLET NEEDLE CLIP

HIGH TILT FLOAT STYLE carburetors use an external main air bleed.

MAIN AIR BLEED

REMOVE FLOAT TO MAKE ADJUSTMENTS. BEND THIS TAB TO ADJUST

Float sticking can occur due to fuel deposits (gum or varnish). This can be corrected by loosening the carburetor bowl nut one full turn and rotating the bowl 1/4 turn in either direction. Return the bowl to it's original position and retighten the bowl nut.

8

INLET NEEDLE AND SEAT (FLOAT CARBURETORS). Tecumseh carburetors are built with removable seats made out of a material called VITON ®. These seats are easily removed by bending the end of a paper clip or wire with a 3/32" hook or use a #4 crochet hook. Push the hook through the hole in the center of the seat and remove it. Never reuse the old seat, always replace it with a new seat.

If the required adjustment is minor, the tab adjustment may be made without removing float and carefully inserting a small bladed screwdriver to bend the tab. Be careful not to damage other parts.

11/64" DRILL BIT

3/32" HOOK END

RIM

To install a new seat, make sure the seat cavity is clean, then moisten the seat with a drop of oil to help it slide into place. Position the seat with the grooved side of the seal down and carefully push the seat into its cavity with a 5/32" flat punch until it bottoms out. NEEDLE AND SEAT POP-OFF TEST To test the pop-off pressure, remove the carburetor from the engine. Be sure to drain any fuel into an approved container. Invert the carburetor and remove the float bowl. Place a drop of an oil based product such as WD-40 on the tip of the needle valve. Using a commercially available 0-30 psi pump and gauge, attach the pumps hose to the carburetor inlet. Apply approximately 6 psi or until the needle pops off the seat. The needle should seat at 1.5 psi or greater for a minimum of 5 minutes. If the minimum 1.5 psi cannot be maintained for this period of time, then service to the needle and seat is required.

The idle on the Series 8 is metered using a threaded restrictor (See illustration). Proper torque of this restrictor is critical, it should be torqued to 5-8 in. lbs. or .5 to 1 nm, or it may vibrate loose. When the restrictor is placed in the idle circuit passage it is capped with a tamper resistant plastic cap. If the jet is removed for cleaning it must be recapped to prevent tampering when it is re-installed.

IDLE RESTRICTOR CAP

The inlet needle hooks onto the float tab by means of a spring clip. To prevent binding, the long, straight, open end of the clip must face the choke end of the carburetor as shown.

5/32" FLAT PUNCH DRIVE IN UNTIL SEAT RESTS ON BODY SHOULDER

INLET NEEDLE SEATS AT THIS POINT

CLIP

SEAT

INSERT THIS FACE FIRST

LONG END OF CLIP

THROTTLE END

FLOAT HEIGHT SETTINGS Previously the float height was set by using a 670253A float setting tool. The new float setting will require an 11/64" drill bit. The procedure for setting the float height is as follows. Remove the bowl gasket, then hold the carburetor in the inverted position. Place the drill bit across the carburetor body opposite and parallel to the float hinge pin. Adjust the float height by bending the tab on the float until it touches the bit.

CHOKE END

9

The float dampening spring on the HIGH TILT FLOAT STYLE carburetor has an extended end which must point toward the choke end of the carburetor. POINTS TOWARD CHOKE END

FLOAT DAMPENING SPRING

PRIMER BULB. To install, start the retainer and bulb into the casting with the retainer tabs pointed out. Firmly push the bulb and retainer into position using a 3/4" (19mm) deep well socket.

MAIN NOZZLE DO NOT ATTEMPT TO REMOVE

cleaner and compressed air. With the choke plate and shaft removed, blow compressed air through the high speed air bleed located just behind the lower choke shaft bearing and immediately in front of the venturi to remove any dirt that may have accumulated. Blow compressed air through all of the passages, making sure they are free of dirt, varnish or foreign material. DIAPHRAGMS. Inspect diaphragms for cracks, tears or brittleness. Replace if necessary. Rivet head on diaphragm must always face toward the inlet needle valve. If the carburetor has an "F" designation on the casting, it will identify the installation sequence of the gasket and diaphragm on the carburetor. "F" designated carburetors have the diaphragm installed first then the gasket then the cover. If there is no designation, the sequence is gasket, diaphragm and cover.

CLEANING CARBURETOR BODY. When removing choke and throttle shafts, check shafts and bearings in carburetor body for wear. Any looseness in these areas can cause dirt to enter the engine resulting in premature wear. If dust seals are present, they should be positioned next to the carburetor body. Install the dust seal, metal washer, and finally the return spring. Welch plugs should be removed for proper cleaning of the carburetor (See welch plug service at the beginning of this section). When all accessories and shafts have been removed, soak the carburetor in carburetor cleaner for a maximum of 30 minutes. Blow out all passages with compressed air in the opposite direction of normal fuel flow. The carburetor body on non-emission carburetors contains a main nozzle tube pressed into the carburetor body to a predetermined depth within the venturi of the carburetor. DO NOT attempt to remove this main nozzle. Any movement of this nozzle will seriously affect the metering characteristics of the carburetor. (Emissions carburetors have a serviceable plastic nozzle.) Clean the well surrounding the main nozzle with carburetor

10

INLET NEEDLE AND SEAT. (Diaphragm Carburetors)

GASKET

RIDGE AND RIVET HEAD UP

RIDGE AND RIVET HEAD UP GASKET

Use a socket to remove inlet needle and seat. Replace with complete assembly. FUEL INLET FITTING. If necessary this fitting can IDLE MIXTURE SCREW MAIN MIXTURE SCREW

with primers must have a check valve located in or behind the fuel inlet fitting of the carburetor. This is to prevent fuel from being forced back to the fuel line and tank when priming. Two types of check valves have been used. One is a brass check valve pushed into the carburetor body in the fuel inlet. The other is a teflon disc located in the area under the fuel fitting. These two types of check valves are not interchangeable. To remove the brass type check valve, drill a 9/64'’ (3.57 mm) hole through the center of the check valve, making sure drill does not travel more than 1/8'’ (3.17 mm) into the body and damage the carburetor. Turn a nut on to a 8-32 tap and slide a washer on after it.

be removed by pulling and twisting. Be sure to install in the same position as the original. When installing fitting, insert tip into the carburetor body, then coat the exposed portion of the shank with Loctite 242 Blue; then press it in, until the shoulder contacts the carburetor body.

Turn the tap with nut and washer into the valve until the tap begins to protrude through the valve when viewed through the inlet needle and seat opening. Turn the nut clockwise to pull the valve out from the carburetor body.

THE PRIMER BULB (DIAPHRAGM CARBURETOR).

8-32 TAP

PRESS IN PARTIALLY THEN APPLY LOCTITE "242 BLUE"

WASHER

Pressing the bulb creates air pressure against the diaphragm. Fully depress primer bulb with your thumb, making sure that the vent hole in bulb is covered. Release and allow bulb to return to original position.

The teflon disc-type can be cleaned by using low air pressure forced into the inlet fitting. If service is required, pull out inlet fuel fitting and replace the teflon disc. Put a drop of oil on the disc and position in the cavity of the carburetor. Replace fuel inlet fitting as outlined in Fuel Inlet Fitting instructions.

As the diaphragm lifts, the inlet needle is lifted off its seat and the fuel within the reservoir is fed up through the passages into the air horn. A one-way valve in the body prevents the fuel from being forced back into the fuel tank. CARBURETOR CHECK VALVE. Diaphragm carburetors TEFLON PUSH

BRASS

RELEASE

11

CARBURETOR SERVICE PROCEDURE THROTTLE SHAFT AND LEVER Check shaft for looseness or binding. Shutter must be positioned with THROTTLE SHUTTER detent reference mar ks on top parallel with shaft. DETENT REFERENCE MARK

IDLE SPEED ADJUSTMENT SCREW

MAIN NOZZLE

Loosen screw until it just clears throttle lever, then turn screw in 1 turn. Do not attempt to remove. Blow air through passage.

CHOKE SHAFT AND LEVER Check shaft for binding. CHOKE PLATE Check spring for return action and binding.

THROTTLE SHAFT RETURN SPRING

MAIN NOZZLE AIR BLEED

Remove when cleaning and replace DUST SEALS with new seals.

Blow air through passage. Do not remove restrictor if present.

INLET FITTING

*INLET NEEDLE AND SEAT

*FLOAT BOWL GASKET

SOFT BAFFLE PLUG

Proper installation is important. See appropriate chapter for procedures.

Replace.

FLOAT SHAFT Clean with compressed air.

Clean with compressed air.

FUEL PICK UP

INLET NEEDLE CLIP

FLOAT

MAIN JET

FLOAT BOWL BOWL NUT

*GASKET

Must hook over float tab. Long straight end of clip must face the choke end of the carburetor.

Check float for leaks or dents. Clean bowl and adjust float level position gasket or gaskets. Set float to proper level.

*NON METALLIC ITEMS - CAN BE DAMAGED BY HARSH CARBURETOR CLEANERS

Loosen screw until it just clears throttle lever, then turn screw in 1 IDLE SPEED ADJUSTMENT SCREW turn.

CHOKE SHAFT AND LEVER Check shaft for binding. Position shutter opening towards inlet fitting CHOKE SHUTTER side of air horn.

THROTTLE SHAFT AND LEVER Place detent reference mark to DETENT REFERENCE MARK proper location. See chapter ON THROTTLE SHUTTER appropriate to specific carburetor. THROTTLE SHUTTER Check spring for return action and THROTTLE SHAFT RETURN SPRING binding. Primer bulb models have a Teflon *INLET FITTING one way valve, in or behind the fitting.

IDLE, Remove welch plug and blow air INTERMEDIATE through air passages. AND AIR BLEED ORIFICES

*INLET SEAT Remove and replace. GASKET

FUEL *IDLE MIXTURE ADJUSTMENT SCREW AND "O" RING (If Present) *MAIN MIXTURE ADJUSTMENT SCREW AND "O" RING (If Present)

The check ball is a non serviceable item. Clean with carburetor spray and *MAIN NOZZLE WITH CHECK BALL low air pressure only.

*INLET NEEDLE SEAT AND SPRING ASSEMBLY

*DIAPHRAGM GASKET Gasket and diaphragm sequence may be reversed on some models. Head of rivet must touch inlet needle. *DIAPHRAGM

ATMOSPHERIC VENT HOLE *NON METALLIC ITEMS - CAN BE DAMAGED BY HARSH CARBURETOR CLEANERS

12

Proper installation of assembly is important. See appropriate chapter for procedures.

Hole must be clean. On models with primer bulb, vent hole is very small and is located off center or in the primer bulb.

EMISSIONIZED DIAPHRAGM CARBURETION Loosen screw until it just clears throttle lever, then turn screw in 1 IDLE SPEED ADJUSTMENT SCREW turn. Place detent reference mark to proper location. See chapter appropriate to specific carburetor.

CHOKE SHAFT AND LEVER Check shaft for binding. Position shutter opening towards inlet fitting CHOKE SHUTTER side of air horn.

THROTTLE SHAFT LEVER AND RETURN SPRING THROTTLE SHUTTER

HIGH SPEED AIR BLEED

IDLE, Remove welch plug and blow air INTERMEDIATE through air passages. AND AIR BLEED ORIFICES

TAMPER RESISTANT CAP (Pierce to Remove)

*INLET SEAT Remove and replace. GASKET Primer bulb models have a Teflon *INLET FITTING one way valve, in or behind the fitting. *INLET NEEDLE Proper installation of assembly is SEAT AND important. See appropriate chapter SPRING for procedures. ASSEMBLY

BLUE THREAD LOCK SEALANT APPLIED

*DIAPHRAGM Gasket and diaphragm sequence GASKET may be reversed on some models. Head of rivet must touch inlet needle. *DIAPHRAGM

FIXED IDLE RESTRICTER JET FIXED MAIN JET

MAIN NOZZLE WITH CHECK BALL

Hole must be clean. On models with ATMOSPHERIC VENT HOLE primer bulb, vent hole is very small and is located off center or in the primer bulb.

OUTBOARD CARBURETORS Carburetors on outboard applications use float type which have a separate idle speed fuel pickup tube pressed into the casting. The idle mixture screw is located on the top of the carburetor near the engine. This carburetor has been manufactured with 2 different types of inlet needle and seats. One has a hard needle with a synthetic rubber seat, the other has a nonreplaceable brass seat with a synthetic rubber tipped needle.

Outboard carburetors have a built-in fuel pump consisting of a fuel pump element which inflates and deflates with crankcase pulses which opens and closes two flap valves in the fuel pump, thereby pumping fuel from a remote tank to the carburetor float bowl. When replacing the fuel pump element, install with the slot opening at a 45 o angle as illustrated.

FUEL PUMP ELEMENT IDLE SPEED FUEL PICKUP

13

As the engine's piston, moves upward, a partial vacuum is created in the crankcase, which collapses the fuel pump element in the carburetor. On the outside of the element, suction opens the inlet flap drawing a supply of fuel from the tank and lines into the cavity created by the deflating pump element. Suction pulls the outlet flap closed, sealing the outlet port so that fuel isn’t pulled from the area of the inlet needle and seat.

IF CURLED OR FRAYED REPLACE

GASKET

On the downward stroke of the piston, crankcase pressure

INLET FLAP

FUEL PUMP ELEMENT DEFLATED INLET FLAP VALVE

COVER STRAINER

FUEL INLET

OUTLET FLAP

into the rod a complete 2 turns. Then position the extended end of the choke rod spring on the idle adjustment rod and align the spring with the choke rod holes in the bracket. Press the choke rod through the bracket and spring with the link attaching hole toward the carburetor side. Install the choke shaft link in the rod, then install the other end in the choke lever.

OUTLET FLAP VALVE

Install the control bracket to the carburetor, but do not tighten screw completely.

enlarges the pump element forcing fuel out of its cavity. This pressurized fuel acts against the outlet flap valve, opening it, allowing a head of pressurized fuel to be transmitted to the inlet needle and seat port. The inlet valve is pressed against the inlet port, sealing it so that pressurized fuel does not escape back into the fuel tank and lines.

Tighten the setscrew to secure the rod to the idle LINK

CHOKE ROD

THROTTLE LEVER POST

ROD STOP SPRING

The flap valves are located between the cover and FUEL PUMP ELEMENT INFLATED INLET FLAP VALVE

FUEL INLET

OUTLET FLAP VALVE

IDLE ADJUST NEEDLE AND SPRING

BRACKET IDLE ADJUST ROD

adjustment cable. The rod should turn about a half turn before contacting the extended end of the choke spring. It is important that the idle adjustment screw be one full turn from closed, and that the rod setscrew be down (6 o'clock position) when connecting the rod and coil. Tighten the control bracket screw. Pull the choke rod to assure that the choke shutter closes.

ABOUT 1/2 TURN

gasket. Make sure the flaps are in good condition and the strainer is not clogged or damaged. Replace as necessary. Make sure the cover is not warped; check by laying on a flat surface. If warped, replace. If not warped severely, it can be refaced using a hard surface and emery cloth. Notches on the carburetor body insure that the gasket, valve, and cover are positioned on the body correctly. When tightening screws, snug bottom screw, then top screw and torque to 6-8 in. lbs. OUTBOARD CONTROL PANEL. Install the idle adjustment rod into the bracket then turn the setscrew 14

6 O'CLOCK POSITION

FROM THE 6 O'CLOCK POSITION, THE ROD WILL TURN ABOUT 1/2 TURN EACH WAY BEFORE BEING STOPPED BY THE SPRING ROD

CARBURETOR ADJUSTMENTS Emission grade carburetors will have fixed main and idle circuits. The absence of adjustment screws indicate fixed jets with no adjustments necessary.

SERIES I

CARBURETOR ADJUSTMENTS IDLE SPEED ADJUSTMENT This screw is located on top of the carburetor and contacts the throttle. To pre-set the idle speed, back out the screw, then turn in until the screw just touches the throttle lever. Finally, turn the screw in one (1) turn. Once the engine is running and brought up to operating temperature (3-5 minutes), the final idle R.P.M. can be adjusted with the aid of a tachometer. FLOAT TYPE-FIXED MAIN, IDLE ADJUST Turn the mixture adjusting screw in (clockwise) finger tight, then one (1) turn out (counterclockwise). This setting is approximate and will be enough to allow the engine to start so that final carburetor adjustments can be made. Start the engine and allow it to warmup for approximately 5 minutes. Do not adjust the carburetor with the engine cold. NOTE: If the engine falters or stops after the choke lever is moved to the "OFF" position, open the mixture adjusting screw 1/4 turn counterclockwise and restart the engine.

IDLE MIXTURE SCREW

MAIN MIXTURE SCREW

SERIES III, IV

IDLE MIXTURE SCREW

MAIN MIXTURE SCREW

With the engine running, place the speed control in the "slow" position. Turn the mixture adjusting screw clockwise until the engine starts to falter, remember this location. Next turn the screw counterclockwise until the engine start to sputter or drops in R.P.M., remember this location. Now turn the screw clockwise until it is halfway between these two locations. This will be the optimum carburetor setting. DIAPHRAGM - SINGLE AND DUAL ADJUSTMENT Turn the mixture adjustment screw(s) clockwise finger tight, then one (1) turn counterclockwise. This setting will allow the engine to be started so that the carburetor can be fine tuned. Do not adjust the carburetor when the engine is cold.

DIAPHRAGM

"F" DESIGNATION

F-3 IDLE MIXTURE SCREW MAIN MIXTURE SCREW

Start the engine and let it warm-up for approximately 5 minutes. If the engine falters or stops after the choke lever is moved to the "OFF" position, turn the adjusting screw 1/4 turn counterclockwise and restart the engine. NOTE: On dual adjust, the first adjustment must be made with the main mixture screw. With the engine running, turn the mixture adjustment screw clockwise until the engine starts to falter, remember this location. Next turn the screw counterclockwise until the engine starts to sputter or drop in R.P.M., remember this location. Now turn the screw clockwise until it is halfway between these two locations. This will be the optimum carburetor setting. With dual adjust carburetor, repeat the above steps for the second (idle) mixture adjusting screw.

15

TROUBLESHOOTING CARBURETION POINTS TO CHECK FOR CARBURETOR MALFUNCTION TROUBLE

CORRECTIONS

Carburetor out of adjustment ............................... 3-4-11-12-13-15-20 Engine will not start ............................................. 1-2-3-4-5-6-8-9-10-11-12-14-15-16-17-19-21-24-25 Engine will not accelerate ................................... 2-3-4-5-11-12-19-24 Engine hunts (at idle or high speed) .................. 3-4-8-9-10-11-12-14-20-21-24-26-27 Engine will not idle ............................................... 3-4-8-9-10-11-12-13-14-18-20-21-22-24-25-26-27 Engine lacks power at high speed ..................... 2-3-4-6-8-10-11-12-15-18-19-20-21-24-25-26 Carburetor floods ................................................. 4-7-17-21-22-25-26 Carburetor leaks .................................................. 4-6-7-10-17-18-23-24-25 Engine overspeeds .............................................. 8-9-11-14-15-18-20 Idle speed is excessive ....................................... 8-9-13-14-15-18-20-25-26-27 Choke does not open fully .................................. 8-9-14-15 Engine starves for fuel at high speed (leans out) 1-3-4-5-6-10-11-15-16-17-18-19-21-25-26 Carburetor runs rich with main adjustment ......... 7-8-9-11-14-17-18-19-21-25-26 needle shut off Performance unsatisfactory after being serviced1-2-3-4-5-6-7-8-9-10-11-12-14-15-16-17-18-19-2021-24-25-26 1.

Open fuel shut off valve at fuel tank. Fill tank with fresh clean fuel.

16. Clean carburetor after removing all non-metallic parts that are serviceable. Trace all passages.

2.

Check ignition, spark plug and compression.

3.

Clean air cleaner service as required.

17. Check inlet needle and seat for condition and proper installation.

4.

Dirt or restriction in fuel system clean tank and fuel strainers, check for kinks or sharp bends.

5.

Check for stale fuel or water in fuel. Fill with fresh fuel/oil mixture of correct ratio.

6.

Examine fuel line and pick-up for sealing at fittings.

7.

Check and clean atmospheric vent holes.

8.

Examine throttle and choke shafts for binding or excessive play remove all dirt or paint, replace shaft.

9.

Examine throttle and choke return springs for operation.

10. Examine idle and main mixture adjustment screws and “O” rings for cracks or damage. 11. Adjust main mixture adjustment screw. Some models require finger tight adjustment. Check to see that it is the correct screw. 12. Adjust idle mixture adjustment screw. Check to see that it is the correct screw. 13. Adjust idle speed screw. 14. Check position of choke and throttle plates. 15. Adjust control cable or linkage to assure full choke and carburetor control. 16

18. Check sealing of welch plugs, cups, plugs and gaskets. 19. Check fuel pump operation pump element, inner and outer one way valves. 20. Adjust governor linkage. FLOAT CARBURETOR CHECKS 21. Adjust float setting. 22. Check float shaft for wear and float for leaks or dents. 23. Check seal for fuel drain or bowl gasket. 24. Is carburetor operating at excessive angle? CHECKS FOR DIAPHRAGM 25. Check diaphragm for cracks or distortion and check nylon check ball for function. 26. Check sequence of gasket and diaphragm for the particular carburetor being repaired. 27. Check spring tension on idle governor (if present).

STANDARD SERVICE CARBURETORS FUEL FITTING NOTE: MOST service carburetors are marked “SVC CARB NF” in the Price List. This means that the carburetor comes with NO FUEL FITTING. Use the parts manual to obtain the same fuel inlet fitting that was installed in the original carburetor. Install the fuel fitting in the new carburetor body in the same position as on the original carburetor. Support the carburetor body with a wood block to avoid damage to other parts. Use a bench vise or press to install the fitting squarely. Press it in until it bottoms out. NOTE: PRESS FUEL FITTING IN SQUARELY USING CAUTION SO THAT THE CARBURETOR BODY IS NOT DAMAGED. INLET FUEL FITTING To remove a leaking or damaged fuel inlet fitting, use a 1/4"(6 mm) bolt, 1/4" (6 mm) nut and 1/4" (6 mm) washer, along with a 1/2" (12 mm) nut. Use a pliers or vise to remove the plastic part of the inlet fitting. Tap the inside of the remaining metal portion of the fitting using a 1/4"- 20 (6 mm) tap. Place a 1/2" (12 mm) nut over the fuel fitting (it may be necessary to guide one side of the nut to seat it squarely to the carburetor). Next thread the 1/4" (6 mm) nut on the bolt until it contacts the shank, add the washer, and thread the bolt into the fitting until snug. Tighten the 1/4"-20 (6 mm) nut until the fitting is removed.

IDLE SPEED ADJUSTMENT SCREW Remove the screw assembly from the original carburetor and install it in the new carburetor. Turn it in until it contacts the throttle lever. Then an additional 1 turn for a static setting. FLOAT TYPE CARBURETOR CHOKE SHAFT IDLE CRACK SCREW AND SPRING SPRING WASHER FELT SEAL CHOKE STOP SPRING SHUTTER SCREW

FLOAT

SELF TAPPING SCREW LEVER SPRING WASHER FELT SEAL THROTTLE SHAFT

SHANK FUEL FITTING "O" RING SEAT AND CLIP INLET NEEDLE SPRING CLIP FLOAT SHAFT

FLOAT BOWL BOWL NUT WASHER HIGH SPEED BOWL NUT

DIAPHRAGM TYPE CARBURETOR CHOKE SHAFT NOTE: Never reuse choke or throttle shutter screws, always replace with new Tecumseh service screws part number 650506. Remove the choke shutter screw from the original carburetor and remove the choke shaft. Observe the position of the ends of the choke return spring if one is present. Also observe the position of the cut-out and/or holes in choke shutter. Some chokes turn clockwise and some turn counterclockwise, note the position of the choke shaft prior to removal from the old carburetor. If a choke stop spring is present on the new carburetor and is not used on the old carburetor, cut it off with a side cutter or pull it out using a pliers. Test the action of choke shaft to make sure it moves freely and easily and does not bind in either open or closed position. If binding occurs, loosen the shutter screw; reposition the shutter and tighten the screw. THROTTLE LEVER Remove the throttle lever and spring and file off the peened end of the throttle shaft until the lever can be removed. Install the throttle spring and lever on the new carburetor with the self-tapping screw furnished. If dust seals are furnished, install them under the return spring.

THROTTLE LEVER AND SHAFT

SPRING WASHER FELT SEAL THROTTLE SHUTTER SHUTTER SCREW IDLE ADJUSTMENT SCREW SEAL WASHER SPRING HIGH SPEED LOW SPEED ADJUSTMENT ADJUSTMENT SCREW SCREW

CHOKE LEVER AND SHAFT FUEL INLET

CHOKE SHUTTER SHUTTER SCREW

DIAPHRAGM DIAPHRAGM GASKET DIAPHRAGM COVER

PRIMER FITTING

DIAPHRAGM COVER SCREW

17

GOVERNORS AND LINKAGE AIR VANE GOVERNORS. All Tecumseh 2 cycle engines covered in this book are equipped with pneumatic (air vane) governors. The governor's function is to maintain a R.P.M. setting when engine loads are added or taken away. Air vane governors are controlled by the air velocity created by fins on the flywheel. Changes in the engine R.P.M. cause the air vane to move. The throttle is opened as the engine R.P.M. drops and is closed as the engine load is removed.

AIR VANE ASSEMBLY

OPERATION Engine R.P.M. changes cause an increase or decrease in the air velocity created by the fins on the flywheel. The air velocity exerts pressure on the air vane while a governor spring exerts pressure against the air velocity force. The air vane pivots on the engine flange or is attached to the throttle shaft of the carburetor. As an engine load is applied and the engine's R.P.M drop, the air velocity also drops, allowing the governor spring to pull open the throttle shaft and increase engine speed. LINKAGE INSTALLATION. The best method is to record the linkage attachment points prior to disassembly and reinstall the same way. Illustrations showing most governor and linkage hookups are pictured in this section. Select the diagram that resembles the engine you are servicing. R.P.M. settings may be found in microfiche catalog, card number 30. BEND TAB TO ADJUST RPM

AIR VANE

SLEEVE TABS

Rotate sleeve clockwise to increase R.P.M.; counterclockwise to decrease R.P.M. NOTE: The sleeve is serrated to rotate in a clockwise direction and must be raised using the sleeve tabs before it can be rotated counterclockwise. To disassemble, remove choke shutter with needlenose pliers; the vane assembly may then be removed from the carburetor.

18

HORIZONTAL FIXED SPEED PLASTIC AIR VANE GOVERNOR

ADJUST RPM BY LOOSENING SCREW AND SLIDING BRACKET Ó È INC DE R CR EA EA SE SE

HIGH SPEED RPM ADJUSTMENT

IDLE RPM ADJUSTMENT

IDLE MIXTURE

HORIZONTAL FIXED SPEED (ALUMINUM AIR VANE GOVERNOR)

ADJUST RPM BY LOOSENING SCREW AND SLIDING BRACKET Ó È INC DE R CR EA EA SE SE

THIS HOLE NOT PRESENT ON ALL MODELS SPRING

VERTICAL ENGINE VARIABLE SPEED-REMOTE CONTROL

SPRING GOVERNOR LINK

IDLE RPM ADJUSTMENT

IDLE MIXTURE THIS HOLE NOT PRESENT ON ALL MODELS

VERTICAL ENGINE FIXED SPEED-REMOTE CONTROL

HORIZONTAL FIXED SPEED

HIGH SPEED RPM ADJUSTMENT

IDLE RPM ADJUSTMENTS THIS HOLE NOT PRESENT ON ALL MODELS VERTICAL ENGINE VARIABLE SPEED MANUAL CONTROL

THIS HOLE NOT PRESENT ON ALL MODELS RPM ADJUSTMENT

SPRING

SPRING VERTICAL ENGINE FIXED SPEED

19

REWIND STARTERS, ELECTRIC STARTERS AND ALTERNATORS REWIND STARTERS GENERAL INFORMATION Rewind starters used on vertical shaft Tecumseh engines are top mount horizontal pull style or side mount vertical pull style. Horizontal shaft engines use side mounted starters which can be mounted to pull either vertically or horizontally. All rewind starters except the vertical pull style turn the engine over by engaging a dog(s) into the starter cup attached to the engine flywheel. The vertical pull starter engages the starter gear into the ring gear of the flywheel to turn the engine over. All starters are spring loaded to retract the dog(s) or starter gear when the engine speed exceeds the turning speed of the starter. OPERATION As the starter rope is pulled, the starter pulley rotates on the center pin. The starter dog(s) is pinned or pocketed in the pulley hub and extends outward when the pulley's rotation forces the starter dog(s) to contact the ears on the retainer. The retainer ears act as a ramp to fully extend the starter dog(s). The fully extended starter dog(s) locks in contact with notches in the starter cup. When the engine fires and the rotational speed of the starter cup exceeds the starter pulley, the starter dog(s) disengages from the starter cup. The starter dog spring(s) returns the starter dog(s) to the disengaged position. The recoil spring turns the starter pulley in the opposite direction, retracting the starter rope until the handle contacts the stop.

SERVICE Starter related problems will require the starter to be removed from the engine to diagnose the cause. Visually inspect the starter dog(s), starter cup, retainer, springs, rope, washers, and the starter pulley for wear or breakage. Use one of the following procedures that applies to your application, to disassemble, repair, and assemble the starter. Always consult the Tecumseh Master Parts Manual for the correct replacement parts. ROPE SERVICE Rope replacement should be done using the correct part number replacement rope or braided rope of the correct diameter and length. Consult the Tecumseh Master Parts Manual to obtain the correct part number, length, and size required. Use the following rope chart to convert a numbered rope to a fractional diameter for bulk rope use. # 4 1/2 rope = 9/64" (3.572 mm) diameter Part No. 730526 -100' (30.48 meters) spool # 5 rope

= 5/32" (3.964 mm) diameter Part No. 730514 - 100' (30.48 meters) spool

# 6 rope

= 3/16" (4.762 mm) diameter Part No. 730516 - 100' (30.48 meters) spool

Standard rope lengths 54" (16.5 meters) standard stamped steel starter

COMPONENTS STARTER HOUSING

HANDLE ROPE PULLEY AND REWIND SPRING ASSY.

DOG SPRING STARTER DOG

WASHER RETAINER BRAKE SPRING WASHER SPRING PIN

61" (18.6 meters) vertical pull - horizontal engagement type 65" (20 meters)

vertical pull - vertical engagement type

85" (26 meters)

extended handlebar rope start (compliance)

Check the old rope for the right length for the application. Some applications require longer lengths. The rope ends should be cauterized by burning with a match and wiping the rope end with a cloth while hot. Rope replacement can be done without the starter being disassembled on vertical pull starters that have "V" notches in the bracket. Use the following procedure for rope replacement. 1. Remove the starter assembly from the engine. 2. Turn the pulley until the staple in the pulley lines up with the "V" notch. Pry out the staple with a small screwdriver and remove the original rope.

20

3. Turn the pulley counterclockwise to fully wind the starter return spring until tight. Allow the pulley to unwind until the hole in the pulley lines up with the "V" notch. 4. Hold the pulley in this position and feed the new rope through the hole and tie a left-handed knot on the rope end. Make sure the rope and knot do not protrude from the knot cavity and bind the pulley rotation. LEFT-HAND KNOT

4. Remove the brake spring, spring retainer, washers, and pulley assembly (diag. 7, 8, 9 & 10) NOTE: The starter dogs face out on the stamped steel starter and the dogs face in on the stylized rewind starter. 5. All components in need of service should be replaced.

STARTER HOUSING

HANDLE ROPE PULLEY AND REWIND SPRING ASSY.

DOG SPRING STARTER DOG WASHER RETAINER

RETAINER REPLACEMENT 1. Remove the starter handle if the retainer is a complete circle design. Remove the staple and old retainer.

BRAKE SPRING WASHER SPRING PIN

2. Slide the rope retainer into the proper position and insert the staple using a pliers. 3. Install the starter handle and tie a left hand knot to secure the handle.

ONE PIECE ROPE RETAINER

STYLIZED REWIND STARTER Disassembly Procedure

1. After removing the rewind assembly from the engine blower housing, release the tension on the rewind spring. This can be done by removing the starter handle and carefully allowing the rope to unwind in the starter housing assembly. 2. Place a 1" (25 mm) deep well socket under the retainer. Set the rewind on a bench, supported on the socket. 3. Use a 5/16" (7.938 mm) or 1/4" (6.35 mm) (for stamped steel) roll pin punch to drive out the center pin. The stamped steel center pin is driven out from the top, inside the center hole. Move the punch around while driving the pin to help keep the pin straight. CAUTION: THIS REWIND SPRING IS NOT SECURED IN A CANISTER. PULLEY BOSSES HOLD THE REWIND SPRING AND COVER, AND CAN BE EASILY DISLODGED DURING HANDLING. 21

ASSEMBLY PROCEDURE NOTE: It is critical to support the starter on a deep well socket to prevent damage.

EYELET

HOLE IN PULLEY

1. Reverse the disassembly procedure. The starter dogs with the dog springs must snap back to the center of the pulley (disengaged position). When the rope is pulled, the tabs on the retainer must be positioned so that they will force the starter dogs to engage the starter cup. (diag. 7 & 8) 2. Always replace the center spring pin with a new one upon reassembly. Place the two new plastic washers between the center leg of the starter and the retainer. New plastic washers are provided with a new center spring pin. Discard the old plastic washer. 3. Place the rewind on a flat surface and drive the new center pin in until it is within 1/8" (3.175 mm) of the top of the starter. NOTE: DO NOT DRIVE THE CENTER PIN IN TOO FAR. The retainer will bend and the starter dogs will not engage the starter cup. On the stamped steel starter the center pin should be driven in until it contacts the shoulder in the starter body. 4. Wind the starter pulley counterclockwise four or five turns to pre-load the recoil spring, thread the rope through the starter housing eyelet and tie a temporary knot in the rope. Reattach the starter handle to the rope using a left-hand knot. Untie the temporary knot and allow the rope to recoil.

VERTICAL PULL STARTER HORIZONTAL ENGAGEMENT TYPE DISASSEMBLY PROCEDURE 1. Remove the handle and relieve the starter spring tension by allowing the rope to slip past the rope clip. 2. Remove the spring cover by carefully removing the two small screws. Carefully take out the spring. 3. Remove the center hub screw and the spring hub. 4. Lift off the gear and pulley assembly. Disassemble the pulley assembly by removing the snap ring and washer (diag. 13). 5. Remove the starter rope if necessary. Replace all worn or damaged parts.

HOUSING HANDLE ASSY.

HANDLE SPRING & KEEPER ASSY.

ROPE CLIP

ROPE

SCREW

ROPE PULLEY

BRAKE SPRING

RETAINER

DOG SPRING DOG RETAINER SCREW

STARTER DOG

22

R VE O C ING R SP EW B R HU SC NG I R SP EY LL PU G IN R R EA SP ER W G E H E AK AS CR BR T W P S S U A R SN TH D AN G N TI T N E U K O C M BRA

BRAKE SPRING

1. Insert the rope through the starter pulley.

STYLIZED REWIND STARTER WITH PLASTIC RETAINER

2. Assemble the gear, pulley, washer, and snap ring.

DISASSEMBLY PROCEDURE

3. Place a small amount of grease on the center shaft, place the gear and pulley into position making sure the brake spring loop is positioned over the metal tab on the bracket. The rope clip must fit tightly onto the bracket. The raised section fits into the hole in the bracket.

1. After removing the rewind assembly from the engine blower housing, remove the starter handle by first pulling a length of rope out using the handle, tying a temporary knot in the exposed rope, and either untying the knot in handle or prying out the staple.

Assembly Procedure

4. Install the hub and hub screw. Torque the hub screw to 45 - 55 in. lbs. (5 - 6 Nm). A loose hub screw will prevent the rope from retracting. 5. Install the return spring if necessary. A replacement spring is installed by placing the spring and its retainer over the top of the pulley and pushing the spring out of the retainer into the pulley's recessed area. 6. Install the spring cover and the cover screws. 7. Wind the rope onto the pulley by slipping it past the rope clip. When the rope is fully wound on the pulley, wind the pulley assembly two additional turns to put tension on the spring.

2. Untie the temporary knot and slowly allow the rope to fully retract into the starter housing and the recoil spring to fully unwind. 3. Remove the decal from the center of the starter housing. 4. Use a small Phillips screwdriver or similar tool to pry the retainer legs apart and lift out the retaining wedge. 5. Pinch the legs of the retainer together and pull on the head of the retainer to remove it from the housing. 6. Remove the pulley assembly from the recoil housing. 7. Repair or replace as necessary.

8. Mount the starter on the engine making sure the top of the starter gear teeth are no closer than 1/16" (1.59 mm) from the top of the flywheel ring gear teeth.

RETAINER WEDGE

STARTER HOUSING

LEFT-HAND KNOT

RECEPTACLE FOR RAISED SECTION

MOUNTING BRACKET TAB MUST FIT INTO SPRING LOOP

STARTER PULLEY SPRING & COVER

DOG SPRING STARTER DOG

RAISED SPOT ROPE CLIP

BRAKE

DOG RETAINER

ASSEMBLY 1. If replacing the starter rope, see Step 8. 2. Install a new recoil spring if necessary by pushing the new spring out of the holder into the pulley cavity while aligning the outside spring hook into the deep notch in the pulley. Push the spring cover in until seated. 3. Apply a small amount of lithium grease to the inner bore of the center shaft. 4. Replace or check that both starter dogs are in the pulley pockets and that the dog springs are hooked on the outer surface of the dog. 23

5. Pinch the two legs of the plastic retainer together and start into the center shaft hole. 6. Rotate the retainer so the two tabs on the bottom of the part fit between the dog and pulley hub (left side of the dog). Push the retainer in until the leg prongs pop out of the center shaft. 7. Turn the starter over and snap the locking tab between the retainer legs, replace the top decal. ROTATE COUNTERCLOCKWISE

NOTE: Refer to Service Bulletin 122 for metal locking tab. 8. Wind the starter pulley counterclockwise four or five turns to pre-load the recoil spring and thread the rope through the starter housing eyelet. Pull enough rope through to tie a temporary knot in the rope. Reattach the starter handle to the rope using a left-hand knot. Untie the temporary knot and allow the rope to recoil.

ASSEMBLY PROCEDURE

VERTICAL PULL STARTER, VERTICAL ENGAGEMENT TYPE

1. Feed the new rope through the hole and tie a lefthanded knot on the rope end. Make sure the rope and knot do not protrude from the knot cavity and bind the pulley rotation.

DISASSEMBLY PROCEDURE

STRUT

ORIGINAL INSTALLATION WITH STAPLE

1. Pull out enough rope to lock the rope in the "V" of the bracket.

INSTALL NEW ROPE BY TYING LEFT-HAND KNOT

2. Remove the handle if necessary by prying out the small staple in the handle with a screwdriver. 3. Place the starter bracket on the top of a deep well socket that is large enough to receive the head of the center pin. Use an arbor press to drive out the center pin. 4. Rotate the spring capsule strut until it is aligned with the legs of the brake spring. Insert a nail or pin no longer than 3/4" (19.05 mm) through the hole in the strut so it catches in the gear teeth. This will keep the capsule in the wound position. 5. Slip the sheave out of the bracket. CAUTION: DO NOT ATTEMPT TO REMOVE THE SPRING CAPSULE FROM THE SHEAVE ASSEMBLY UNLESS THE SPRING IS FULLY UNWOUND. 6. Squeeze and hold tightly by hand the spring capsule at the outer edge against the gear sheave. 7. Remove the retainer pin from the strut and slowly relieve the spring tension by allowing the spring capsule to rotate slowly under control, until completely unwound. The spring capsule can now be removed from the gear sheave.

REINSTALL LEFT-HANDED KNOT

LEFT-HAND KNOT

PRY STAPLE OUT TO REMOVE OLD ROPE

2. Wind the rope on the sheave assembly clockwise, viewing the gear from the gear side of the sheave. 3. Reinstall the brake spring, being careful not to spread the spring more than necessary. 4. Install the spring capsule, making sure the starter spring end hooks on the gear hub. 5. Wind the spring four full turns and align the brake spring legs with the strut as shown. Insert the pin in the strut. GEAR HUB STARTER SPRING END

SPRING HOOKED ON GEAR HUB

24

PIN

ROTATE SPRING 4 FULL TURNS

6. If the starter is equipped with a locking or delay pawl and spring, make sure these are in place before grasping the gear and spring capsule assembly and sliding it into the bracket. Make sure the legs of the brake spring are positioned in the slots of the bracket.

HANDLE INSERT

HANDLE STARTER ROPE

7. Feed the rope end under the rope guide and hook it into the "V" notch. Remove the pin and the strut will rotate clockwise against the bracket. 8. Insert the new center pin by pressing or driving the pin firmly in place. Reinstall the starter assembly on the engine. STARTER HANDLE ROPE

BRAKE

REWIND SPRING PULLEY RETURN SPRING STARTER DOG

HOUSING ASSY.

BRAKE

PULLEY BRAKE SPRING SPRING ASSY.

PAWL SPRING * CLIP * KEY*

STRUT PAWL

ROPE CLIP

LOCKING PAWL*

BRACKET

PIN

"V"ROPE WEDGE * USED ON SOME MODELS

GUIDE BRAKE ENDS THROUGH SLOT

TRUARC "E" CLIP

ASSEMBLY PROCEDURE. 1. Hook loop of spring into housing and wind in housing in a counterclockwise direction. The spring should have a light coating of grease on it. 2. Place pulley into housing. 3. Install dog spring and dog in starter pulley in the socket closest to the rope hole in pulley. 4. Replace brake spring, brake and install “E” clip. 5. To put tension on spring, wind pulley counterclockwise until tight, then allow to unwind until the hole in the pulley lines up with the eyelet in housing, then install rope and handle.

WHEN PIN IS REMOVED STRUT WILL ROTATE 45o CLOCKWISE

REWIND STARTER MOUNTED IN HOUSING DISASSEMBLY PROCEDURE. 1. Pull rope out to untie knot in rope and slowly release spring tension. 2. Remove “E” clip, brake, brake spring, starter dog and return spring. 3. Lift out pulley; rewind spring is located in the housing. Replace all worn or damaged parts.

25

ELECTRIC STARTERS The following electric starter illustrations will not be identical in configuration to the starter being serviced, but tests apply unless otherwise stated. Starters labeled CSA cannot be serviced, except for external components.

The following starter, number 590556, is a sealed UL and CSA approved starter, and the only component that can be serviced is the drive assembly.

END CAP BRUSHES BRUSH SPRINGS NUTS

BOLT

WASHER

THRUST WASHER

BRUSH CARD HOUSING

B

BRUSH SPRINGS

S RU

HC

AR

S DA

ENGAGING NUT

SY.

ANTI DRIFT SPRING SPRING RETAINER

GEAR

SPRING

FRICTION WASHER

DUST COVER

RETAINER RING

GEAR ARMATURE

LOCKNUT SPRING RETAINER ENGAGING NUT

DRIVE ASSEMBLY SERVICE. Pinion gear parts should be checked for damage or wear. If the gear sticks on the shaft, it should be washed in solvent to remove dirt and grease, then dried thoroughly. If damaged, replace with new parts. On units with the gear under the cap assembly, use the following procedure for disassembly:

RETAINER RING

To disassemble the drive assembly, use the following procedure: 1. Remove plastic dust cover. 2. Push down spring retainer and remove retainer ring. 3. Slide off spring retainer, anti-drift spring, gear, friction washer, and engaging nut. Inspect and replace as necessary. Use reverse procedure for assembly.

1. Remove retainer ring from armature shaft. 2. Remove the two nuts from the through bolts holding on the cap assembly. 3. Slide off the cap assembly. The engaging nut, gear, spring and spring retainer will remain in the cap assembly. 4. Remove, inspect, and replace as necessary. Use reverse procedure for assembly.

TORX ® E8 HEAD SCREW

The 590556 Electric Starter uses a mounting screw with a Torx® E-8 head. To torque this screw you must use a 670307 Torx ® E-8 socket.

26

STARTER CHECKING AND SERVICE. Remove nuts at both ends of the starter and take off rear end cap. CHECK BRUSHES. Before removing the armature, check brushes for wear. Make sure brushes are not worn to the point where the brush wire bottoms out in the slot of the brush holder. Brush springs must have enough strength to keep tension on the brushes and hold them against the commutator. If brushes need replacement, remove by unhooking the terminals or cutting the connections and then resoldering. If the brush card is warped from overheating, replace the card assembly.

TROUBLESHOOTING STARTERS. STARTER DOES NOT FUNCTION. Check for: 1. No current to the starter caused by faulty connections or blown circuit breaker. 2. Faulty safety switches, ignition, starter switch, or solenoid. 3. Engine locked up or parasitic load on engine. 4. Shorted, open, or grounded field coil. 5. Open, shorted, or bent armature. 6. Brushes sticking or damaged.

FIELD COIL CONNECTORS

7. Dirty or oily brushes or commutator. STARTER CRANKS ENGINE SLOWLY. Check for: 1. Parasitic load or “tight” engine. 2. Worn brushes or weak brush springs. 3. Dirty, oily, or worn commutator. 4. Worn bearings in cap assemblies. 5. Defective armature. CONNECTION POINTS OF POWER CORD LEADS

CHECK FIELD. Using a continuity light or ohmmeter, check the field by attaching one lead to each field coil connection. Continuity should exist between these two points. Check continuity between each field coil connection and the starter housing. No continuity should exist.

STARTER SPINS, ENGINE DOES NOT CRANK. Check for: 1. Pinion gear sticking on shaft. 2. Damaged pinion or flywheel ring gear.

ARMATURE CHECK. If the commutator bars are glazed or dirty they can be turned down on a lathe. While rotating, hold a strip of 00 sandpaper lightly on the commutator, and moving it back and forth. (Do not use emery cloth). Recut the grooves between the commutator bars to a depth equal to the width of the insulators.

Use a continuity tester to make certain no continuity exists between the commutator (copper) and the iron core of the armature, rotate armature and check out all commutator bars. The armature can be thoroughly checked with a growler if available.

27

ALTERNATORS Some engines are equipped with an alternator and regulator to supply current to power head lights, tail lights, etc. on recreation vehicles. Shown here is a typical wiring diagram.

(MOUNTED ON BLOWER HOUSING OR COVER PLATE) TYPE A

RED ­ LEAD

HEAD & TAIL LIGHT STOP LIGHT

MAGNETO GROUND

MAGNETO GROUND SWITCH

OHM METER

STOP LIGHT SWITCH

LIGHT SWITCH

VIEW FROM BOTTOM TAIL STOP LIGHT

HEAD LIGHT

CHECKING THE SYSTEM. At an idle speed (2600 R.P.M.) a slight dimming of the lights will be noticed, This is normal and should not be considered faulty. Before going into extensive checks, be sure to examine the more basic causes first, such as: 1. Make sure bulbs are good and the right ones are being used. Number 1157 for tail & stop light; 4416 or 4420 for head lights. 2. Corroded terminals. 3. Cracked wire insulation. 4. Broken wires. 5. Broken wires covered by insulation. 6. A wire grounding out the system. 7. Loose connections. 8. Make sure regulator has good ground. 9. Faulty Switch. Check the regulator for resistance. If regulator checks out and all bulbs and wiring are ok, replace alternator coils. Three types of regulators have been utilized. Use the ohm readings in the chart below for the type that you are servicing. Readings should be as follows:

28

(MOUNTED ON BLOWER HOUSING)

Type A

Type B

Type C

100 to 200

Over 50,000

100 to 200

Ohms

Ohms

Ohms

TYPE B

TYPE C

RED LEAD

VIEW FROM BOTTOM OHM METER

FLYWHEEL (INSIDE-EDGE) BRAKE SYSTEM Tecumseh’s brake systems provide two methods of meeting compliance standards which has become a Federal law as of June 30, 1982. There are two additional methods used by equipment manufacturers that also meet compliance standards, they are:

COMPONENTS

1. Use of the blade brake clutch in conjunction with either a top or side mounted recoil starter. The blade stops within three seconds after the operator lets go of the blade control bail at the operator position and the engine continues to run. Starter rope handle is on the engine.

The ignition kill switch is a plastic block with a wire extending out of it. The wire is attached to a terminal which is connected to the ignition kill wire. The brake lever contacts and grounds the wire of the switch when the engine / blade control is released, and the ignition module is grounded. This in turn kills the ignition.

2. Use of a recoil starter (top or side mounted) with the rope handle on the engine as opposed to within 24 inches from the operator position. This method is acceptable if the mower deck passes the 360 degree foot probe test. A specified foot probe must not contact the blade when applied completely around the entire blade housing. This alternative can be used with engine mounted brake systems and typical bail controls. The blade stops within three seconds after the operator lets go of the blade control bail at the operator position and the engine is stopped.

The interlock switch is a push button switch that is activated by the brake lever when the engine / blade control is actuated. If there is a starter switch used to start the engine, the interlock switch acts as a safety switch and will not allow the starter to crank unless the engine / blade control is depressed.

The Inside Edge system uses the following components: The brake lever and pad assembly consists of a steel lever with a brake pad bonded to the lever.

Where a two motion control is used the interlock switch is utilized as the starter switch. The Torsion Spring supplies the pressure to the brake lever and brake pad to stop the flywheel.

Tecumseh’s Flywheel (Inside-Edge) Brake System provides consumer safety by shutting down the engine and lawnmower blade within seconds after the operator releases the Engine/Blade control at the handle of the lawnmower.

The Control Cable transfers the motion of the engine / blade control to the brake system.

INSIDE EDGE SYSTEM

If the brake system fails to kill the ignition and stop the blade within 3 seconds the following service procedures should be followed.

In the stop position the brake pad is applied to the inside edge of the flywheel, at the same time the ignition system is grounded. In order to restart the engine, the brake control must be applied. This action pulls the brake pad away from the inside edge of the flywheel and opens the ignition kill switch. On electric start systems the starter is energized by an ignition switch or a two motion control. On non-electric start systems, the recoil starter rope must be pulled to start engine.

IGNITION SHORTED

IGNITION OPEN

SERVICE

Remove the flywheel as outlined in "IGNITION" section. NOTE: BEFORE THE FLYWHEEL IS REMOVED OR REPLACED, THE BRAKE PRESSURE ON THE FLYWHEEL MUST BE RE-LEVELED AS OUTLINED.

BRAKE APPLIED

BRAKE RELEASED

29

INSIDE EDGE To relieve the brake pressure on the flywheel, compress the spring by moving the lever toward the spark plug, when the hole in the lever aligns with the hole in the bracket, secure the lever with alignment tool 670298 then remove the flywheel (diag. 7). Remove the alignment tool. Release the spring tension by unhooking the short end of the spring from bracket with a pliers. Remove the “E” clip from the brake pad shaft. Slide the pad lever from the shaft and unhook the link. Inspect the brake pad for dirt, oil or grease contamination. If the pad is contaminated, or if there is less than .060" (1.524 mm) of brake pad material at the pad's thinnest point, replacement is necessary. The brake pad is bonded to the brake lever and must be replaced as an assembly. Rehook the link, install the brake lever and pad assembly, install the "E" clip, rehook the short end of the spring and continue to reassemble the brake system in the reverse order of disassembly.

To replace the interlock switch, carefully grind the heads off of the rivets that fasten the interlock switch to the brake bracket. Remove the rivets from the back side of brake bracket. Use the self-tapping screw supplied with the new switch to make threads in the bracket. Install the interlock switch onto the brake bracket in the proper position and secure the switch to the brake bracket with the machine screws supplied. Be careful not to overtighten the screws as switch breakage can occur.

SELF TAPPING SCREW MACHINE SCREWS

SHORT END OF SPRING ALIGN HOLES SWITCH LEVER

670298

IGNITION GROUND OUT TERMINAL Inspect the ignition kill switch grounding clip for proper alignment and contact with the brake arm. Insure that all electrical connections are clean and secure. GROUNDING CLIP

CONTROL CABLE

INSIDE EDGE If replacing the cable conduit screw with a screw other than a service part replacement, be certain that the screw length is not too long as to prevent free travel of the lever. Make sure the button on the starter interlock switch is completely depressed when the control is fully applied. The cable must provide enough travel so the brake will contact the flywheel. Some slack should exist in the cable adjustment to compensate for brake pad wear.

SCREW END MUST NOT BLOCK LEVER ACTION

GROUNDING CLIP POSITION

CABLE CLAMP SCREW

LINKAGE

"E" CLIP

BRAKE PAD

STARTER INTERLOCK SWITCH The engine / blade control must close the interlock switch before the starter can be engaged. To check the interlock switch, use an ohmmeter or continuity light to perform a continuity check. Continuity should exist between the two terminals when the interlock switch button is completely depressed. No continuity should exist when the button is released. If the switch fails replace the switch.

When installing a inside edge brake bracket assembly, be sure the slotted holes in the brake bracket are all the way down on the fasteners. This will properly align the brake bracket to the flywheel brake surface.

MOUNTING HOLES

Ô Ô MECHANISM FULL DOWN BEFORE SCREWS TORQUED

30

IGNITION IGNITION OPERATION

PATH OF MAGNET LINES OF FORCE

(PRE-1985 Production)

MAGNETO IGNITION. Tecumseh’s magneto ignition consists of a stator assembly made up of a coil, laminations, contact points, condenser, and a permanent magnet mounted in the flywheel of the engine.

PRIMARY WINDING

COIL: The coil consists of a primary and a secondary winding of wire. The primary is the low voltage (200300 volts) primary winding consists of about 150 turns of heavy gage wire next to the core. One end of the primary is connected to the insulated contact point and the other end is grounded to the stator body. The secondary winding consists of extremely fine wire with many turns (about 10,000) wrapped over the primary windings. One end connects to the spark plug and the other end is grounded to the stator body. The coil is used as a transformer to increase the primary voltage to a high voltage (10,000 - 20,000 volts) which jumps across the spark plug gap.

SECONDARY LEAD

PRIMARY LEAD

SECONDARY WINDING PRIMARY GROUND LEAD

PRIMARY WINDING

SECONDARY GROUND LEAD

FLYWHEEL ROTATION

MAGNET

POINTS CLOSED

As the flywheel continues to rotate, the North Pole approaches the last leg of the lamination stack. The magnetic field through the center leg reverses, producing a large change in the magnetic field and a high current in the primary windings of the coil. At this time, the contacts open and the primary current stops flowing. This change in current causes a voltage in the primary windings, which induces the high voltage in the secondary winding of the coil. The voltage is routed through the spark plug wire, to the spark plug, and then jumps the gap of the plug to ignite the fuel air mixture.

GROUND LEAD TERMINAL FOR PRIMARY AND SECONDARY

*The actual connection of the primary and secondary ground is normally made inside of *the coil, but it is shown above to illustrate the individual wires.

CONTACT POINTS. The contact points consist of an insulated movable point that connects to the coil primary lead and a stationary point that is grounded to the stator body which provides the return path for the primary circuit. CONDENSER. The condenser acts as an electrical shock absorber to prevent arcing between the contact points as they open. Arcing lowers the voltage at the spark plug, as well as burn and pit the contact points, thus shortening point life. OPERATION OF THE TECUMSEH MAGNETO IGNITION. As the flywheel turns, the magnets (mounted in the wheel) pass the coil mounted on the stator. As the magnet’s North Pole enters the area of the center leg of the stator, a magnetic field is concentrated through the laminations to the magnet’s South Pole. This causes a generation of current flow in the coil’s primary winding. The ignition points are closed.

POINTS OPEN

31

1985 to Present

SOLID STATE IGNITION. Tecumseh’s solid state capacitor discharge ignition (CDI) is an all electronic ignition system and is encapsulated in epoxy for protection against dirt and moisture. SOLID STATE IGNITION OPERATION. As the magnets in the flywheel rotate past the charge coil, electrical energy is produced in the module. This energy is transferred to a capacitor where it is stored until it is needed to fire the spark plug. The magnet continues rotating past a trigger coil where a low voltage signal is produced and closes an electronic switch (SCR). The energy which was stored in the capacitor is now transferred through the switch (SCR) to a transformer where the voltage is increased from 200 volts to 25,000 volts. This voltage is transferred by means of the high tension lead to the spark plug, where it arcs across the electrode of the spark plug and ignites the fuelair mixture.

32

IGNITION SERVICE SPARK PLUG SERVICE. Spark plugs should be cleaned and adjusted periodically. Check point gap with wire feeler gauge (.030" - .762 mm) and adjust gap. Replace if points are pitted and burned or the porcelain is cracked. Refer to Master Parts Manual or Micro-Fiche for correct replacement number. If spark plug fouls frequently, check for the following conditions: 1. 2. 3. 4. 5. 6. 7.

Carburetor set too rich. Choke not opening fully. Poor grade gasoline. Clogged exhaust system. Incorrect spark plug. Improper oil fuel ratio. Inconsistent spark. NOTE: Ensure cleaned spark plugs are free of all foreign material before installation.

FLYWHEEL REMOVAL AND SERVICE. To remove flywheel, use a strap wrench Part No. 670305 to hold the flywheel and remove the nut by turning it in the direction opposite of crankshaft rotation. STRAP WRENCH 670305

NOTE: A KNOCK-OFF TOOL IS NOT RECOMMENDED FOR ENGINES WITH A BALL BEARING ON THE MAGNETO END OF THE CRANKSHAFT. NOTE: If a knock-off tool is used, the pounding may cause the ball bearing to dislodge from the shroud base and force the lower thrust face of the crankshaft against the cylinder thrust face. TO CORRECT THIS CONDITION RAP SHARPLY WITH RAWHIDE MALLET ON THE P.T.O. END TO PROVIDE CLEARANCE BETWEEN CRANKSHAFT AND CYLINDER THRUST FACE. BALL BEARING

MUST HAVE CLEARANCE

If the flywheel is difficult to remove from the crankshaft because of rust, etc., the use of a propane torch can be helpful. Heat the area immediately outside of the crankshaft. The aluminum alloy in the flywheel should expand enough to break the seal away from the steel crankshaft.

NOTE: Do not attempt to remove flywheel using a jaw type pullers on the outer diameter of the flywheel or flywheel breakage will occur. On engines with cored holes (not tapped) use flywheel puller part No. 670306. FLYWHEEL PULLER 670306

FLYWHEEL MAGNETS. The magnets in the flywheel rarely lose their magnetic strength. If magnets are suspected to be faulty, place the flywheel upside down on a wooden surface. Hold a screwdriver by the extreme end of handle with the point down. Move the blade to within 3/4 inch of magnets. The magnets should attract the screwdriver blade against the magnet.

SCREWDRIVER LENGTH APPROXIMATELY 6" (15.24 cm)

3/4" (19

mm )

MAGNETS

33

FLYWHEEL KEYS. The flywheel key locates the flywheel to the crankshaft in the proper position. If a flywheel key is sheared, or partially sheared, the engine will not start or may be difficult to start.

FLYWHEEL TORQUE. Torque flywheel to the proper specification. See the tables in specification section for the proper torque setting. Loose lawn mower blades and adapters can contribute to sheared keys. REPLACING MAGNETO BREAKER POINTS. Remove the nut holding the electrical leads to the screw on the movable portion of the breaker points.

STEEL

CRANKSHAFT TIMING TABS

Remove the screw from the stationary breaker point and remove point set. Reinstall the new breaker point set into position and adjust the point gap according to the specifications. Points must be adjusted, when the rubbing block of the points is on the highest spot on the breaker cam.

ALUMINUM ALLOY

Clean points by putting lint-free paper between them and sliding it back and forth. Then open points and remove paper and any paper fiber remaining between the point set. Any oil, fingerprints or contamination will cause the points to burn prematurely.

GOLD SOLID STATE IGNITION

NOTE: Use the Tecumseh Master Parts Manual to determine correct key for the application. ADAPTER KEY TO FLYWHEEL ASSEMBLY. When an adapter is used, place the adapter with its raised key area in the flywheel keyway before putting the flywheel on the engine.

SLEEVE TO BE PRESSED IN FLUSH WITH HUB

FLYWHEEL SLEEVE. Some engines utilize a sleeve between the crankshaft and flywheel which acts as a flywheel key. If this sleeve becomes sheared or damaged, replace. The flywheel sleeve is pressed into the crankshaft opening in the flywheel, and should be flush or slightly below flush from the inside surface of flywheel before in stalling on crankshaft.

CONDENSER CHECK. Check condenser on a good quality tester, following the test equipment manufacturer’s instructions to check capacity and resistance. Replace condenser if condition is questionable. IGNITION COIL. Inspect the coil for cracks in insulation or other damage. Make sure electrical leads are intact, especially where they enter the coil. Check operation of the coil using an approved tester following the instructions furnished with the test unit. If laminations are distorted or damaged, replace. Some coils are permanently attached to the laminations and must be serviced as an assembly. IGNITION TIMING. Begin procedure by setting the point gap. This is done by rotating the crankshaft until the point arm is resting on the high side of the ignition cam. Set the point gap by loosening the screw on the movable point, and insert a feeler gauge per specification. Tighten the screw then recheck the gap. CRANKSHAFT

CAM

For engines equipped with brake system, a new key and flywheel are shown. Torque procedures are the same. NON-COMPLIANCE ENGINE

COMPLIANCE ENGINE

ARM

POINTS

FLYWHEEL SLEEVE

34

KEY

PIVOT

Install dial indicator (Part No. 670241) equipped with the correct tip on the extender leg. Use the small tip for engines with timing dimensions of between Top Dead Center and .050” (1.27 mm) BTDC . Use the large tip for engines with timing dimensions of between .051" (1.29 mm) BTDC to .150” (3.81 mm) BTDC. Loosen the screw on the side of the adaptor sleeve to allow the sleeve to be turned into the threads of the spark plug hole, not the entire dial indicator. This will ensure the proper location of the tip. Once the adapter sleeve is secured in the hole, tighten screw on sleeve adaptor to prevent the dial from moving up or down, which would give a false reading.

While watching the needle on the dial indicator, rotate the crankshaft counterclockwise (when looking at the magneto end of the crank) past the specified Before Top Dead Center (BTDC) dimension. Then rotate the crankshaft back clockwise to the proper dimension, this will take out any slack between the connecting rod and crankshaft assembly. (Using .080” (2.0 mm) BTDC dimension as an example.) DIAL AT .090” (2.29 mm)

DIAL AT .080” (2.0 mm)

T.D.C. B.T.D.C.

Find top dead center (TDC) by rotating the crankshaft clockwise (when looking at the magneto end of the crank) until the needle on the dial stops and reverses direction. Where the needle stops is TDC. Loosen the screw on the dial, and rotate the dial so that zero is lined-up with the needle at TDC. Tighten the screw on the dial to secure it in place.

DIAL AT 0

Next, disconnect the leads from the point terminal, and be sure to reinstall the securing nut & tighten it up. Connect one lead of a continuity light, or Ohmmeter to the point terminal and the other lead to a good ground. Loosen the two bolts holding down the stator and rotate the stator until the continuity light or Ohmmeter indicates a break in the circuit. At this point torque down the stator bolts and the timing procedure is completed.

DIAL SCREW

Before putting the dust cover back on the points box, clean the points by sliding lint free paper back and forth between the contacts. Manually, open the points when removing the paper to eliminate paper fibers from remaining between the contact points. LINT FREE PAPER

35

FIXED TIME SYSTEM (External Coil). This system has the contact points and condenser mounted under the flywheel with the laminations and coil mounted outside the flywheel. This system is identified by the square hole in the stator, the round configuration of the coil, and a stepped flywheel key.

SOLID STATE (CDI). This is an all electronic ignition system with the components sealed in a module and located outside the flywheel. A Solid State module can be identified by its square configuration, which will identify the need for the proper flywheel key or sleeve. SQUARE MODULE

Begin the timing procedure, torque down the stator bolts to secure the stator in place. Next rotate the crankshaft until the point arm is resting on the high side of the ignition cam. Set the point gap at to the proper specification by loosening the screw on the movable point, and inserting a feeler gauge between the contact points. Tighten the screw on the movable point and then recheck the point gap. Be sure to clean the contact points with lint free paper. Reinstall the proper flywheel key, flywheel, washer, and torque down the flywheel nut to specification. Reinstall the external coil, but do not tighten down the mounting screws.

FLYWHEEL SLEEVE

The proper air gap setting between the flywheel magnets and the laminations on both the fixed time and CDI systems is .0125'’. Place .0125'’ gauge, part No. 670297 between the magnets and laminations and torque down mounting screws to specification. Recheck gap setting to make certain there is proper clearance between the magnets and laminations. NOTE: Due to variations between pole shoes, air gap may vary from .005/.020'’ when flywheel is rotated. There is no further timing adjustment on external lamination systems. SQUARE MODULE

ROUND COIL STEPPED KEY .0125"

STEPPED END TOWARD ENGINE

FLYWHEEL SLEEVE

Timing this system consists of having the proper .0125" (.317 mm) air gap gauge, (Part No. 670297) between the magnets and laminations and torque down the mounting screws to specification. Remove air gap gauge and rotate flywheel to check for any possible striking points. If none are found, the air gap is set correctly and the timing procedure is completed.

.0125” (.317 mm)

36

OTHER IGNITION SYSTEMS. Ignition systems on engines with a non-adjustable stator, set the points per specification. If the coil is located under the flywheel, no other timing is required.

SET GAP PER SPECIFICATION

If engine has the coil and lamination outside of flywheel, set points per specification and set air gap between flywheel magnets and laminations to .005'’ to .008'’. Air gap gauge, part number 670216 which measures .0075'’ may be used. Use Loctite "242 Blue" on screws and torque down mounting screws to specification. Remove air gap gauge. MAGNETS

AIR GAP DIMENSION .005 .008

37

OUTBOARD TIMING OUTBOARD TIMING. (STANDARD IGNITION). Follow the step-by-step procedure outlined for timing outboard engines with Standard ignition magnetos (non-solid state).

Adjust ignition points to proper specification.

Apply a small amount of E.P. Lithium grease to the contact area of the friction screw. Do not turn the screw into the radius of the stator collar.

CONTACT AREA OF FRICTION SCREW

Clean points by sliding lint free paper back and forth between the contacts. Manually open points when removing paper to eliminate paper fiber from remaining between contacts.

Install the stator with operating handle pointed in the direction of the carburetor. Be sure the throttle post is NOT INSIDE the arc of the throttle actuating cam. Hold the throttle open when installing the stator.

Using a dial indicator, set the piston to the proper Before-Top-Dead-Center (BTDC) to the specified dimension.

T.D.C. B.T.D.C.

THROTTLE ACTUATING CAM THROTTLE POST CONTROL LEVER

Move the control lever to full retard, then move toward full advance while tightening the friction screw until the lever will not vibrate out of position when the engine is running and yet can be easily rotated when speed is adjusted.

Remove leads from point terminal, then reinstall and tighten the nut and washer. Attach a continuity device to the point terminal post and to a good ground on the engine as shown. LEADS REMOVED

FRICTION SCREW NUT AND WASHER

38

POINT TERMINAL POST

Move the stator counterclockwise, advancing the timing until the continuity reading breaks and reads zero. Tighten the stop bracket to secure the stator. Loosen the actuating cam locking screws just enough to allow adjustment of the cam. Move the actuating cam to open the throttle completely WITHOUT causing any binding with the throttle post.

OUTBOARD TIMING. (SOLID STATE). Follow these step-by-step procedures outlined for timing outboard engines with solid state magnetos. FRICTION SCREW

LOCKING SCREWS

GREASE CAM SURFACE

Using a dial indicator, set the piston to the specified Before-Top-Dead-Center (BTDC) dimension. STOP BRACKET

THROTTLE ACTUATING CAM THROTTLE POST

To coordinate the carburetor idle with ignition timing, rotate the crankshaft clockwise, to .003'’ After-TopDead-Center (ATDC).

T.D.C. B.T.D.C.

Rotate the control lever toward the idle position until continuity is obtained. Move the throttle actuating cam until it just touches the throttle post, without moving it. Tighten the screw slightly, then check the run position and idle position alternately to make sure the actuating cam is adjusted for both positions. Now tighten the screws.

Install timing tool 670238A on the crankshaft, be careful not to distort the keyway area. KEEP CONTINUITY LEADS ON TERMINAL POST AND GROUND

THROTTLE ACTUATING CAM

Without disturbing the BTDC piston position, move the control lever counterclockwise until the run trigger aligns with the timing tool (670238A) notch marked #1. Hold this position. NOTE: Some models do not have the “start” trigger. CONTROL LEVER

POS. -2 TOOL 670238A THIS SIDE UP POS. -1

SET CAM SO THAT IT JUST TOUCHES THE THROTTLE LEVER POST MOVE CONTROL LEVER UNTIL POINTS OPEN

"RUN" TRIGGER

GROUND SCREW

39

Adjust the stop bracket to prevent the control lever from moving any further counterclockwise. Then tighten the stop bracket screw. Loosen the actuating cam lock screw enough to allow adjustment of the cam. Position the cam so that it opens the throttle completely, making sure that the cam doesn’t cause binding on the post.

GROUND SCREW

When the correct position is attained, tighten the lock screw on the “high” end to hold the cam in place. THROTTLE ACTUATING CAM

THROTTLE ACTUATING CAM

LOCK SCREWS

GREASE CAM SURFACE

SCREW

STOP BRACKET

THROTTLE POST

CONTROL LEVER

Move the control lever to align the “RUN” trigger of the ignition unit with the number 2 position of the timing tool. Hold this position.

TOOL 670238A THIS SIDE UP 2

"START" TRIGGER

"RUN" TRIGGER

POS. -2

Adjust the actuating cam to touch the post without moving it. Tighten the lock screw to hold the cam in place.

40

LOCKING SCREWS

"RUN"

STOP BRACKET

THROTTLE POST CONTROL LEVER

Recheck to insure that the high speed point hasn’t changed or that binding will not occur. Readjust from the high speed point to the pickup point as necessary. When assured that the cam position is correct at the FULL RUN and IDLE positions, torque the lock screw to 10-15 in. lbs.

CYLINDERS & INTERNAL COMPONENTS PISTON & RING SERVICE

Before removing the piston, clean all carbon from the cylinder, making certain that the carbon ridge is removed from the top of the cylinder. This will prevent ring damage when removing the piston.

Most models have offset pistons. The pistons on these models have a “V” or "S" stamped on the piston head. When installing piston, this “V” mark must be in a 3 o’clock position when viewing the engine with the exhaust ports down.

Push the piston through the top of the cylinder using a wooden dowel on the inside of the piston so that the connecting rod and other parts will not be damaged.

"S" OR "V" MARK AT THE 3 O'CLOCK POSITION AND THE EXHAUST PORTS DOWN

Check the piston and cylinder for scoring or other damage. Check the piston rings for wear by inserting them into the cylinder to about 1/2 inch from the top of the cylinder. Check at various places to make sure that the gap between the ends of the ring do not exceed the dimensions indicated in the Table of Specifications. Bore wear can be checked by the same method, except, use a new ring to measure the end gap. FEELER GAUGE

INVERTED PISTON TO POSITION RING SQUARELY IN CYLINDER

PISTON RING

RING CENTERED IN RING TRAVEL AREA CHECK RING END GAP

Before installing the piston into the bore, put oil on the rings and piston, and stagger the ring end gaps. STAGGER RING END GAPS

41

CONNECTING ROD SERVICE Two cycle engines may be equipped with steel or aluminum connecting rods. Aluminum connecting rods use steel liners when needle bearings are utilized. The connecting rod bolts used are Torx ®, size E6. If torx sockets are not locally available, they can be purchased through your Tecumseh parts supplier under part number 670257. The connecting rod bolts should be tightened alternately and torqued to proper specification. All connecting rods have match marks on the connecting rod and cap. Make certain these match marks are aligned when assembling.

MATCH MARKS

MATCH MARKS

NEEDLE BEARINGS. Needle bearings may be single or split row. Split needles are to be installed with the blunt ends together and tapered ends outward.

SINGLE NEEDLE

TAPER

SPLIT NEEDLE

Service needles are supplied with a coating to hold the needles together and make installation easier. Remove the paper backing on the bearings and wrap uniformly around the crankshaft journal. Pull the connecting rod onto the crankshaft journal, place a few drops of oil onto the needle bearings and install rod cap. Torque bolts to specification.

42

CRANKSHAFT, BEARING AND OIL SEAL SERVICE Check if crankshaft is bent or otherwise damaged. Make certain keyways are not worn or damaged and flywheel taper is clean and in good condition. If taper or keyways are worn or damaged, replace crankshaft. Check oil seal contact surfaces on crankshaft for damage or scratches which would damage oil seal or cause leaks. On engines that are equipped with ball bearings, the crankshaft must be removed with the shroud base.

If a ball bearing engine appears to be tight, or if the flywheel was removed with the use of a knock-off tool, the ball bearing may be dislodged from shroud base, forcing the crankshaft lower thrust face against the cylinder thrust face, To correct this condition, rap sharply on the P.T.O. end of the crankshaft with rawhide mallet to provide the clearance between the crankshaft and cylinder thrust face. BALL BEARING

Before removing shroud base with crankshaft, disassemble rod cap from rod and remove the piston from the bore, then remove four (4) shroud base screws and tap shroud base so base and crankshaft can be removed together. To remove crankshaft and bearing from shroud base, use following procedure: Using a propane torch, heat the area of shroud base around the bearing area, until there is enough expansion to remove the crankshaft and bearing. HEAT AREA

HEAT AREA

MUST HAVE CLEARANCE

NEEDLE BEARINGS. Caged needle bearings can be removed and replaced by pressing them in and out of cylinder using an arbor press. NOTE: Always press against the lettered side of the bearing. If the needles fall out of the cage, they can be reinstalled using grease to hold them in position.

SHROUD BASE

To remove the bearing from crankshaft, remove retainer ring if so equipped, and use a bearing splitter to pull bearing. Before installing bearing on crankshaft, clean out the grooves on the crankshaft where bearing locates and put Loctite in the groove. Models with the retainer ring do not require Loctite. Using a sleeve over the crankshaft, press bearing into position with arbor press. Make certain crankshaft counter weight is supported and bearing is pressed on inner race only. RETAINER RING (some Models)

OIL SEALS. It is important on 2 cycle engines that oil seals are in good condition. A leaky seal will cause hard starting, erratic running, and possible damage to internal components due to a lean fuel-oil mixture caused by extra air getting into the crankcase. Engines could be equipped with either one piece oil seals or three pieces consisting of a seal, retainer and retainer ring; they are not interchangeable. ONE PIECE SEALS. An oil seal remover tool can be used for seal removal in some engines. In some cases it may be necessary to disassemble engine to remove the oil seals. Seal driver-protectors are available for most one piece oil seals. Select the proper tool from the tool list in Chapter 8. Place the oil seal over the driver protector, place over crankshaft, and drive into position using universal driver No. 670272. DRIVER (No. 670272)

BEARING SUPPORT COUNTERWEIGHT

OIL SEAL DRIVER-PROTECTOR

To reinstall crankshaft and ball bearing, heat shroud base to expand bearing seat and drop ball bearing into seat of base shroud. Allow to cool. On outboards only, install shroud base onto cylinder but before tightening screws, rotate shroud base fully clockwise. Tighten screws. 43

THREE PIECE SEALS. To remove seals, use a sharp object such as an ice pick to pry out the retainer spring, then remove the retainer and seal. In some cases it may be necessary to remove the crankshaft to remove the oil seals. RETAINER SPRING RETAINER SEAL

RING

RETAINER SEAL

OUTBOARD SEAL SERVICE. Oil seals on the powertake-off end of the crankshaft are installed in an inverted (upside down) position to keep water out of engine.

44

CYLINDERS, REEDS & COMPRESSION RELEASE

Cranking compression pressures bleed past reed valve, through a port, into the piston pin and out the exhaust port. REED OPEN

PISTON

Ô

Ô

If the reeds are serviceable, the smooth side of the reed must locate against the sealing surface. Service reeds have “smudge” marks on smooth side. If these marks are gone, feel for a rough edge and assemble away from sealing surface.

AUTOMATIC COMPRESSION RELEASE (SINGLE REED TYPE).

Ô

REED VALVES. Make sure reeds and sealing surfaces are free of dirt and foreign matter. Check reeds for seal against sealing surface of the adapter. Reeds should not bend away from sealing surface more than .010'’ (.254 mm).

Poor running or lack of power may be caused by a leaking reed or cover gasket.

Ô

GASKETS. Replace all gaskets in reassembly and make sure all sealing surfaces will not leak. A leaking gasket will cause erratic running, hard starting and could damage internal components by causing an imbalance of fuel-oil air mixture.

Replace both reeds If either is defective. When installing reeds be sure the colored side of the reed faces its seating surface. If in doubt, feel for a rough edge on the reed. The rough edge must be installed away from the seating surface. Assemble reed stop and hold down and tighten self-tapping screws.

Ô

CYLINDER & HEAD SERVICE. Check cylinder for bore damage or scoring. Check for broken or cracked fins, warped head or head mounting surface. If warped extensively, (more than .005"/.127 mm) replace. Always replace head gasket and torque to proper specification.

SINGLE REED

Ô

Ô

Ô

REED OPEN

EXHAUST PORT

Ô

PISTON PIN

TYPE II

As the engine starts and compression increases, the reed will be forced against the bottom port, sealing it and the engine will run under full compression. REED OPEN

PISTON

Cranking compression pressures bleed past reeds and into muffler. Once the engine is started, a high pressure build-up between the reeds forces the reeds against their seats stopping compression bleed off and allowing engine to run at full compression. CYLINDER REED

Ô

Ô

Ô

Ô

Ô

AUTOMATIC COMPRESSION RELEASE (DOUBLE REED TYPE).

SINGLE REED

EXHAUST PORT

REED CLOSED

PISTON PIN TYPE II

Install the reed cover (single reed type) with the small hole towards the spark plug.

COVER REED TYPE I

45

The piston used in the single reed compression release system has a cutout at the piston pin hole. The piston must be installed with the cut-out located on the side facing the compression release. CYLINDER EXHAUST PORTS. The muffler and cylinder exhaust ports should be cleaned after each seventyfive (75) to one hundred (100) hours of operation. It is recommended that the cylinder head be removed and carbon cleaned from the ports, cylinder head and top of piston. CAUTION: Do Not Scratch Metal Surfaces. With the cylinder head removed, remove any carbon deposits from the cylinder wall, head, and the top of the piston. Using a pointed 3/8'’ wooden dowel or similar tool, remove the carbon from the exhaust ports. Being sure to remove all loose carbon particles from the engine. NOTE: When cleaning the exhaust ports, check and clean the compression release passage.

46

TROUBLESHOOTING 2 CYCLE ENGINE TROUBLESHOOTING CHART Cause

Remedy and Reference

ENGINE FAILS TO START OR STARTS WITH DIFFICULTY No fuel in tank

Fill tank with clean, fresh fuel with correct oil ratio.

Fuel shut-off valve closed

Open valve.

Obstructed fuel line

Clean fuel screen and line. If necessary, remove and clean carburetor.

Tank cap vent obstructed

Open vent in fuel tank cap or replace cap.

Water in fuel

Drain tank. Clean carburetor and fuel lines. Dry spark plug points. Fill tank with clean, fresh fuel.

Engine overchoked

Close fuel shut-off and pull starter until engine starts. Reopen fuel shutoff for normal fuel flow immediately after engine starts.

Improper carburetor adjustment

Adjust carburetor.

Loose or defective magneto wiring

Check magneto wiring for shorts or grounds; repair if necessary.

Sheared or incorrect flywheel key or adapter sleeve

Replace with correct key or adapter sleeve.

Faulty Magneto

Check timing, point gap, and if necessary, overhaul magneto.

Spark plug fouled

Clean and regap spark plug.

Crankcase seals and/or gaskets leaking

Replace seals and/or gaskets.

Spark plug porcelain cracked

Replace spark plug.

Poor Compression

Overhaul engine.

Exhaust ports plugged

Clean exhaust ports

ENGINE KNOCKS Carbon in combustion chamber

Remove cylinder head or cylinder and clean carbon from head and piston.

Loose or worn connecting rod

Replace connecting rod.

Loose flywheel

Check flywheel key and keyway; replace parts if necessary. Tighten flywheel nut to proper torque.

Worn cylinder

Replace cylinder.

Improper magneto timing

Time magneto.

47

Cause

2 CYCLE ENGINE TROUBLESHOOTING CHART (Cont.) Remedy

ENGINE MISSES UNDER LOAD Spark plug fouled

Clean and regap spark plug.

Spark plug porcelain cracked

Replace spark plug.

Improper spark plug gap

Regap spark plug.

Pitted magneto breaker points

Clean and dress breaker points. Replace badly pitted breaker points.

Magneto breaker arm sluggish

Clean and lubricate breaker point arm.

Faulty condenser

Check condenser on a tester; replace if defective (see test instrument instructions and specifications).

Improper carburetor adjustment

Adjust carburetor.

Reed fouled or sluggish

Clean or replace reed.

Crankcase seal leak

Replace worn crankcase seals.

ENGINE LACKS POWER Choke partially closed

Open choke.

Blown head gasket

Replace head gasket.

Improper carburetor adjustment

Adjust carburetor.

Improper or partially sheared flywheel key or adapter sleeve.

Replace with new correct key or sleeve.

Magneto improperly timed

Time magneto.

Worn piston or rings

Replace piston or rings.

Air cleaner clogged

Clean air cleaner.

Reed fouled or sluggish

Clean or replace reed.

Improper amount of oil in fuel mixture

Drain tank; fill with correct mixture (See engine decal).

Carburetor improperly adjusted

Adjust carburetor.

Crankcase seals leaking

Replace worn crankcase seals

ENGINE OVERHEATS Engine improperly timed

Time engine.

Improper or partially sheared flywheel key or adapter sleeve.

Replace with new correct key or sleeve.

Air flow obstructed

Remove any obstructions from air passages in shrouds.

Cooling fins clogged

Clean cooling fins.

48

2 CYCLE ENGINE TROUBLESHOOTING CHART (Cont.) Cause

Remedy

ENGINE OVERHEATS (continued) Excessive load on engine

Check operation of associated equipment. Reduce excessive load.

Carbon in combustion chamber

Remove cylinder head or cylinder and clean carbon from head and piston.

Improper amount of oil in fuel mixture

Drain tank; fill with correct mixture.

ENGINE SURGES OR RUNS UNEVENLY Fuel tank cap vent hole clogged

Open vent hole.

Crankcase air leak

Inspect and replace gasket or seal.

Governor parts sticking or binding

Clean, and if necessary repair governor parts.

Carburetor throttle linkage or throttle shaft and/or butterfly binding or sticking

Clean, lubricate, or adjust linkage and deburr throttle shaft or butterfly.

ENGINE VIBRATES EXCESSIVELY Engine not securely mounted

Tighten loose mounting bolts (See equipment instructions).

Bent crankshaft

Replace crankshaft.

Driven equipment out of balance

Recheck driven equipment.

Piston installed incorrectly. Engines with wrist pin offset.

Install piston correctly.

49

SPECIFICATIONS

ENGINE TYPE NUMBER AND LETTER REFERENCE

Tecumseh has used two different methods of identifying 2 cycle engines.

The first method was used until the mid 1980's using the base model number with a type number. The type number was used to identify variations for the OEM's specific needs. The second method was put in place to standardize 2 cycle and 4 cycle engine identification. The type number has now become the specification number, which is preceded by the engine model. Example: AV520 Tecumseh type numbers are stamped into the blower housing, or are located on a nameplate or tag on the engine. Model and Specification numbers are either stamped into the blower housing, or located on a decal on the side of the blower housing. TYPE NO.

Column No.

Vertical Crankshaft Engines 638 thru 638-100 639 thru 639-13A 640-02 thru 640-06B 21 640-07 thru 640-21-A 640-23 641 thru 641-14 642-01,A 9A 642-02, A thru G 642-02E, F 642-03, A, B 642-04, A, B, C 642-05, A, B 642-06, A 642-07, A, B 642-07C 642-08 642-08A, B, C 642-09 thru 642-14 642-13 thru 14C 642-15 thru 642-23 642-24 thru 642-33 642-35 643-01, A, 03, A 643-03B, C 643-04, 05A 643-05B 643-13,14 643-14A, B, C 643-15 643-15A thru 643-32 643-32A 643-33 643-34 643-35,A,B 650 653-01 thru 653-05 653-07 thru 653-10 660-11 thru 660-38 660-39,A 660-40 661-01 thru 661-29 661-30 thru 661-45 662-02 662-623A 42

6 13 22 36 11 9A 9B 9A 9A 9A 9A 9A 9B 9B 9A 9A 9B 9B 9C 34 10A 10B 10A 10B 10A 10B 10A 10B 32 33 33 37 14 31 38 18 39 40 29 41 42

670-01 thru 670-109

8

Horizontal Crankshaft Engines 1398 thru 1399 1400 1401 thru 1401F 1401G, H

50

11 11 16 17

TYPE NO.

Column No.

Horizontal Crankshaft Engines 1401J 1402 and 1402B 1425 1430A 1432, A 1440, A, B, C, D 1442, A, B, 1444, A 1448 thru 1450 1450A, A, B, C, D, E 1450F 1454, A 1459 1460, A, B ,C, D, E, F 1462 1464, A, B 1465 1466, A 1471, A, B 1472, A, B, C 1473, A, B 1474 1475 thru 1476 1479 1482, A 1483 1484, A, B, C, D 1485 1486 1488, A, B, C, D 1489 thru 1490B 1491 1493, A 1494 and 1495A 1496 1497 1498 1499 1500 1501,A, B, C, D, E,F,G 1503, A, B, C, D 1506 1506B 1507 1508 1509 1510 1511 1512, A 1513 1515 thru 1516C 1517 1518

27 7 7 7 7 1 7 7 16 16 17 1 7 1 1 12 1 16 5 12 1 12 1 7 16 16 3 7 4 1 3 12 7 2 7 1 5 16 5 1 12 16 17 16 7 3 12 3 2 12 3 5 4

TYPE NO.

Column No.

Horizontal Crankshaft Engines 1519 thru 1521 1522 1523 1524 1525A 1527 1528,A,B 1529, A, B 1530, A, B 1531 1534A 1535B 1536 1537 1538 thru 1541A 1542 1543 thru 1546 1547 1549 1550A 1551 1552 1553 1554,A 1555 and 1556 1557 thru 1560 1561 1562 thru 1571 1572 1573 1574 thru 1577 1575 1578 1581 thru 1582A 1583 thru 1599A 1600 thru 1617 1618 thru 1619 1620 1622 thru 1623A 1624 thru 1642

MODEL AV520 AV600 AH600 HSK600 TVS600

1 12 1 2 16 3 1 3 1 3 17 3 12 1 12 5 1 3 3 15 16 20 16 3 16 15 19 23 2 3 23 24 25 23 26 28 43 30 42 35

PAGE NO. 61 61 61 61 61

SEARS CRAFTSMAN CROSS REFERENCE Craftsman Vertical Crankshaft Engines Craftsman No. 200.183112 200.183122 200.193132 200.193142 200.193152 200.193162 200.203112 200.203172 200.203182 200.203192 200.213112 200.213122 200.213132 200.223112 200.233112 200.243112 200.283012 200.2131128 200.2132228

Column No. 6 6 6 6 7 7 8 8 8 8 8 8 8 41 41 8 8 31 29

Craftsman Horizontal Crankshaft Engines Craftsman No. 200.503111 200.583111 200.593121 200.602112 200.613111 200.633111 200.643121 200.672102 200.682102 200.692112 200.692122 200.692132 200.701001 200.711001 200.731001 200.731011 143.943071 143.953071 143.973071 143.973091 143.983071 143.993071

Column No. 16 16 16 35 16 35 35 26 26 26 26 26 AH600-1665N HSK600-1665P HSK600-1686R HSK600-1687R HSK600-1687S HSK600-1700S HSK600-1705S HSK600-1700S HSK600-1708T HSK600-1712T

51

TABLE OF SPECIFICATIONS Reference Column

1

2

3

4

5

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

Bore

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

Stroke

1.250

31.75

1.410

35.814

1.410

35.814

1.410

35.814

1.410

35.814

Cu. In. Displacement (in3) (cc) Point Gap

4.40

72.1

4.80

78.7

4.80

78.7

4.80

78.7

4.80

78.7

.017

.432

.017

.432

.017

.432

.017

.432

.017

.432

Timing B.T.D.C.

.122

3.098

.100

2.54

.135

3.429

.100

2.54

.135

3.429

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston Ring End Gap

.007 .017

.178 .432

.007 .017

.178 .432

.006 .011

.15 .28

.006 .014

.15 .35

.006 .011

.15 .28

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0875 2.0885

53.023 53.048

2.0875 2.0885

53.023 53.048

2.0875 2.0885

53.023 53.048

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0975 .0985

1.664 1.689

.0655 .0665

1.664 1.689

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0955 .0965

1.638 1.664

.0645 .0655

1.638 1.664

Piston Ring Width

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0925 .0935

2.35 2.375

.0615 .0625

1.562 1.587

Piston Pin Diameter

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.3750 .3751

9.525 9.528

.4997 .4999

12.693 12.697

Crank Pin Journal Diameter

.5611 .5618

14.252 14.270

.5614 .5621

14.260 14.277

.5614 .5621

14.260 14.277

.6857 .6865

17.417 17.437

.5611 .5618

14.252 14.270

Crankshaft P.T.O. Side Main Brg. Dia.

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

Crankshaft Magneto Side Main Brg. Dia.

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

Crankshaft End Play

None

None

None

None

None

None

None

None

None

None

Piston Diameter (Top) Piston Ring Groove Width (Bot.)

52

TABLE OF SPECIFICATIONS Reference Column

6

7

8

9A

9B

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

Bore

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

Stroke

1.500

38.1

1.500

38.1

1.500

38.1

1.500

38.1

1.500

38.1

Cu. In. Displacement (in3) (cc)

5.20

85.2

5.20

85.2

5.20

85.2

5.20

85.2

5.20

85.2

Point Gap

.018

.457

.017

.432

.020

.508

.018

.457

.020

.508

Timing B.T.D.C.

.100

2.54

.185

4.699

.070

1.778

.100

2.54

.085

2.159

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston Ring End Gap

.006 .014

.153 .356

.007 .017

.178 .432

.006 .016

.153 .406

.007 .017

.178 .432

.006 .016

.153 .406

Piston Diameter

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

(Top) Piston Ring Groove Width

.0975 .0985

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

(Bot.)

.0955 .0965

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

Piston Ring Width

.0925 .0935

2.35 2.375

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

Piston Pin Diameter

.3750 .3751

9.525 9.528

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

Crank Pin Journal Diameter

.6857 .6865

17.417 17.437

.5611 .5618

14.252 14.270

.8442 .8450

21.443 21.463

.6857 .6865

17.417 17.437

.8442 .8450

21.443 21.463

Crankshaft P.T.O. Side Main Brg. Dia.

.8745 .8750

22.212 22.225

.6690 .6694

16.993 17.003

.9998 1.0003

25.349 25.408

.8745 .8750

22.212 22.225

.9998 1.0003

25.349 25.408

.7495 .7500

19.037 19.05

16.993 17.003

.6691 .6695

16.995 17.005

.7495 .7500

19.037 19.05

.7498 .7503

19.045 19.058

None

None

None

.003 .016

.076 .406

.003 .016

.076 .406

See Note 1

Crankshaft Magneto Side Main Brg. Dia.

See Note 2

Ball Bearing

.6690 .6694 See Note A

Crankshaft End Play

NOTE 1:

.003 .016

.076 .406

None

642-08, 14A, 14B B.T.D.C. = .110 642-16D, 19A, 20A, 21, 22 B.T.D.C. = .078

NOTE 2:

642-24, 26, 29 B.T.D.C. = .087

NOTE A:

Needle Bearing .7498 .7503

53

TABLE OF SPECIFICATIONS Reference Column

9C U.S.

10A U.S.

10B

2.093 2.094

Metric mm 53.162 53.188

U.S.

11

2.093 2.094

Metric mm 53.162 53.188

U.S.

12

Bore

2.093 2.094

Metric mm 53.162 53.188

2.093 2.094

Metric mm 53.162 53.188

U.S. 2.093 2.094

Metric mm 53.162 53.188

Stroke

1.500

38.1

1.750

44.45

1.750

44.45

1.750

44.45

1.410

35.814

Cu.In. Displacement (in3) (cc)

5.20

85.2

6.00

98.3

6.00

98.3

6.00

98.3

4.80

78.7

Point Gap

.020

.508

.018

.457

.020

.508

.018

.457

.017

.432

2.286

.087

2.21

.100

2.54

.135

3.429

See Note 4

Timing B.T.D.C.

.078

1.98

See Note 2

.090 See Note 3

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston RIng End Gap

.006 .016

.152 .406

.007 .017

.178 .432

.006 .016

.152 .406

.006 .014

.152 .356

.007 .017

.178 .432

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0873 2.0883

53.017 53.043

2.0870 2.0880

53.01 53.035

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0665 .0975

1.689 2.477

.0655 .0985

1.664 2.413

.0655 .0665

1.664 1.689

(Bot.)

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0955 .0965

2.426 2.451

.0645 .0655

1.638 1.664

Piston Ring Width

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0935

1.562 2.375

.0625 .0925

1.587 2.349

Piston Pin Diameter

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

Crank Pin Journal Diameter

.8442 .8450

21.443 21.463

.6857 .6865

12.417 17.437

.8442 .8450

21.443 21.463

.6857 .6865

17.417 17.437

.5614 .5621

14.26 14.277

Crankshaft P.T.O. Side Main Brg. Dia.

.9998 1.0003

25.395 25.408

.8745 .8750

22.212 22.225

.9998 1.0003

25.395 25.408

.8745 .8750

22.212 22.225

.6691 .6695

16.995 17.005

Crankshaft Magneto Side Main Brg. Dia.

.6691 .6695

16.995 17.005

.7495 .7500

19.037 19.05

.7498 .7503

19.045 19.058

.7495 .7500

10.037 19.05

.6691 .6695

16.995 17.005

Crankshaft End Play

None

None

.003 .016

.076 .406

.003 .016

.076 .406

.003 .016

.076 .406

None

None

Piston Diameter (Top) Piston Ring Groove Width

NOTE 2:

642-24, 26, 29 B.T.D.C. = .087

NOTE 3:

643-13 B.T.D.C. = .095

NOTE 4:

643-93A, 05A, 13, 14 = .020

54

TABLE OF SPECIFICATIONS Reference Column

13 U.S.

14 Metric mm

15

16

17

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

Bore

2.375 2.376

60.33 60.35

2.093 2.094

53.162 53.188

2.4375 2.4385

61.913 61.938

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

Stroke

1.680

42.672

1.500

38.1

1.750

44.45

1.500

38.1

1.500

38.1

Cu. In. Displacement (in3) (cc)

7.50

122.9

5.20

85.2

8.17

133.9

5.20

85.2

5.20

85.2

Point Gap

.020

.508

.018

.457

.018

.457

.017

.432

.017

.432

Timing B.T.D.C.

.095

2.413

.100

2.54

.100

2.54

.110

2.794

.110

2.794

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston Ring End Gap

.005 .013

.127 .330

.006 .014

.152 .356

.007 .017

.178 .432

.006 .016

.152 .406

.006 .016

.152 .406

2.3685 2.3695

60.16 60.185

2.0870 2.0880

53.01 53.035

2.4302 2.4312

61.727 61.753

2.0875 2.0885

53.023 53.048

2.0880 2.0890

53.035 53.061

.0655 .0665

1.664 1.664

.0975 .0985

1.664 1.689

.0655 .0665

1.664 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

(Bot.)

.0645 .0655

1.638 1.664

.0955 .0965

2.426 2.451

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

Piston Ring Width

.0615 .0625

1.562 1.587

.0615 .0935

1.562 2.375

.0625 .0925

1.587 2.35

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

Piston Pin Diameter

.4997 .4999

12.692 12.697

.3750 .3751

9.525 9.528

.4997 .4999

12.692 12.698

.3750 .3751

9.525 9.528

.4997 .4999

12.692 12.697

Crank Pin Journal Diameter

.6259 .6266

15.898 15.916

.6957 .6865

17.671 17.427

.6259 .6266

15.898 15.916

.6857 .6868

17.417 17.445

.6857 .6865

17.417 17.445

Crankshaft P.T.O. Side Main Brg. Dia.

.8650 .8850

21.971 22.479

.8745 .8750

22.12 22.225

.6691 .6695

16.995 17.001

.6691 .6695

16.995 17.001

.9998 1.0003

25.349 25.408

Crankshaft Magneto Side Main Brg. Dia.

.7495 .7503

19.037 19.058

.7495 .7500

19.037 19.058

.7495 .7500

19.037 19.058

.7495 .7500

19.037 19.058

.7495 .7500

19.037 19.058

Crankshaft End Play

None

None

.003 .016

.076 .406

None

None

None

None

None

None

Piston Diameter (Top) Piston Ring Groove Width

55

TABLE OF SPECIFICATIONS Reference Column

18 U.S.

19 Metric mm

20

21

22

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

Bore

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.4375 2.4385

61.913 61.938

2.437 2.438

61.900 61.925

Stroke

1.750

44.45

1.410

35.814

1.250

31.75

1.750

44.45

1.750

44.45

Cu. In. Displacement (in3) (cc)

6.02

98.7

4.80

78.7

4.40

72.1

8.17

133.9

8.17

133.9

Point Gap

.020

.508

.017

.432

.017

.432

.020

.508

.020

.508

Timing B.T.D.C.

.070

1.778

.100

2.54

.122

3.099

.118

2.997

.115

2.921

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston Ring End Gap

.006 .016

.152 .406

.007 .017

.178 .432

.007 .017

.178 .432

.007 .017

.178 .432

.007 .017

.178 .432

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.4302 2.4312

61.727 61.753

2.4302 2.4312

61.727 61.753

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

Piston Ring Width

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

Piston Pin Diameter

.4997 .4999

12.692 12.675

.4997 .4999

12.692 12.675

.4997 .4999

12.692 12.675

.4997 .4999

12.692 12.675

.4997 .4999

12.692 12.675

Crank Pin Journal Diameter

.8442 .8450

21.443 21.463

.5614 .5621

14.26 14.277

.5611 .5618

14.252 14.270

.6259 .6266

15.898 15.916

.6919 .6927

17.574 17.595

Crankshaft P.T.O. Side Main Brg. Dia.

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

Crankshaft Magneto Side Main Brg. Dia.

Ball Bearing

25.395 25.408

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.8745 .8750

22.212 22.225

.8748 .8753

22.223 22.233

None

None

None

None

None

None

None

None

None

Piston Diameter (Top) Piston Ring Groove Width (Bot.)

.9998 1.0003 See Note A

Crankshaft End Play

NOTE A:

None

Needle Bearing

.7498 .7503

* Does not apply to units with Solid State Ignition.

56

TABLE OF SPECIFICATIONS Reference Column

23

24

25

26

27

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

Bore

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

Stroke

.1500

38.1

1.410

35.814

.1410

35.814

1.500

38.1

1.500

38.1

Cu. In. Displacement (in3) (cc)

5.20

85.2

4.80

78.7

4.80

78.7

5.20

85.2

5.20

85.2

Point Gap

.017

.432

.017

.432

.020

.508

.020

.508

.017

.432

Timing B.T.D.C.

.110

2.794

.135

3.429

Fixed

Fixed

.062

1.575

.100

2.54

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston Ring End Gap

.006 .016

.152 .406

.007 .017

.178 .432

.007 .017

.178 .432

.006 .016

.152 .406

.006 .016

.152 .406

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0870 2.0880

53.01 53.035

2.0875 2.0885

53.01 53.035

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

Piston Ring Width

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

Piston Pin Diameter

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

Crank Pin Journal Diameter

.6919 .6927

17.574 17.595

.5614 .5621

14.26 14.277

.5614 .5621

14.26 14.277

.6919 .6927

17.574 17.595

.6922 .6927

17.582 17.595

Crankshaft P.T.O. Side Main Brg. Dia.

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.6691 .6695

16.995 17.005

.7498 .7503

19.045 19.058

.6691 .6695

16.995 17.005

Crankshaft Magneto Side Main Brg. Dia.

.7498 .7503

19.045 19.058

.6691 .6695

17.551 17.005

.6691 .6695

17.551 17.005

.6691 .6695

17.551 17.005

.7498 .7503

19.045 19.058

Crankshaft End Play

None

None

None

None

None

None

None

None

.003 .016

.076 .406

Piston Diameter (Top) Piston Ring Groove Width (Bot.)

57

TABLE OF SPECIFICATIONS Reference Column

28

29

30

31

32

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

Bore

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

Stroke

1.500

38.1

1.746

44.348

1.746

44.348

1.500

38.1

1.746

44.348

Cu. In. Displacement (in3) (cc)

5.20

85.2

6.0

98.3

6.0

98.3

5.20

85.2

6.0

98.3

Point Gap

.020

.508

.020*

.508

.020

.508

.020

.508

.020

.508

Ext. Ignition

Ext. Ignition

Ext. Ignition

Ext. Ignition

.052

1.321

Ext. Igniton

Ext. Ignition

.088

2.235

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston Ring End Gap

.006 .016

.152 .152

.007 .017

.178 .432

.006 .016

.152 .152

.006 .016

.152 .152

.006 .016

.152 .152

2.0875 2.0885

53.023 53.048

2.0865 2.0875

52.997 53.023

2.0875 2.0885

53.023 53.048

2.0865 2.0875

52.997 53.028

2.0865 2.0875

52.997 53.023

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

Piston Ring Width

.0615 .06251

1.652 .587

.0615 .0625

1.652 1.587

.0615 .0625

1.652 1.587

.0615 .0625

1.652 1.587

.0615 .0625

1.652 1.587

Piston Pin Diameter

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

Crank Pin Journal Diameter

.6922 .6927

17.582 17.595

.8113 .8118

20.607 20.620

.8113 .8118

20.607 20.620

.8113 .8118

20.607 20.620

.8445 .8450

21.450 21.463

Crankshaft P.T.O. Side Main Brg. Dia.

.7498 .7503

19.045 19.058

.9998 1.0003

25.395 25.408

.7498 .7503

19.045 19.058

.9998 1.0003

25.395 25.408

.9998 1.0003

25.395 25.408

Crankshaft Magneto Side Main Brg. Dia.

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.7498 .7503

17.005 17.015

.6695 .6699

17.005 17.015

Crankshaft End Play

None

None

None

None

None

None

None

None

.003 .016

.076 .406

Timing B.T.D.C.

Piston Diameter (Top) Piston Ring Groove Width (Bot.)

*Does not apply to units with Solid State Ignition.

58

TABLE OF SPECIFICATIONS Reference Column

33

34

35

36

37

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

Bore

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.437 2.438

61.90 66.925

2.093 2.094

53.162 53.188

Stroke

1.746

44.348

1.746

44.348

1.500

38.1

1.746

44.348

1.750

44.45

Cu. In. Displacement (in3) (cc)

6.0

98.3

6.0

98.3

5.20

85.2

6.0

98.3

6.0

98.3

Point Gap

.020

.508

.020

.508

*.020

.508

.020

.508

.020

.508

Timing B.T.D.C.

.073

1.854

.078

1.854

Ext. Ignition

Ext. Ignition

.112

2.845

.088

2.235

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston Ring End Gap

.006 .016

.152 .406

.006 .016

.152 .406

.006 .016

.152 .406

.007 .017

.178 .432

.006 .016

.152 .406

2.0865 2.0875

52.997 53.023

2.0865 2.0875

52.997 53.023

2.0882 2.0887

53.04 53.05

2.4307 2.4317

61.74 61.765

2.0880 2.0885

53.035 53.049

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

Piston Ring Width

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

Piston Pin Diameter

.4997 .4999

12.692 12.698

.4997 .4999

12.692 12.698

.4997 .4999

12.692 12.698

.4997 .4999

12.692 12.698

.4997 .4999

12.692 12.698

Crank Pin Journal Diameter

.8113 .8118

20.607 20.620

.8445 .8450

21.450 21.463

.8113 .8118

20.607 20.620

.6922 .6927

17.582 17.595

.8445 .8450

21.450 21.463

Crankshaft P.T.O. Side Main Brg. Dia.

.9998 1.0003

25.395 25.408

.9993 1.0003

25.295 25.408

.7498 .7503

19.045 19.058

.6695 .6699

17.005 17.015

.9998 1.0003

25.395 25.408

Crankshaft Magneto Side Main Brg. Dia.

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.8748 .8753

22.22 22.233

.6695 .6699

17.005 17.015

Crankshaft End Play

.003 .016

.076 .406

.003 .016

.076 .406

None

None

None

None

.003 .016

.076 .406

Piston Diameter (Top) Piston Ring Groove Width (Bot.)

59

TABLE OF SPECIFICATIONS Reference Column

38

39

40

41

42

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

U.S.

Metric mm

Bore

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

2.093 2.094

53.162 53.188

Stroke

1.828

46.431

1.500

38.1

1.828

46.431

1.746

44.348

1.500

38.1

6.0

98.3

5.20

85.2

6.0

98.3

6.0

98.3

5.20

85.2

.020

.508

.020

.508

*

.020

.508

Cu. In. Displacement (in3) (cc) Point Gap Timing B.T.D.C.

* Ext. Ignition

Ext. Ignition

.088

2.235

.070

1.778

Ext. Ignition

Ext. Ignition

Ext. Ignition

Ext. Ignition

Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston Ring End Gap

.006 .016

.152 .406

.006 .016

.152 .406

.006 .016

.152 .406

.006 .016

.152 .406

.006 .016

.152 .406

2.0880 2.0885

53.035 53.049

2.0880 2.0885

53.035 53.049

2.0880 2.0885

53.035 53.049

2.0880 2.0885

53.035 53.049

2.0880 2.0885

53.035 53.049

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

.0645 .0655

1.638 1.664

Piston Ring Width

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

Piston Pin Diameter

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

.4997 .4999

12.692 12.697

Crank Pin Journal Diameter

.8113 .8118

20.607 20.620

.8113 .8118

20.607 20.620

.8445 .8450

21.450 21.463

.8113 .8118

20.607 20.620

.8113 .8118

20.607 20.620

Crankshaft P.T.O. Side Main Brg. Dia.

.9998 1.0003

25.395 25.408

.9998 1.0003

25.395 25.408

.9998 1.0003

25.395 25.408

.9998 1.0003

25.395 25.408

.7498 .7503

19.045 19.058

Crankshaft Magneto Side Main Brg. Dia.

.7498 .7503

19.045 19.058

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

Crankshaft End Play

None

None

None

None

None

None

None

None

None

None

Piston Diameter (Top) Piston Ring Groove Width (Bot.)

* Does not apply to units with Solid State Ignition.

60

TABLE OF SPECIFICATIONS Specification

AV520 U.S. Metric mm

AV600 U.S. Metric mm

AH600 U.S. Metric mm

HSK600 U.S. Metric mm

TVS600 U.S. Metric mm

53.162 53.188

2.09

53

2.09

53

2.09

53

2.09

53

2.09

53

1.5

38.1

1.5

38

1.75

44

2.09

44

1.75

44

1.75

44

Cu. In. Displacement (in3) (cc)

5.20

85.2

5.2

85 cc

6.0

98 cc

6.0

98 cc

6.0

98 cc

6.0

98 cc

Point Gap

.020

.508

Ext. Ignition

Ext. Ignition .0125

.3175

.0125

.3175

.0125

.3175

.0125

.3175

.0125

.3175

Bore

Stroke

Timing B.T.D.C.

43 U.S.

Metric mm

2.093 2.094

Ignition Module Air Gap Spark Plug Gap

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

.030

.762

Piston Ring End Gap

.006 .016

.152 .406

.006 .016

.152 .406

.006 .016

.152 .406

.006 .016

.152 .406

.006 .016

.152 .406

.006 .016

.152 .406

Piston Diameter

2.0880 2.0885

53.035 2.0877 53.049 2.0882

53.03 53.04

2.0877 2.0882

53.03 53.04

2.0877 2.0882

53.03 53.04

2.0877 2.0882

53.03 53.04

2.0877 2.0882

53.03 53.04

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0645 .0655

1.638 1.664

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

.0655 .0665

1.664 1.689

Piston Ring Width

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

.0615 .0625

1.562 1.587

Piston Pin Diameter

.4997 .4999

12.692 12.697

.5005 .5007

12.713 12.718

.5005 .5007

12.713 12.718

.5005 .5007

12.713 12.718

.5005 .5007

12.713 12.718

.5005 .5007

12.713 12.718

Crank Pin Journal Diameter

.6922 .6927

17.582 17.595

.8445 .8450

21.450 21.463

.8445 .8450

21.450 21.463

.8445 .8450

21.450 21.463

.8445 .8450

21.450 21.463

.8445 .8450

21.450 21.463

Crankshaft P.T.O. Side Main Brg. Dia.

.7498 .7503

19.045 .9998 25.395 19.058 1.0003 25.408

.9998 1.0003

25.395 25.408

.7498 .7503

19.045 19.058

.7498 .7503

19.045 .9998 25.395 19.058 1.0003 25.408

Crankshaft Magneto Side Main Brg. Dia.

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

.6695 .6699

17.005 17.015

Crankshaft End Play

None

None

.003 .016

.076 .406

.003 .016

.076 .406

.003 .016

.076 .406

.003 .016

.076 .406

.003 .016

.076 .406

(Top) Piston Ring Groove Width (Bot.)

61

TABLE OF TORQUE LIMITS INCH POUNDS

NEWTON METERS

80 - 100

9 - 11

Flywheel Nut Connecting Rod Screws Aluminum Rods Steel Rods

264 - 324

30 - 37

40 - 50 70 - 80

4.5 - 5.5 8-9

Spark Plug

192 - 264

21.5 - 30

Fuel Tank Screws

12 - 20

1.5 - 2

Blower Housing Mounting Screws

80 - 100

9-11

Muffler Mounting Screws

80 - 100

9 - 11

Muffler Cover (Snowthrowers)

20 - 30

2 - 3.5

Stator to Base (Except Outboards)

80 - 100

9 - 11

External Screws to Laminations

30 - 40

3.5 - 4.5

Point Screw

15 - 25

1.5 - 3

Air Filter or Carburetor Baffle (Metal)

30 - 40

3.5 - 4.5

Air Filter (Plastic)

18 - 25

2-3

Carburetor Mounting Nuts

60 - 75

7- 8.5

Reed Plate, Cover Plate

35 - 45

4-5

Reed Hold down

15 - 25

1.5- 3

Compression Release Cover

30 - 40

3.5 - 4.5

Shroud Base to Block

80 - 100

9 - 11

Starter Mounting Screws (Metal)

50 - 70

5.5- 8

Starter Mounting Screws (Plastic)

30 - 40

3.5 - 4.5

Electric Starter Mounting Screws

65 - 85

7.5 - 9.5

Stop Lever to Head

80 - 100

9 - 11

Speed Control to Shroud Base

30 - 40

3.5 - 4.5

Compliance Brake Bracket to Cylinder

60 - 80

7-9

Compliance Brake Bracket to Base

35 - 50

4 - 5.5

Cylinder

"Torque specifications listed on this page should not be confused with the torque value observed on engines which have been run. Torque relaxation occurs on all engines from thermal expansion and contraction. The torque specifications take relaxation into account so a sufficient clamping force exists after an engine has been run.”

62

EDUCATIONAL MATERIALS AND TOOLS AVAILABLE TECHNICIAN'S HANDBOOKS 692508 Covers the diagnosis and repair of Tecumseh 2-cycle engines. Except the TC Engine and TVS840. 692509 Covers the diagnosis and repair of the Tecumseh 4-cycle light/medium frame engines. 691462A Covers the diagnosis and repair of Tecumseh 4-cycle large frame engines. 691218 Covers the diagnosis and repair of Peerless® power train components. 694782 Contains technical information for the repair of the TC series, 2-cycle engines. 694988 Contains diagnosis and technical information for the repair of TVS840, HSK/HXL845/850, 2-cycle engines. 695244A Covers the diagnosis and repair of the OVRM/OVM/ OHH/OHM/OHV 4-cycle overhead valve engines. 695578 Covers the diagnosis and repair of the Vector Series, 4-cycle engines.

695185 Electrical Troubleshooting. This video training program will assist the small engine technician in the proper procedures for troubleshooting electrical systems on outdoor power equipment.

AVAILABLE FOREIGN TECHNICIAN'S HANDBOOKS

695907 This booklet is designed as a quick reference to carburetion problems and related repair procedures.

694732 Spanish This manual covers the following models: VH80, VH100, HH80, HH100, HH120, OH120-180 Model numbers are located on the engine shroud. 695555 Spanish Covers the diagnosis and repair of the Tecumseh 4-cycle light/medium frame engines. 695657 German Covers the diagnosis and repair of the Tecumseh 4-cycle light/medium frame engines. 695562 French Covers the diagnosis and repair of the Tecumseh 4-cycle light/medium frame engines. VIDEO PROGRAMS 695015 Carburetor Troubleshooting. Covers identification of carburetors used on Tecumseh engines and how to troubleshoot and repair them. VHS only. 695059 Understanding Tecumseh Ignition Systems. A basic program designed to give the small engine technician first hand knowledge of Tecumseh ignition systems so the technician can understand the system and perform repairs to it. VHS only. 695148 Teardown and reassembly of the 900 series transaxles. This video will show a complete step-by-step procedure for teardown and reassembly of the 900, 910 and 920 series transaxles.

695285 An in-depth look at the 800 series transaxles. Detailing the teardown and reassembly procedures for the 800, 801 and 820 transaxles. SPECIALTY / TROUBLESHOOTING BOOKLETS INSTRUCTIONAL GUIDE 692738 Assists in the use and understanding of the Tecumseh Master Parts Manual. Illustrates time saving features incorporated into the manual. Explains new carburetor parts breakdown format. 4-CYCLE ENGINE FAILURE ANALYSIS 695590 This booklet is designed as a tool for the average technician to correctly assess the cause of failure. CARBURETOR TROUBLESHOOTING BOOKLET

IGNITION SYSTEMS TROUBLESHOOTING BOOKLET 694903 This booklet contains information on the identification, possible problems and related repair procedures of Tecumseh Ignition Systems. SPECIAL TOOLS BOOKLET 694862 This booklet depicts all specialty tools offered by Tecumseh which can be used on 2 and 4 cycle engines and Peerless units. QUICK REFERENCE CHART BOOKLET 695933 This booklet contains the quick reference information found on Tecumseh wall charts. This booklet is designed to be used as a work bench quick reference guide when servicing Tecumseh engines and motion drive systems. TESTER BOOKLETS 694529 Test procedures for Tecumseh electrical components using Graham-Lee Tester 31-SM or 31-SMX-H. 694530 Test procedures for Tecumseh electrical components using Merco-O-Tronic Tester 9800. (Tests are similar for 98, 98A and 79.) 63

64

OIL SEAL DRIVER - PROTECTOR

DIAL INDICATOR

BALL BEARING DRIVER

No. 670258 PISTON RING EXPANDER

Extra Tips: Large Head No. 670250 Thin Head No. 670249 Leg and Screw No. 670296

No. 670241 - Dial Indicator. OIL SEAL REMOVER

No. 670117 - Piston ring expander TAPER GAP GAUGE

No. 670286. Used on P.T.O. end of single cylinder outboards with one piece oil seals. Includes tool No. 670285 and center screw. No. 670291. Used on magneto end of all two cycle engines with one piece oil seals and P.T.O. end of 1600 series. Includes tool No. 670280 and center screw. No. 670257. Used on 2 cycle connecting rod screws.

No. 670256 - Taper Gap Gauge VIBRATION TACHOMETER

No. 670307. Used on 590556 electric starter mounting screws. TORX ® E-6 SOCKET No. 670257

TORX ® E-8 SOCKET No. 670307

No. 670156 - Vibration tachometer.

No. 670298 - Aligning Pin 65

TECUMSEH T E C H N I C I A N ' S

H A N D B O O K

This manual covers engine models: ECV100 - 120, H22 - 80, HH40 - 70, HHM80, HM70 - 100, HMSK70 - 110, HMXL70, HS40 - 50, HSK30 - 70, HSSK40 - 50, HT30 - 35, HXL35, LAV30 - 50, LEV80 - 120, TNT100 - 120, TVM125 - 220, TVXL170 - 220, TVS75 - 120, TVXL105 - 115, V40 - 80, VH40 - 70, V60 - 70, VM70 - 100 Model numbers are located on the engine shroud.

3 TO 11 HP 4-CYCLE L-HEAD ENGINES

ENGINES & TRANSMISSIONS

CONTENTS CHAPTER 1 GENERAL INFORMATION ...................................................................................................... 1 ENGINE IDENTIFICATION ............................................................................................................................ 1 INTERPRETATION OF MODEL NUMBER .................................................................................................... 1 SHORT BLOCKS ........................................................................................................................................... 2 FUEL .............................................................................................................................................................. 2 ENGINE OIL ................................................................................................................................................... 3 TUNE-UP PROCEDURE ............................................................................................................................... 3 STORAGE ...................................................................................................................................................... 4 CHAPTER 2 AIR CLEANERS ...................................................................................................................... 5 GENERAL INFORMATION ............................................................................................................................ 5 OPERATION .................................................................................................................................................. 5 COMPONENTS .............................................................................................................................................. 5 TROUBLESHOOTING OR TESTING ............................................................................................................ 5 SERVICE ....................................................................................................................................................... 6 DISASSEMBLY PROCEDURE ...................................................................................................................... 6 POLYURETHANE-TYPE FILTER ELEMENT ................................................................................................ 6 PAPER-TYPE FILTER ELEMENT ................................................................................................................. 6 CHAPTER 3 CARBURETORS AND FUEL SYSTEMS ................................................................................. 7 GENERAL INFORMATION ............................................................................................................................ 7 OPERATION .................................................................................................................................................. 8 FUEL PRIMERS ............................................................................................................................................. 8 IMPULSE FUEL PUMPS ................................................................................................................................ 9 FLOAT STYLE CARBURETORS ................................................................................................................... 9 DIAPHRAGM (PRESSURE DIFFERENTIAL) CARBURETORS .................................................................... 9 COMPONENTS ............................................................................................................................................ 10 CARBURETOR IDENTIFICATION ............................................................................................................... 11 DUAL SYSTEM CARBURETORS ................................................................................................................ 11 SERIES 1 CARBURETORS ......................................................................................................................... 11 SERIES 3 & 4 CARBURETORS .................................................................................................................. 11 DIAPHRAGM CARBURETORS ................................................................................................................... 11 SERIES 6 CARBURETORS 4-CYCLE ......................................................................................................... 12 SERIES 8 ..................................................................................................................................................... 12 SERIES 9 ..................................................................................................................................................... 12 SERIES 10 (EMISSION) .............................................................................................................................. 12 SERIES 11 ................................................................................................................................................... 12 SERIES 11 BRIDGED .................................................................................................................................. 13 NON-TECUMSEH CARBURETORS -- DELLORTO CARBURETOR ......................................................... 12 ENGINE TROUBLESHOOTING CHART ..................................................................................................... 13 CARBURETION TROUBLESHOOTING CHART ......................................................................................... 14 TESTING ...................................................................................................................................................... 15 SERVICE ..................................................................................................................................................... 15 CARBURETOR PRE-SETS AND ADJUSTMENTS ..................................................................................... 15 FINAL ADJUSTMENTS (NON-EMISSION ENGINES) ................................................................................. 16 NON-ADJUSTABLE CARBURETOR ........................................................................................................... 16 DISASSEMBLY PROCEDURE .................................................................................................................... 17 FLOAT STYLE CARBURETORS ................................................................................................................. 17 DIAPHRAGM CARBURETORS ................................................................................................................... 19 FLOAT ADJUSTING PROCEDURE ............................................................................................................. 19 INSPECTION ............................................................................................................................................... 20 ASSEMBLY .................................................................................................................................................. 21 STANDARD SERVICE CARBURETORS .................................................................................................... 24 CHAPTER 4 GOVERNORS AND LINKAGE ............................................................................................... 26 GENERAL INFORMATION .......................................................................................................................... 26 OPERATION ................................................................................................................................................ 26 INTERNAL COMPONENTS (VARIOUS STYLES) ....................................................................................... 26 TROUBLESHOOTING ................................................................................................................................. 26 ENGINE OVERSPEEDING .......................................................................................................................... 27 ENGINE SURGING ...................................................................................................................................... 27

C Tecumseh Products Company 1998

i

SERVICE ..................................................................................................................................................... 27 GOVERNOR ADJUSTMENT ....................................................................................................................... 27 GOVERNOR ADJUSTMENT PROCEDURE FOR SHORT BLOCK INSTALLATIONS ............................... 27 GOVERNOR GEAR AND SHAFT SERVICE ............................................................................................... 28 SPEED CONTROLS AND LINKAGE ........................................................................................................... 29 CHAPTER 5 REWIND STARTERS ............................................................................................................. 35 GENERAL INFORMATION .......................................................................................................................... 35 OPERATION ................................................................................................................................................ 35 COMPONENTS ............................................................................................................................................ 35 SERVICE ..................................................................................................................................................... 35 ROPE SERVICE .......................................................................................................................................... 35 RETAINER REPLACEMENT ....................................................................................................................... 36 STYLIZED REWIND STARTER (TVS, HM, TVM, TVXL), AND STAMPED STEEL STARTER (HM, VM, TVM, TVXL) ............................................................................................................................. 36 STYLIZED REWIND STARTER WITH PLASTIC RETAINER ...................................................................... 37 STANDARD STAMPED STEEL AND CAST ALUMINUM STARTER (HM, VM) .......................................... 38 VERTICAL PULL STARTER HORIZONTAL ENGAGEMENT TYPE ........................................................... 39 VERTICAL PULL STARTER VERTICAL ENGAGEMENT TYPE ................................................................. 40 CHAPTER 6 ELECTRICAL SYSTEMS ..................................................................................................... 42 GENERAL INFORMATION .......................................................................................................................... 42 OPERATION ................................................................................................................................................ 42 STARTING CIRCUIT AND ELECTRIC STARTERS .................................................................................... 42 CHARGING CIRCUIT .................................................................................................................................. 42 CONVERTING ALTERNATING CURRENT TO DIRECT CURRENT .......................................................... 43 HALF WAVE RECTIFIER SINGLE DIODE .................................................................................................. 43 FULL WAVE RECTIFIER BRIDGE RECTIFIER ........................................................................................... 43 COMPONENTS ............................................................................................................................................ 43 BATTERY ..................................................................................................................................................... 43 WIRING ........................................................................................................................................................ 43 ELECTRICAL TERMS .................................................................................................................................. 44 BASIC CHECKS ........................................................................................................................................... 45 TROUBLESHOOTING ELECTRICAL STARTER CIRCUIT FLOW CHART ................................................ 46 TROUBLESHOOTING ELECTRICAL CHARGING CIRCUIT FLOW CHART .............................................. 47 TESTING PROCEDURE .............................................................................................................................. 48 STARTING CIRCUIT .................................................................................................................................... 48 CHARGING CIRCUIT .................................................................................................................................. 48 VOLTAGE REGULATIONS .......................................................................................................................... 56 LOW OIL SHUTDOWN SWITCHES ............................................................................................................ 56 SERVICE ..................................................................................................................................................... 57 12 VOLT OR 120 VOLT ELECTRIC STARTERS WITH EXPOSED SHAFT ............................................... 57 12 VOLT D.C. OR 120 VOLT A.C. ELECTRIC STARTERS WITH THE STARTER GEAR UNDER THE CAP ASSEMBLY ............................................................................................................................. 57 INSPECTION ............................................................................................................................................... 58 CHAPTER 7 FLYWHEEL BRAKE SYSTEMS............................................................................................. 59 GENERAL INFORMATION .......................................................................................................................... 59 OPERATION ................................................................................................................................................ 59 BOTTOM SURFACE SYSTEM .................................................................................................................... 59 INSIDE EDGE SYSTEM .............................................................................................................................. 60 COMPONENTS ............................................................................................................................................ 60 SERVICE ..................................................................................................................................................... 61 FLYWHEEL REMOVAL ............................................................................................................................... 61 BRAKE LEVER AND PAD ........................................................................................................................... 61 IGNITION GOUNDOUT TERMINAL ............................................................................................................ 61 STARTER INTERLOCK SWITCH ................................................................................................................ 62 CONTROL CABLE ....................................................................................................................................... 62 BRAKE BRACKET REPLACEMENT ........................................................................................................... 62 CHAPTER 8 IGNITION ................................................................................................................................ 63 GENERAL INFORMATION .......................................................................................................................... 63 OPERATION ................................................................................................................................................ 63 SOLID STATE IGNITION SYSTEM (CDI) .................................................................................................... 63 MAGNETO IGNITION SYSTEM (POINTS) .................................................................................................. 63 ii

IDENTIFICATION OF TECUMSEH IGNITION SYSTEMS ........................................................................... 64 COMPONENTS ............................................................................................................................................ 64 IGNITION TROUBLESHOOTING ................................................................................................................ 66 TESTING PROCEDURE .............................................................................................................................. 67 SERVICE ..................................................................................................................................................... 68 SPARK PLUG SERVICE .............................................................................................................................. 68 CONDITIONS CAUSING FREQUENT SPARK PLUG FOULING ................................................................ 68 IGNITION TIMING PROCEDURE ................................................................................................................ 68 SERVICE TIPS ............................................................................................................................................. 71 CHAPTER 9 INTERNAL ENGINE AND CYLINDER ................................................................................... 72 GENERAL INFORMATION .......................................................................................................................... 72 OPERATION ................................................................................................................................................ 72 4-CYCLE ENGINE THEORY ....................................................................................................................... 72 LUBRICATION SYSTEMS ........................................................................................................................... 73 COUNTERBALANCE SYSTEMS ................................................................................................................. 73 COMPONENTS ............................................................................................................................................ 74 ENGINE OPERATION PROBLEMS ............................................................................................................. 75 TESTING ...................................................................................................................................................... 77 ENGINE KNOCKS ....................................................................................................................................... 77 ENGINE OVERHEATS ................................................................................................................................ 77 SURGES OR RUNS UNEVENLY ................................................................................................................ 77 ENGINE MISFIRES ...................................................................................................................................... 77 ENGINE VIBRATES EXCESSIVELY ........................................................................................................... 78 BREATHER PASSING OIL .......................................................................................................................... 78 EXCESSIVE OIL CONSUMPTION .............................................................................................................. 78 LACKS POWER ........................................................................................................................................... 78 SERVICE ..................................................................................................................................................... 79 DISASSEMBLY PROCEDURE .................................................................................................................... 79 CYLINDERS ................................................................................................................................................. 81 CYLINDER HEADS ...................................................................................................................................... 82 PISTONS, RINGS AND CONNECTING RODS ........................................................................................... 82 CRANKSHAFTS AND CAMSHAFTS ........................................................................................................... 84 VALVES ....................................................................................................................................................... 85 CRANKCASE BREATHERS ........................................................................................................................ 86 CYLINDER COVER, OIL SEAL, AND BEARING SERVICE ........................................................................ 87 CRANKSHAFT BEARING SERVICE ........................................................................................................... 88 COUNTERBALANCE SERVICE .................................................................................................................. 89 FLYWHEEL SERVICE ................................................................................................................................. 89 CHAPTER 10 ENGINE SPECIFICATIONS ................................................................................................. 90 FOUR CYCLE TORQUE SPECIFICATIONS ............................................................................................... 91 ENGINE SPECIFICATIONS STANDARD POINT IGNITION ....................................................................... 93 SOLID STATE AND EXTERNAL IGNITION ................................................................................................. 97 CHAPTER 11 EDUCATION MATERIALS AND TOOLS ........................................................................... 102 DECIMAL / FRACTION CONVERSIONS ................................................................................................... 105 SEARS CRAFTSMAN CROSS REFERENCE SUPPLEMENT INCLUDED IN BACK OF BOOK

iii

CHAPTER 1 GENERAL INFORMATION

ENGINE IDENTIFICATION Tecumseh engine model, specification, and serial numbers or (date of manufacture, DOM) are stamped into the blower housing or located on a decal on the engine in locations as illustrated (diag. 1 & 2).

COVER BEZEL

NOTE: On some LEV engines, a cover bezel must be removed to provide access to the identification decal (diag. 1). The engine identification decal also provides the applicable warranty code and oil recommendations (diag. 3).

MODEL AND D.O.M. NUMBER DECAL LOCATED UNDER COVER (IF SO EQUIPPED)

Emissionized engines that meet the California Air Resource Board (C.A.R.B.) or the Environmental Protection Agency (E.P.A.) standards will include additional required engine information on the engine decal (diag. 3).

PRESS IN AND LIFT HERE TO RELEASE COVER

Ç INTERPRETATION OF MODEL NUMBER The first letter designation in a model number indicates basic type of engine. V - Vertical Shaft LAV - Lightweight Aluminum Vertical VM - Vertical Medium Frame TVM - Tecumseh Vertical (Medium Frame) VH - Vertical Heavy Duty (Cast Iron) TVS - Tecumseh Vertical Styled TNT - Toro N’ Tecumseh ECV - Exclusive Craftsman Vertical TVXL - Tecumseh Vertical Extra Life LEV - Low Emissions Vertical H - Horizontal Shaft HS - Horizontal Small Frame HM - Horizontal Medium Frame HHM - Horizontal Heavy Duty (Cast Iron) Medium Frame HH - Horizontal Heavy Duty (Cast Iron) ECH - Exclusive Craftsman Horizontal HSK - Horizontal Snow King

1

HS50 67355H

SER 4091D

2

1

The number designations following the letters indicate the horsepower or cubic inch displacement. The number following the model number is the specification number. The last three numbers of the specification number indicate a variation to the basic engine specification. The serial number or D.O.M. indicates the production date.

FUEL REGULAR UNLEADED OIL, SAE 30 (BELOW 32oF SAE 5W30) LEV115 57010B (D) STP185U1G1RA 8105C

Using model LEV115-57010B, serial 8105C as an example, interpretation is as follows: LEV115-57010B is the model and specification number LEV

Low Emissions Vertical

115

Indicates a 11.5 cubic inch displacement

57010B is the specification number used for properly identifying the parts of the engine 8105C

is the serial number or D.O.M. (Date of Manufacture)

8

first digit is the year of manufacture (1998)

105

indicates calendar day of that year (105th day or April 15, 1998)

C

represents the line and shift on which the engine was built at the factory.

THIS ENGINE MEETS 1995-1998 CALIF. EMISSION REGULATOR FOR ULGE ENGINES AS APPLICBLE

FUEL: REGULAR UNLEADED OIL: USE SEA30

LEV115 57010B (D) STP185U1G1RA 8105C

Engine Family: Engine Tracking Information

SHORT BLOCKS New short blocks are identified by a tag marked S.B.H. (Short Block Horizontal) or S.B.V. (Short Block Vertical). Original model identification numbers of an engine should always be transferred to a new short block for correct parts identification (diag. 4).

THIS SYMBOL POINTS OUT IMPORTANT SAFETY INSTRUCTIONS WHICH IF NOT FOLLOWED COULD ENDANGER THE PERSONAL SAFETY OF YOURSELF AND OTHERS. FOLLOW ALL INSTRUCTIONS.

3

SHORT BLOCK IDENTIFICATION TAG

SBV OR SBH IDENTIFICATION NUMBER

SBV-2316 SER 4291 SERIAL NUMBER

4

FUEL Tecumseh strongly recommends the use of fresh clean unleaded regular gasoline in all engines. Unleaded gasoline burns cleaner, extends engine life and promotes better starting by reducing build-up of combustion chamber deposits. REFORMULATED AND OXYGENATED FUELS Reformulated fuels containing no more than 10% Ethanol, 15% MTBE, 15% ETBE or premium gasoline can be used if unleaded regular gasoline is not available. Leaded fuel may be used in countries where unleaded fuel is not available. NEVER USE FUEL CONTAINING METHANOL.

2

ENGINE OIL Use a clean, high quality detergent oil. Be sure original container is marked: A.P.I. service SF thru SJ. The use of multigrade oil may increase oil consumption under high temperature, high load applications. NOTE: DO NOT USE SAE10W40 OIL. For summer (above 32°F, 0oC) use SAE 30 oil part # 730225 (1 quart, .946 liter container) in high temperature, high load applications. S.A.E.10W30 is an acceptable substitute. For winter (below 32°F, 0oC) use S.A.E. 5W30 oil part # 730226 (1 quart, .946 liter container) S.A.E.10W is an acceptable substitute. S.A.E. 0W30 should only be used when ambient temperature is below 0oF, -18oC.

CAPACITIES: Engine Model LAV30-50, TVS75-120, LEV80-120 ECV100-120, TNT100-120 V & VH50, 60, 70 TVM 125, 140 TVM & TVXL 170, 195, 220 VM70, 80, 100 VH100 H & HSK30, 35, HS & HSSK40, 50 H, HH & HSK50, 60, 70 HM & HMSK70, 80, 100

Oz. 21 21 27 27 32 32 50 21 19 26

mL. 630 630 810 810 960 960 1500 630 570 720

EUROPA MODELS Oz. Vantage 21 Prisma 21 Synergy 21 Synergy "55" 27 Spectra 21 Futura 21 Centura 21 HTL 21 BVS 21 BH Series 21 Geo Tech Series 35-50 21

mL. 630 630 630 810 630 630 630 630 630 630 630

Oil Change Intervals. Change the oil after the first two (2) hours of operation and every 25 hours thereafter, or more often if operated under dusty or dirty conditions, extreme temperature, or high load conditions.

Oil Check. Check the oil each time the equipment is used or every 5 hours. Position the equipment so the engine is level when checking the oil. CAUTION: REMOVE THE SPARK PLUG WIRE BEFORE DOING ANY SERVICE WORK ON THE ENGINE. Oil Change Procedure: Locate the oil drain plug. On some units this plug is located below the deck through the bottom of the mounting flange. Other units drain at the base of the engine above the deck or frame. If access to the drain plug is restricted by the equipment it may be necessary to drain the oil by tipping the mower in a position that would allow the oil to drain out of the fill tube. On units that the drain plug is accessible, remove the plug and allow the oil to drain into a proper receptacle. Always make sure that drain oil is disposed of properly. Once the oil is drained, reinstall the plug and fill the engine with new oil to the proper capacity.

TUNE-UP PROCEDURE. The following is a minor tune-up procedure. When this procedure is completed, the engine should operate properly. Further repairs may be necessary if the engine's performance remains poor. CAUTION: REMOVE THE SPARK PLUG WIRE BEFORE DOING ANY SERVICE WORK ON THE ENGINE. 1. Service or replace the air cleaner as needed. 2. Inspect the level and condition of the oil and change or add oil as required. 3. Remove the blower housing and clean all dirt, grass or debris from the intake screen, cylinder head, cylinder cooling fins, carburetor, governor levers and linkage. 4. Make sure the fuel tank, fuel filter and fuel line are clean. Replace any worn or damaged governor springs or linkage. Make the proper governor adjustments and carburetor presets where required. 3

5. When replacing the spark plug, consult the parts breakdown for the proper spark plug to be used in the engine being serviced. Set the spark plug gap to .030" (.762 mm) and install the spark plug in the engine. Tighten the spark plug to 15 foot pounds of torque (20.4 Nm). If a torque wrench isn’t available, screw the spark plug in as far as possible by hand, and use a spark plug wrench to turn the spark plug 1/8 to 1/4 turn further if using the old spark plug, or 1/2 turn further if using a new spark plug. 6. Make sure all ignition wires are free of abrasions or breaks and are properly routed so they will not rub on the flywheel. 7. Properly reinstall the blower housing, gas tank, fuel line and air cleaner assembly if removed. 8. Make sure all remote cables are properly adjusted for proper operation. See chapter 4 under "Speed Controls and Linkage". 9. Reinstall the spark plug wire, add fuel and oil as necessary, and start the engine.

STORAGE: (IF THE ENGINE IS TO BE UNUSED FOR 30 DAYS OR MORE) CAUTION: NEVER STORE THE ENGINE WITH FUEL IN THE TANK INDOORS , IN ENCLOSED POORLY VENTILATED AREAS WHERE FUEL FUMES MAY REACH AN OPEN FLAME, SPARK OR PILOT LIGHT AS ON A FURNACE, WATER HEATER, CLOTHES DRYER OR OTHER GAS APPLIANCE. Gasoline can become stale in less than 30 days and form deposits that can impede proper fuel flow and engine operation. To prevent deposits from forming, all gasoline must be removed from the fuel tank and the carburetor. An acceptable alternative to removing all gasoline is adding a fuel stabilizer to the gasoline. Fuel stabilizer (such as Tecumseh's Part No. 730245) is added to the fuel tank or storage container. Always follow the mix ratio found on the stabilizer container. Run the engine at least 10 minutes after adding the stabilizer to allow it to reach the carburetor. CAUTION: THE USE OF SOME ANTI-ICING ADDITIVES MAY CREATE A METHANOL FUEL BLEND. DO NOT USE ADDITIVES THAT CONTAIN METHANOL. FUEL CONDITIONERS THAT CONTAIN ISOPROPYL ALCOHOL IS RECOMMENDED. Draining the Fuel System: CAUTION: DRAIN THE FUEL INTO AN APPROVED CONTAINER OUTDOORS, AND AWAY FROM ANY OPEN FLAME OR COMBUSTION SOURCE. BE SURE THE ENGINE IS COOL. 1. Remove all gasoline from the fuel tank by running the engine until the engine stops, or by draining the fuel tank by removing the fuel line at the carburetor or fuel tank. Be careful not to damage the fuel line, fittings, or fuel tank. 2. Drain the carburetor by pressing upward on the bowl drain (if equipped) which is located on the bottom of the carburetor bowl. On carburetors without a bowl drain, the carburetor may be drained by loosening the bowl nut on the bottom carburetor one full turn. Allow to completely drain and retighten the bowl nut being careful not to damage the bowl gasket when tightening. 3. If "Gasohol" has been used, complete the above procedure and then put one half pint of unleaded gasoline into the fuel tank and repeat the above procedure. If Gasohol is allowed to remain in the fuel system during storage, the alcohol content will cause rubber gaskets and seals to deteriorate.

Change Oil: If the oil has not been changed recently, this is a good time to do it. Oil Cylinder Bore: 1. Disconnect the spark plug wire and ground the wire to the engine. Remove the spark plug and put 1/2 ounce (14 ml) of clean engine oil into the spark plug hole. 2. Cover the spark plug hole with a shop towel. 3. Crank the engine over slowly several times. CAUTION: AVOID SPRAY FROM SPARK PLUG HOLE WHEN SLOWLY CRANKING ENGINE OVER. 4. Install the spark plug and connect the spark plug wire.

Clean Engine: Remove the blower housing and clean all dirt, grass or debris from the intake screen, cylinder head, cylinder cooling fins, carburetor, governor levers and linkage.

4

CHAPTER 2 AIR CLEANERS GENERAL INFORMATION The air cleaner is the device used to eliminate dust and dirt from the air supply. Filtered air is necessary to assure that abrasive particles are removed before entering the carburetor and combustion chamber. Dirt allowed into the engine will quickly wear the internal components and shorten the life of the engine. Tecumseh engines use either a polyurethane or a papertype air filter system. A polyurethane pre-cleaner or a flocked screen may be used in conjunction with the main filter. Snow King® engines do not use an air filter.

COVER

Extremely dirty conditions may require more frequent filter cleaning or replacement.

POLYURETHANE WRAP

OPERATION

SEALING NUTS PAPER ELEMENT

The outer cover encapsulates the air filter element(s) and prevents large particles from entering the filter box. Air is filtered through the pre-cleaner or flocked screen (if equipped) and the polyurethane or paper filter element. Pre-cleaners or flocked screens provide additional air cleaning capacity. In Tecumseh's Kleen Aire® system, air is drawn in through a rotating screen or recoil cover to be centrifugally cleaned by the flywheel before the air is drawn into the air filter.

AIR CLEANER BODY

COMPONENTS (diag 1 & 2) 1 The cover holds the filter element and prevents large debris from entering the filter element. The polyurethane wrap pre-filter is used on XL or XL/C engine models with paper filter elements. The paper or polyurethane filter element is the main filter to trap dust and dirt. Dry-type paper elements have treated paper folded for increased surface area and rubberlike sealing edges. The polyurethane filter uses an oil film to trap fine particles found in dust.

COVER

The flocked screen is used as an additional filter on XL or XL/C engine models that use a polyurethane filter element.

TROUBLESHOOTING OR TESTING If the engine's performance is unsatisfactory (needs excessive carburetor adjustments, starts smoking abnormally, loses power), the first engine component to be checked is the air cleaner. A dirt restricted or an oil soaked element will cause noticeable performance problems. A polyurethane element may be cleaned following the service procedure listed under "Service" in this chapter. A papertype air filter should only be replaced. A paper-type element cannot have an oil film present on the paper. Follow the procedure listed in the "Service" section of this chapter for replacement. Re-try the engine after filter replacement or service. If the problem persists after filter service, see Chapter 9 under "Engine Operation Problems" for additional causes.

AIR CLEANER BODY

FOAM ELEMENT

FLOCKED SCREEN

2 5

SERVICE Service on the polyurethane element (cleaning and oiling) is recommended every three months or every twenty five operating hours, whichever comes first. Extremely dirty or dusty conditions may require daily cleanings. The paper filter element should be replaced at least once a year or more frequently if operated in dusty or dirty conditions. NOTE: NEVER RUN THE ENGINE WITHOUT THE COMPLETE AIR CLEANER ASSEMBLY INSTALLED ON THE ENGINE. ALWAYS REPLACE THE FILTER ELEMENT WITH THE PROPER TECUMSEH ORIGINAL REPLACEMENT PART.

DISASSEMBLY PROCEDURE 1. Unlock the tabs or remove the screws, wingnuts or snaps holding the air cleaner cover in place. 2. Remove the hex nuts holding the element down if equipped. New nuts are supplied with a new filter and MUST be used for proper sealing. FOAM ELEMENT

3. Clean the excess contaminants out of the air cleaner body before removing the old element. 4. Remove the old element and the polyurethane precleaner if equipped. 5. On air cleaners that use a flocked screen under the polyurethane element, remove the air cleaner assembly from the carburetor before removing the flocked screen. This prevents dirt from entering the carburetor (diag 3).

1/2" (12.7 mm) FOAM WITH FLOCKED SCREEN ATTACHED

6. Clean the inside of the cover and body, remove the old gasket between the carburetor and the air cleaner assembly. 7. Reinstall the air cleaner assembly using a new gasket. 8. Use the reverse procedure for reassembly. When installing the foam polyurethane pre-cleaner, make sure the seam is installed to the outside to prevent gaps between the paper element and the pre-cleaner.

AIR CLEANER BODY

3

POLYURETHANE-TYPE FILTER ELEMENT This type of air filter can be serviced when restricted with dust or dirt. Wash the filter or pre-cleaner in a liquid detergent and water solution until all the dirt is removed. Rinse in clear water to remove the detergent solution. Squeeze the element (do not twist) to remove the excess water. Wrap the element in a clean cloth and squeeze it (do not twist) until completely dry. Re-oil the element by applying engine oil and squeezing it vigorously to distribute the oil. Roll the element in a cloth and squeeze it (do not twist) to remove the excess oil. Clean the air cleaner housing and cover being careful not to allow dirt to fall into the carburetor or intake pipe.

PAPER -TYPE FILTER ELEMENT Paper type air filter elements can only be serviced by replacement. Do not attempt to clean a paper filter element.

6

CHAPTER 3 CARBURETORS AND FUEL SYSTEMS GENERAL INFORMATION Tecumseh uses two basic types of carburetors, float and diaphragm type carburetors. Float type carburetors use a hollow float to maintain the operating level of fuel in the carburetor. Diaphragm type carburetors use a rubber-like diaphragm. One side is exposed to intake manifold pressure and the other side to atmospheric pressure. The diaphragm provides the same basic function (maintaining the proper fuel level in the carburetor) as the float. An advantage of the diaphragm carburetor over the float style is that the diaphragm carburetor will allow the engine to operate at a greater degree of tiltability. Tecumseh carburetors are identified by a manufacturing number and date code stamped on the carburetor as illustrated (diag. 1).

Complete carburetor replacement may be accomplished with a standard service carburetor. A standard service carburetor is a basic carburetor that may require the use of original carburetor parts or additional new parts to adapt to the specification. An instruction sheet is provided with the new service carburetor or see “SERVICE” in this chapter.

ALTERNATE LOCATION FOR MANUFACTURING NUMBER 4F5 89

When servicing carburetors, use the engine model and specification number to obtain the correct carburetor part number. An alternate method of finding the correct carburetor part number is to use the manufacturing number stamped on the carburetor and convert this number to a part number. In the carburetor section of the Master Parts Manual, Microfiche Catalog or computer parts look-up system, a cross reference chart will convert a carburetor manufacturing number to a Tecumseh part number.

89 4F5

MANUFACTURING NUMBER

CARBURETOR DATE CODE

1

CAUTION: DRAIN THE FUEL INTO AN APPROVED CONTAINER OUTDOORS, AND AWAY FROM ANY OPEN FLAME OR COMBUSTION SOURCE. BE SURE THE ENGINE IS COOL. NOTE: Todays fuels can cause many problems in an engines performance, due to the fuels quality and short shelf life. Always check fuel as a primary cause of engine performance. 1. Remove the air filter, heater box, or air cleaner assembly if applicable to visually check that the choke shutter completely closes or check to see if fuel comes out of the main nozzle during priming. 2. If the fuel flow from the tank is adequate and no fuel is evident during priming, the carburetor will need to be removed for service. See “Service” in this chapter or consult the “Carburetion Troubleshooting” chart to diagnose carburetor symptoms. Improper fuel flow indicates the fuel, fuel line, filter or tank require cleaning or replacement. 3. Check the engine compression using a commercially available compression tester and follow the tester’s recommended procedure. Low compression, a dry spark plug, adequate fuel flow, and a known good functional carburetor indicates an internal engine problem exists. See under “Troubleshooting.” 4. A wet spark plug indicates fuel is being supplied by the carburetor. The engine may be flooded by a restricted air filter, carbon shorted or defective spark plug, excessive choking or over priming, improperly adjusted or defective carburetor. With the spark plug removed and a shop towel over the spark plug hole, turn the engine over slowly 3 or 4 times to remove excess gasoline from the engine cylinder. CAUTION: KEEP ALL COMBUSTIVE SOURCES AWAY. AVOID THE SPRAY FROM THE SPARK PLUG HOLE WHEN CRANKING THE ENGINE OVER. 5. Replace the air filter if restricted or oil soaked. Replace the spark plug if questionable. Install the spark plug and high tension lead and try to start the engine. 6. If the engine floods and fails to start, the carburetor will require service. See the proceeding “Carburetion Troubleshooting” chart for additional causes. If the carburetor is functioning properly the problem may be ignition timing related. See “Troubleshooting" under "Ignition”. 7

OPERATION In the “CHOKE” or “START” position, the choke shutter is closed and the only air entering the engine enters through openings around the shutter. As the engine starts to rotate, downward piston travel creates a low air pressure area (or vacuum) above the piston. Higher pressure (atmospheric) air rushes into the engine and fills this low pressure area. Since the majority of the air passage is blocked by the choke shutter, a relatively small quantity of air enters the carburetor at an increased speed. The main nozzle and both idle fuel discharge ports are supplying fuel due to the low air pressure in the engine intake. Maximum fuel flow through the carburetor orifices combined with the reduced quantity of air that passes through the carburetor, make a very rich fuel mixture which is needed to start a cold engine. At engine IDLE speed, a relatively small amount of fuel is required to operate the engine. The throttle is almost completely closed. Fuel is supplied through the primary idle-fuel discharge orifice. NOTE: Dual system carburetors do not have an idle circuit. During INTERMEDIATE engine operation, a second orifice is uncovered as the throttle shutter opens, and more fuel is allowed to mix with the air flowing into the engine. During HIGH SPEED engine operation, the throttle shutter is fully opened. Air flows through the carburetor at high speed. The venturi, which decreases the size of the air passage through the carburetor, further accelerates the air flow. This high speed movement of the air decreases the air pressure at the main nozzle opening. Fuel is forced out the main nozzle opening due to the difference in the air pressure on the fuel in the carburetor bowl and the reduced air pressure at the main nozzle opening. For the fuel to flow, the carburetor bowl must be either vented externally or internally. Some internally vented float style carburetors use a tygon tube and a vent within the air intake. This tube must be present for the carburetor to operate properly (diag. 2). Air is bled into the main nozzle and through the air bleed located in the air horn. This mixes the fuel and air prior to the fuel leaving the main nozzle. Atomization occurs as the fuel mixture contacts the fast moving air stream. This mist then flows into the intake of the engine.

FUEL PRIMERS Primers may be mounted remotely or as an integral part of the carburetor. The basic function of the primer is to supply a charge of air to the carburetor main well, or carburetor bowl. On diaphragm carburetors it displaces fuel directly into the carburetor venturi. This displaced fuel provides a rich mixture necessary for engines to start easily on the first or second attempt (diag. 3 & 4).

TYGON TUBE LOCATION

2

PRIMER BULB PRIMER BULB

Primers must be vented either internally (a passage in the carburetor air horn prior to the venturi) or externally (through a hole in the primer bulb). The vent allows air to fill the primer bulb after the primer bulb is released. On diaphragm carburetors a one way valve in the body prevents the fuel from being forced back into the fuel tank. Two different methods are used to prime float style carburetors, leg prime and bowl prime. The leg prime system is used only on the dual system carburetor. Air is forced into the center leg of the carburetor, which then forces an enriched mixture of fuel up the main nozzle. The bowl prime method is used on Series 6, 8, 9 and 10 carburetors and is distinguished by a stepped or hour glass shaped primer bulb. A good seal of the primer bulbs center lip is critical to assure that a full charge of air reaches the bowl. Also critical is a tight seal around the float bowl.

3

MAIN NOZZLE EMULSION MAIN JET TUBE

4

BOWL PRIME

NOTE: Never re-use a bowl gasket. 5 8

IMPULSE FUEL PUMPS Impulse fuel pumps may either be mounted externally onto the carburetor fuel inlet or remotely mounted. These pumps are connected in the fuel line between the fuel supply and the carburetor or directly to the fuel inlet. Impulse fuel pumps are operated by crankcase impulses created by the up and down movement of the piston. A hose called a pulse line connects the fuel pump diaphragm chamber to the crankcase and transmits these impulses to the pump diaphragm. The impulses actuate the diaphragm and flap valves to lift the fuel from the fuel tank to the carburetor (diag. 6).

FLOAT STYLE CARBURETORS A float is used to maintain the operating volume of fuel in the carburetor bowl. As the fuel is used by the engine, the fuel volume in the carburetor bowl drops and the float moves downward. This allows the inlet needle valve to move off the sealing seat. Fuel flows by gravity or a pulse pump into the fuel bowl. As the fuel volume in the bowl again rises, it raises the float. This upward float motion moves the inlet needle valve to the closed position. When the needle contacts the seat, the fuel flow is stopped. The tapered end of the inlet needle varies the fuel flow rate so that the fuel volume in the carburetor bowl will remain constant (diag. 7). The float height is set according to the service procedure.

DIAPHRAGM (PRESSURE DIFFERENTIAL) CARBURETORS This type of carburetor uses a rubber-like diaphragm which is exposed to intake manifold pressure on one side and to atmospheric pressure on the other. Tecumseh diaphragm carburetors use the diaphragm as a metering device. As the intake manifold pressure decreases due to downward piston travel, the atmospheric pressure on the vented side of the diaphragm moves the diaphragm against the inlet needle. The diaphragm movement overcomes the spring tension on the inlet needle and moves the inlet needle off the seat. This permits the fuel to flow through the inlet valve to maintain the correct fuel volume in the fuel chamber. The inlet needle return spring closes the inlet valve when the pressure on the diaphragm equalizes or a pressure higher than atmospheric exists on the intake side (upward piston travel). The diaphragm meters a correct fuel volume in the fuel chamber to be delivered to the mixing passages and discharge ports (diag. 8). A main or idle adjustment needle may be replaced by an internally fixed jet on some models. The main nozzle contains a ball check valve. The main purpose of this ball check is to eliminate air being drawn down the main nozzle during idle speeds and leaning the idle mixture.

6 IDLE AND PROGRESSION HOLES

IDLE AIR BLEED

MAIN AIR BLEED CHOKE SHUTTER

THROTTLE SHUTTER

INLET NEEDLE AND SEAT IDLE ADJUSTMENT

MAIN NOZZLE EMULSION TUBE

FLOAT MAIN ADJUSTMENT

7

CHECK BALL THROTTLE SHUTTER

CHOKE SHUTTER

IDLE ADJUSTMENT

MAIN ADJUSTMENT

NEEDLE AND SEAT ASSEMBLY

DIAPHRAGM

8

An advantage of the diaphragm carburetor over the float system is that the diaphragm carburetor increases the angle that the engine may be operated at. 9

COMPONENTS Loosen screw until it just clears throttle lever, then turn screw in 1 turn. IDLE SPEED ADJUSTMENT SCREW

CHOKE SHAFT AND LEVER Check shaft for binding. Position shutter opening towards inlet fitting side or CHOKE SHUTTER air horn.

THROTTLE SHAFT AND LEVER MAIN NOZZLE

Place detent reference mark to proper DETENT REFERENCE MARK location. ON THROTTLE SHUTTER THROTTLE SHUTTER

*INLET FITTING SCREEN

Check spring for return action and bind- THROTTLE SHAFT RETURN SPRING ing.

Blow air through passage.

Part of inlet fitting. If fuel is restricted, clean or replace fitting.

*INLET FITTING Bulb primer models have Viton* one way valve, in or behind fitting.

Remove welch plug and blow air through air passages.

IDLE IDLE PROGRESSION HOLE

*INLET SEAT Remove and replace. GASKET

IDLE AIR BLEED

*IDLE MIXTURE ADJUSTMENT Remove adjustment screw. To adjust SCREW AND "O" RING (If Present) 20° slant engines, the engine must be mounted in its normal 20° slant posi*MAIN MIXTURE tion. ADJUSTMENT SCREW AND "O" RING (If Present)

*INLET NEEDLE SEAT AND SPRING ASSEMBLY

*DIAPHRAGM GASKET Check ball is not serviceable on some WELCH PLUG (If Present) models. *MAIN NOZZLE CHECK BALL (If Present)

*DIAPHRAGM

ATMOSPHERIC VENT HOLE *NON METALLIC ITEMS - CAN BE DAMAGED BY HARSH CARBURETOR CLEANERS

Blow air through passage.

Proper installation of assembly is important.

Gasket and diaphragm sequence may be reversed on some models. Head of rivet must touch inlet needle. Rivet is hooked into inlet needle control lever on some models.

Hole must be clean. On models with bulb primer, vent hole is very small and is located off center.

9

IDLE AND INTERMEDIATE AIR BLEED

Check shaft for looseness or binding. THROTTLE SHAFT AND LEVER Shutter must be positioned with detent reference marks on top parallel with THROTTLE SHUTTER shaft and to the right or 3 o'clock position. DETENT REFERENCE MARK

IDLE SPEED ADJUSTMENT

Loosen screw until it just clears throttle lever, then turn screw in one turn.

MAIN NOZZLE (EMULSION TUBE)

Removable on emission carbs. nonmetallic only.

CHOKE SHAFT AND LEVER

Check shaft for binding position opening to bottom of air horn.

CHOKE PLATE Check spring for return action and binding.

THROTTLE SHAFT RETURN SPRING HIGH SPEED AIR BLEED

Blow air through passage. Do not remove restrictor if present.

IDLE AND INTERMEDIATE ORIFICES INLET FITTING

Remove idle adjustment screw. Check IDLE AND INTERMEDIATE needle tip and condition of "O" ring. FUEL CHAMBER (COVERED Remove welch plug and blow out all WITH WELCH PLUG) passages. IDLE AND INTERMEDIATE FUEL MIXTURE PASSAGE

*INLET NEEDLE AND SEAT

Proper installation is important.

*IDLE ADJUSTMENT SCREW AND "O" RING

FLOAT SHAFT

ATMOSPHERIC VENT SOFT BAFFLE PLUG

METERING ROD OR PIN IN FUEL TRANSFER PASSAGE BALL PLUG

(DO NOT REMOVE)

INLET NEEDLE CLIP (If Present)

Must hook over float tab.

*GASKET

CUP PLUG IDLE AND INTERMEDIATE FUEL TRANSFER PASSAGE

IDLE AND MAIN FUEL PICK UP ORFICE *NON METALLIC ITEMS - CAN BE DAMAGED BY HARSH CARBURETOR CLEANERS

10

Replace.

IDLE FUEL TRANSFER PASSAGE AND ANNULAR GROOVE Check float for leaks or dents. Clean FLOAT bowl and adjust float level position gasket or gaskets. FLOAT BOWL

IDLE AND INTERMEDIATE FUEL TRANSFER PASSAGE

NOTE: On models which have metering rods, do not install idle adjustment screw with carburetors upside down, as pin will obstruct movement of adjustment screw causing damage

*FLOAT BOWL GASKET

NUT AND MAIN ADJUSTMENT SEAT *MAIN ADJUSTMENT SCREW AND "O" RING SEAL

If the carburetor is used on a 20° slant engine, the engine must be in its normal 20° slanted position for adjustment. Check needle for damage and "O" ring for cracks. Clean all passages in nut with compressed air.

10

CARBURETOR IDENTIFICATION Tecumseh has a variety of carburetors. To help identify these carburetors here are some simple procedures to follow.

DUAL SYSTEM CARBURETORS The easiest way to identify the dual system carburetor is by the presence of a large primer bulb located on the side of the carburetor. The absence of adjustment needles help to identify the carb as well. The dual system carburetor is used on 4-cycle vertical crankshaft rotary mower engines. (diag. 11). 11

SERIES 1 CARBURETORS Series 1 carburetors come in a variety of styles. They are used on both 2 and 4 cycle vertical and horizontal shaft engines in the 2 through 7 h.p. range. It is a float style carburetor with a smaller venturi than the Series 3 and 4 carburetors. Some will have an adjustable idle and main and others will have a fixed main with an adjustable idle. There are also some fixed speed applications that will only have a fixed main system and the idle system will not be drilled. (diag. 12).

12

NOTE: Emissionized carburetors will have a fixed jet.

SERIES 3 & SERIES 4 CARBURETORS Series 3 and 4 carburetors are generally used on 8 through 12.5 horsepower 4-cycle engines. The venturi size of these carburetors are larger than Series 1 and Dual System Carburetors. The quickest way to identify these carburetors is by the presence of bosses on each side of the idle mixture screw. To identify the Series 3 from a Series 4, view the carburetor from the throttle end. The Series 3 has (1) screw securing the throttle plate and the Series 4 uses (2) screws. (diag. 13 - 15)

BOSSES

13

SERIES 3

14

SERIES 4

15

DIAPHRAGM CARBURETORS The diaphragm carburetors are unique. These carburetors can be operated at a more severe angle than float style carburetors. They still require that the fuel supply be located in a position that allows it to be gravity fed. Its most distinctive feature is the lack of a fuel bowl. (diag. 16). NOTE: Emissionized carburetors will have a fixed jet. 16 11

SERIES 6 CARBURETORS 4-CYCLE Series 6 carburetors are used on 2 and 4-cycle engines. They have a larger venturi than the dual system carburetor and use a simple fixed idle system. Series 6 carburetors used on both vertical and horizontal applications are nonadjustable. The 4 cycle version pictured has a stepped primer bulb. (diag. 17). 17

SERIES 8 The Series 8 carburetor has both a fixed main and idle circuit. The fixed idle system uses a restricted jet that meters the fuel. The idle restrictor jet will be capped to prevent access unless removed. The fixed main jet is part of the bowl nut. A ball plug is visible from the bottom, which seals the metering passage. This carburetor also has a serviceable main nozzle emulsion tube. It also has a stepped primer bulb to assist in starting. (diag. 18)

SERIES 9 The Series 9 carburetor uses the same body as the Series 8 but has a simple fixed idle system, identical to the one used on the Series 6 carburetor. It has the idle discharge port located at the 7 o'clock position on the throttle end of the carburetor. Identify this carburetor by the stepped primer bulb, the presence of a non-drilled idle mixing well and a serviceable main nozzle emulsion tube. (diag. 19)

GREY CAPPED FIXED JET

18

MIXING WELL CAST BUT NOT MACHINED

IDLE JET CAST BUT NOT MACHINED

19

SERIES 10 (EMISSION) The Series 10 carburetor is identical to the Series 8 carburetor with the addition of a choke to assist in cold weather starts. It also has a fixed idle and main. The idle restrictor jet is capped to prevent access unless the cap is removed. The fixed main jet is part of the bowl nut. A ball plug is visible from the bottom, which seals the metering passage. This carburetor also has a serviceable main nozzle emulsion tube and a stepped primer bulb to assist in starting. (diag. 20)

20

SERIES 11 The Series 11 carburetor is used on most LEV model engines. This carburetor contains a patented autoenrichment system for improved starting and performance of a cold engine. The system contains a fuel well that is filled as part of the priming procedure and emptied as the engine runs in the first minute. This added fuel provides smooth operation of today’s emission grade engines. The carburetor can be identified externally by the BLACK colored restrictor cap (diag. 21). Internally the standard Series 11 is identified by the plugged passage as shown.

BLACK CAP

HOLE PLUGGED

21 12

SERIES 11 BRIDGED Externally this carburetor looks identical to the standard series 11 with the black restrictor cap. The difference is internal through the addition of a second idle feed passage with a restrictor as shown. This extra passage improves run quality during light load engine operation (diag. 22). BLACK CAP

ADDED RESTRICTOR

22

NON-TECUMSEH CARBURETORS DELLORTO CARBURETOR The Dellorto carburetor is similar to the dual system carburetor. It has no adjustments and has a primer assist start. It has a noncorrosive float and the needle is viton tipped, eliminating the viton seat found in the dual system carburetor. The angle of the fuel inlet is adjustable and attached to the carburetor body with a banjo bolt. This carburetor is used on some TVS rotary lawnmower engines.

23

ENGINE TROUBLESHOOTING Engine Will Not Start Check For Spark

Wet

Dry Check If Spark Plug Is Wet or Dry

Defective Spark Plug

Check Fuel Supply and Fuel Cap Vent

Restricted Air Filter

Restriction in Fuel System (filter, screen)

Improper or Stale Fuel

Carburetion Problem

Sheared or Partially Sheared Flywheel Key

Poor Compression

Carburetion Problems Due to Flooding, Over Priming, etc. Ignition System 13

CARBURETION TROUBLESHOOTING START

AIR SYSTEM PROBLEMS Plugged Air Filter

Fuel Leak Hard at Starting Carburetor

IDLE

Engine Floods

Á

Á Á

Leaky Carburetor Gasket Throttle or Choke Shafts Worn Choke Not Functioning Properly

Idles with Needle Closed

Hunts Erratic Idle

Idles Fast Lean

Á

Will Not Accelerate

Á Á

Á

Á

Á

Over Rich AcceleraHesitates tion

Á

HIGH SPEED

Will Not Run at High Speed

Low Power

Hunts at High Speed

Runs with Needle Closed

Engine Overspeeds

Á Á Á Á

Á

Á Á

Á Á

Á

Á

Plugged

Air Bleed

Rich Idle

Á

Á

Á

Atmospheric Vent

Restricted

Will Not Idle

ACCELERATE

Á Á

Á

Damaged or

Á Á

Á

Á

Leaky "O" Rings

Á

Á

Á

DIAPHRAGM SYSTEM PROBLEM Damaged Diaphragm

Á

Á

Á

Stuck or Dirty Ball

Á

Check Diaphragm Upside Down

Á Á

Á

Á

Á

Á

Á

Á

Á Á

Á

Á

Á

Á

Á Á

Á

Á

Á

Á Á Á

Á

Á Á

Á

Á

Á

FUEL SYSTEM PROBLEM Plugged Tank Filter or Vent Fuel Pick-up Restricted

Á Á

Idle Port Restricted Damaged Adjustment

Á

Height

Dirty, Stuck Needle and Seat Fuel Inlet Plugged

14

Á

Á

Á

Incorrect Float

Restricted

Á

Á

Needles

Main Nozzle

Á Á

Á

Á

Á

Á

Á

Á Á Á

Á Á

Á Á

Á

Á

Á

Á

TESTING 1. After repeated efforts to start the engine using the procedure listed in the operator’s manual fail, check for spark by removing the high tension lead and the spark plug. Install a commercially available spark plug tester and check for spark. If spark is evident and acceptable, proceed to step 2. If no or weak spark, see Chapter 8 under "Testing". 2. Visually inspect the spark plug for a wet condition indicating the presence of gasoline in the cylinder. 3. If the spark plug is dry, check for restrictions in the fuel system before the carburetor. If the spark plug is wet, continue with step # 7. Check to see if the fuel cap vent is open. With a proper draining receptacle, remove the fuel line clamp on the carburetor fuel inlet and pull the fuel line off the fitting to examine the fuel flow and fuel condition. 4. Remove the air cleaner element or air cleaner assembly to visually check that the choke shutter completely closes or check to see if fuel comes out from the main nozzle during priming. 5. If the fuel flow is adequate and no fuel is evident during priming, the carburetor will need to be removed for service. See “Service” in this chapter or consult the “Carburetion Troubleshooting” chart if other problems exist. Improper fuel flow indicates the fuel, fuel line, filter or tank require cleaning or replacement. 6. Check the engine compression using a commercially available compression tester and follow the tester’s recommended procedure. Low compression, a dry spark plug, adequate fuel flow, and a known good functional carburetor indicates an internal engine problem exists. See Chapter 9 under “Engine Operation Problems.” 7. A wet spark plug indicates fuel is being supplied by the carburetor. The engine may be flooded by a restricted air filter, carbon shorted or defective spark plug, excessive choking or over priming, improperly adjusted or defective carburetor, or the wrong ignition timing. With the spark plug removed and a shop towel over the spark plug hole, turn the engine over slowly 3 or 4 times to remove excess gasoline from the engine cylinder. CAUTION: KEEP ALL COMBUSTIVE SOURCES AWAY. AVOID THE SPRAY FROM THE SPARK PLUG HOLE WHEN CRANKING THE ENGINE OVER. 8. Replace the air filter if restricted or oil soaked. Replace the spark plug if questionable. Install the spark plug and high tension lead and retry starting the engine. 9. If the engine floods and fails to start, the carburetor may require service. See the preceding “Carburetion Troubleshooting” chart for additional causes. If the carburetor is functioning properly the problem may be ignition timing related. See Chapter 8 under “Ignition Troubleshooting.”

SERVICE CARBURETOR PRE-SETS AND ADJUSTMENT NOTE: EMISSION GRADE CARBURETORS HAVE FIXED IDLE AND MAIN JETS. THE ABSENCE OF THE ADJUSTING SCREW INDICATES A FIXED JET OR RESTRICTOR AND NO ADJUSTMENT IS NECESSARY. THE IDLE RESTRICTOR ON AN EMISSIONS CARBURETOR APPEARS AS AN ADJUSTABLE SCREW. THIS IS NOT ADJUSTABLE AND MUST REMAIN TIGHT FOR PROPER OPERATION. The idle on an emission is metered using a threaded restrictor (see Illustration). Proper torque of this screw is critical and should be torqued to 5-8 in. lbs. or .5 to 1 nm, if not, it may vibrate loose. When the restrictor is placed in the idle circuit passage it is capped with a tamper resistant plastic cap. Tampering is considered the rejetting or modification through resizing of the jet. If the jet is removed for cleaning it must be recapped to prevent tampering when it is re-installed.

IDLE RESTRICTOR CAP

Before adjusting any mixture screws the necessary carburetor presets should be made. Check for the proper governor adjustments as outlined in Chapter 4. Identify the correct carburetor model and manufacturer to find locations of the high and low speed adjustment screws. Check the throttle control bracket for proper adjustment allowing a full choke shutter position. See Chapter 4 under "Speed Controls and Linkage". Check to see if the normal maintenance procedures have been performed (oil changed, fresh fuel, air filter replaced or clean). Consult microfiche card #30 to find the correct R.P.M. settings for the engine, or consult Service Bulletin #107 for the revised safety specification for rotary type power lawn mowers. Start the engine and allow it to warm to operating temperature. The carburetor can now be adjusted. 15

PRE-SETS AND ADJUSTMENTS

Tecumseh Carburetors Engine Model

(TECUMSEH AND WALBRO CARBURETORS) NOTE: OVERTIGHTENING WILL DAMAGE THE TAPER PORTION OF THE NEEDLE. All adjustments should be made with the carburetor in the operating position.

All models with float-type carburetors All models with diaphragm-type carburetors

Main Pre-set

Idle Pre-set

1-1/2 turn

1 turn

1 turn

1 turn

Walbro Carburetors Carburetor Model Number

Turn both the main and idle mixture adjusting screws in (clockwise) until finger tight.

LMH

1-1/2 turn

1-1/2 turn

WHG & LME

1-1/4 turn

1-1/4 turn

Now back the mixture screws out (counterclockwise) to obtain the pre-set figure in the chart shown at right.

LMK

Fixed

1 turn

FINAL ADJUSTMENTS (NON EMISSION ENGINES) Start the engine and allow it to warm up to normal operating temperature (3 - 5 minutes). Set the speed control to the HIGH or FAST position. From the recommended preset position, turn the main mixture adjustment screw in (clockwise) slowly until the engine begins to run erratic (lean). Note the position of the screw. Now, turn the screw out (counterclockwise) until the engine begins to run erratic (rich). Turn the screw in (clockwise) midway between these two positions. This will be the best setting. (diag. 24, 25 & 26). Set the speed control to the IDLE or SLOW position. Adjust the idle mixture screw following the same procedure used to adjust the main mixture adjustment screw.

TECUMSEH CARBURETORS SERIES 1

IDLE MIXTURE SCREW

MAIN MIXTURE SCREW

DIAPHRAGM

SERIES 3 & 4

MAIN MIXTURE SCREW

IDLE MIXTURE SCREW

IDLE MIXTURE SCREW MAIN MIXTURE SCREW

24 25 If further adjustment is required, the main adjustment should be made under a loaded condition.

26

If the engine stops or hesitates while engaging the load (lean), turn the main mixture adjusting screw out (counterclockwise) 1/8 turn at a time, testing each setting with the equipment under load, until this condition is corrected. If the engine smokes excessively (rich), turn the main adjusting screw in (clockwise) 1/8 turn at a time, testing each setting with the equipment under load, until this condition is corrected. After the main mixture screw is set, move the speed control to the IDLE or SLOW position. If the engine does not idle smoothly, turn the idle mixture screw 1/8 turn either in (clockwise) or out (counterclockwise) until engine idles smoothly. Recheck the high and low R.P.M. setting and adjust as necessary.

NON-ADJUSTABLE CARBURETORS DUAL SYSTEM AND SERIES 6

NON-ADJUSTABLE PRIMER NO CHOKE

16

27

SERIES 8, 11 & BRIDGED 11

CAPPED FIXED JET

28

SERIES 9 MIXING WELL CAST BUT NOT MACHINED

IDLE JET CAST BUT NOT MACHINED

SERIES 10

29

CAPPED IDLE RESTRICTOR

CHOKE

30

DISASSEMBLY PROCEDURE NOTE: Engines which are identified as compliant with CARB (California Air Resources Board) or EPA (US Environmental Protection Agency) regulations can NOT be changed from the factory settings unless specifically authorized.

FLOAT STYLE CARBURETORS 1. Note or mark the high and low mixture adjusting screws to aid in reassembly (if applicable). Remove the high speed adjusting screw, bowl nut, and float bowl. Remove the idle mixture screw assembly. 2. Note the position of the spring clip on the inlet needle and float, the long end of the clip must face toward the choke end of the carburetor. Remove the float hinge pin with a needlenose pliers. Some carburetors use a float dampening spring to aid the inlet valve in maintaining a steady position during rough service applications. Note the position of the hooks before removing the float hinge pin (diag. 31).

LONG END OF CLIP TOWARD CHOKE

CLIP OPEN END OF CLIP THROTTLE END

CHOKE END

31

3. Remove the float, clip, and inlet needle. 4. Remove the inlet needle seat using the Tecumseh carburetor tool #670377 as shown. Push the hook through the hole in the center of the seat to remove it. (diag. 32). 5. Note or mark the action of the choke and throttle shutters, and/or the hook points of the choke or throttle return spring, or seal retainer springs located on the top of the choke and/or throttle shaft. Remove the throttle shutter, throttle shaft, choke shutter, springs and choke shaft by removing the screw(s) that attach the throttle or choke shutter to the shaft inside the air horn.

Use carb. tool # 670377

32

6. Remove the primer bulb (if equipped) by grasping it with a pliers and pulling and twisting out of the body. Remove the retainer by prying and lifting it out with a screwdriver. Do not re-use the old bulb or retainer (diag. 33). 7. Some Tecumseh float style carburetors have a damper spring which is installed as shown. (diag. 34)

33

34 17

8. Remove all welch plugs if cleaning the carburetor. Secure the carburetor in a vise equipped with protective jaws. Use a small chisel sharpened to a 1/8" (3.175 mm) wide wedge point. Drive the chisel into the plug to pierce the metal, then push down on the chisel to pry the plug out of the hole (diag. 35).

NOTE: DO NOT REMOVE ANY BALL OR CUP PLUGS (diag. 37).

SMALL CHISEL PIERCE PLUG WITH TIP PRY OUT PLUG DO NOT ALLOW CHISEL POINT TO STRIKE CARBURETOR BODY OR CHANNEL REDUCER

WELCH PLUG TO BE REMOVED ABOUT 1/8" (3.175 mm) WIDE

SMALL CHISEL

EXTENTED PRIME FUEL PASSAGE (SUPPLIES FUEL AFTER ENGINE START)

9. Note the direction of the inlet fitting. If necessary the inlet fitting can be removed. (See page 24).

10. The main nozzle on Series 8 and Series 9 carburetors can be removed by pressing the tube outward from the venturi thru the center leg. This nozzle is non-metallic and has an "O" ring seal on the top and bottom end of the tube. Do not remove a main nozzle that is made of brass from any Tecumseh carburetor. These are pressed in at the factory to a specific depth. When removing the nozzle, the top "O" ring may not come out with the tube. The "O" ring must be removed and placed on the nozzle before it is placed back into the center leg or it will not seal properly. (diag. 38) 11. Servicing the standard series eleven and bridged model. When servicing the series eleven DO NOT soak it in dipping type carburetor cleaners, use only spray cleaner or standard solvent tank cleaners. Proper cleaning requires removal of both welch plugs and cleaning of the restictor(s) as equipped. The standard series eleven has one restictor in the extended prime well as shown (diag. 36). The Bridged series eleven has an additional restrictor on the idle leg of the carburetor as shown (diag. 37). Both are cleaned using spray carburetor cleaner, compressed air and soft tag wire no larger than .012 inch (.3mm) or damage will occur.

35

EXTENDED PRIME FUEL CHAMBER RESTRICTOR WELCH PLUG

WELCH PLUG

MAIN JET

FUEL INLET

36

DO NOT REMOVE PLUGS BRASS OR BALL PLUG

BALL PLUG OR RESTRICTOR HOLE IF BRIDGED SERIES 11

IDLE FUEL PASSAGE REDUCTION ROD INSIDE NOT MACHINED ON SERIES 11

37 NOT USED ON SERIES 7 OR VECTOR CARBS. "O" RING ON TOP OF STEP (IN GROOVE)

"O" RING IN GROOVE "O" RING

38

SERVICE MAIN NOZZLE REUSABLE

The main nozzle on some Walbro carburetors are removable for service. If you remove it, a service nozzle with the under cut fuel passage must be installed or problems will occur (diag. 39).

UNDERCUT ANNULAR GROVE

ORIGINAL MAIN NOZZLE DO NOT REUSE

18

39

Diaphragm Carburetors 1. Remove the screws holding the diaphragm cover on. 2. Remove the cover, gaskets, and diaphragm noting or marking the sequence or location to aid in reassembly. NOTE: If a "F" designation on the choke end of the carburetor is present, place the diaphragm on first, then the gasket and cover. If no "F" is present, the gasket goes first. 3. Note or mark the high and low mixture adjustment screws. Remove the screw assemblies. 4. Note or mark the action of the choke and throttle shutters and the hook points of the choke or throttle return spring or seal retainer springs located on the top of the choke or throttle shaft. Remove the throttle shutter, throttle shaft, choke shutter, springs and choke shaft by removing the screw or screws that attach the throttle or choke shutter to the shaft inside the air horn. 5. Use a 9/32" (7.144 mm) thin wall socket to unscrew and remove the inlet needle and seat assembly (diag. 40). 6. Note and mark the direction of the inlet fitting. If necessary the inlet fitting can be removed by pulling with a pliers or vise. Some diaphragm carburetors have a strainer as an integral part of the fuel fitting. If the strainer is lacquered or cannot be cleaned, the fitting must be replaced. 7. Remove all welch plugs if cleaning the carburetor. Secure the carburetor in a vise equipped with protective jaws. Use a small chisel sharpened to a 1/8" (3.175 mm) wide wedge point. Drive the chisel into the plug to pierce the metal, then push down on the chisel to pry the plug out of the hole. NOTE: DO NOT REMOVE ANY BALL OR CUP PLUGS.

"F" DESIGNATION

"F" DIAPHRAGM FIRST NOT GASKET

40

CARBURETOR FITTING VALVE CLOSED ATMOSPHERIC VENT

VALVE OPEN DIAPHRAGM FILTER AIR BLEED VALVE CLOSED

VALVE OPEN

PULSE LINE TO CRANKCASE

FUEL SUPPLY

ê á á

CRANKCASE PRESSURE ATMOSPHERIC PRESSURE ACTING ON DAMPING DIAPHRAGM FUEL FLOW

ê á

CRANKCASE SUCTION AND FLOW DIRECTION ATMOSPHERIC PRESSURE ACTING ON DAMPING DIAPHRAGM

á ê

SUCTION FUEL FLOW DIRECTION ATMOSPHERIC PRESSURE CAUSED FUEL FLOW

41

IMPULSE FUEL PUMP To service, disassemble the pump by removing the four (4) screws. Clean all parts with a solvent and install a new kit which consists of a coil spring, gaskets and diaphragms (diag. 41 & 42).

FLOAT ADJUSTING PROCEDURE All Tecumseh carburetors with an adjustable float require a specific float height adjustment to achieve proper operation and easy engine starts. To check the float height, hold the carburetor in an upside down position. Remove the bowl nut, float bowl, and "O" ring. Place the Tecumseh carburetor tool #670377 with flat dimensions of 11/64" (4.36 mm) across the top of the carburetor casting on the opposite side and parallel to the float hinge pin (diag. 43). The float must just touch the carb tool. If the float is too high or too low, adjust the height by bending the float tab accordingly. If the required adjustment is minor, the tab adjustments may be made without removing the float and carefully inserting a small bladed screwdriver to bend the tab. Float sticking can occur due to fuel deposits or when the fuel tank is filled for the first time, this condition can be quickly corrected by loosening the carburetor bowl nut one full turn. Turn the bowl 1/4 turn in either direction, then return the bowl to its original position and tighten the bowl nut.

OLD STYLE

NEW STYLE

42

Carb. tool # 670377

RIM

43 19

INSPECTION After careful disassembly of the carburetor and the removal of all non metallic parts, the carburetor body and all other metallic parts should be cleaned with solvent, or commercial carburetor cleaner, no longer than 30 minutes. Use compressed air and soft tag wire to clean internal carburetor passages. To do a proper cleaning job, the welch plugs must be removed to expose the drilled passages. NOTE: The nylon check balls used in some diaphragm carburetors are not serviceable. Nylon can be damaged if subjected to harsh cleaners for prolonged periods. Throttle and Choke Examine the throttle lever and shaft, choke lever and shaft, and carburetor body at the bearing points and holes into which the linkage is fastened, and replace if worn or damaged. Any looseness in these areas can cause dirt to enter the engine and cause premature wear. If dust seals are present, these should be positioned next to the carburetor body.

Idle and High Speed Mixture Adjusting Screw RETAINER NUT "O" RING BRASS WASHER (used to protect the "O" ring from the spring) SPRING

Examine the idle mixture needle tip and tapered surface for damage. The tip and tapered surface of the needle must not show any wear or damage at all. If either is worn or damaged, replace the adjusting needle. Tension is maintained on the screw with a coil spring. Examine and replace the “O” ring seal if damaged (diag. 44).

HIGH SPEED ADJUSTMENT SCREW

44

Examine the tapered surface of the high speed mixture needle. If the tapered surface is damaged or shows wear, replace the needle (non-emissioned). Some Tecumseh carburetors use serviceable jet main nozzles. These are identified as being non-metallic. Fuel Bowl Retaining Nut

FUELMETERING PORT

IDLE FUEL TRANSFER PASSAGE

FUEL-INLET PORTS

ONE-HOLE TYPE TW0-HOLE TYPE 45 The retaining nut contains the transfer passage or metering jet through which fuel is delivered to the high speed and idle circuit of the carburetor. If a problem occurs with the idle circuit, examine the small fuel passage in the annular groove in the retaining (metering) nut. This passage must be clean for the proper transfer of fuel into the idle metering circuit. Torque retaining nut to 50 in. lbs. (5.65 Nm) when reinstalling.

There are two different types of bowl nuts that are used on adjustable main, float style carburetors. One type has one fuel metering port at the bottom of the nut, and the other has two fuel inlet ports at the bottom of the nut. This difference relates to calibration changes to the carburetor and is dependent on the application (diag. 45). NOTE: DO NOT INTERCHANGE BOWL NUTS. The fuel inlet ports must be free of any debris to allow proper fuel flow. Fuel Bowl, Float, Needle and Seat The float bowl must be free of dirt and corrosion. Clean with solvent or carburetor cleaner. Examine the float for damage. Check the float hinge bearing surfaces for wear, as well as the tab that contacts the inlet needle. Replace any damaged or worn parts. The needle and seat should be replaced if any fuel delivery problems are experienced (flooding or starvation). Sealing problems with the inlet needle seat may not be visible, so replacement is recommended. Diaphragms, Pulse Pumps, and Primer Bulbs Inspect diaphragms, gaskets, and primer bulbs for cracks, tears, hardness or brittleness. Replace if necessary. 20

ASSEMBLY Welch Plugs To install a new welch plug after cleaning the carburetor, secure the carburetor in a vise equipped with protective jaws. Place the welch plug into the receptacle with the raised portion up. With a punch equal to, or greater than the size of the plug, merely flatten the plug. Do not dent or drive the center of the plug below the top surface of the carburetor. After installation of the welch plug, seal the outer diameter with finger nail polish or equivalent (diag. 46).

FLAT END PUNCH NEW WELCH PLUG

SAME OR LARGER DIAMETER OF PLUG

46

SERIES 1, 6, 8, 9, 10 THROTTLE PLATE

THROTTLE LEVER TWELVE O'CLOCK POSITION

Throttle Shaft and Plate When reassembling, it is important that the lines or lettering on the throttle plate are facing out when in the closed position. Position throttle plate with two lines at 12 and 3 o’clock. If the throttle plate has only one line, the line should be positioned in the 12 o’clock position on Series 1, 6, 8, and 9 carburetors, and positioned in the 3 o’clock position on Series 3 and 4 carburetors (diag. 47 & 48).

47 SERIES 3 AND 4 THREE O'CLOCK POSITION

Test the operation of the throttle and return spring (if equipped). If binding occurs, correct by loosening screws and repositioning throttle plate. Always use a new screw(s) when reinstalling the throttle shutter (Tecumseh screws are treated with dry-type adhesive to secure them in place).

48

NOTE: NEVER REUSE OLD SCREWS. Choke Shaft and Plate The choke plate is inserted into the air horn of the carburetor in such a position that the flat surface of the choke is down. Choke plates will operate in either direction. Make sure it is assembled properly for the engine. Test the operation of the choke and return spring function if equipped (diag. 49).

CHOKE PLATE

Always use a new screw(s) when reinstalling the choke shutter as the screws are treated with dry-type adhesive to secure them in place. NOTE: NEVER REUSE OLD SCREWS. The choke shaft and plate must be in the closed position prior to tightening the screws. Hard starting may be due to insufficient choking action because of a misaligned choke plate. Correct by readjusting the choke plate to close completely. Note the cut-out position of choke shutter if applicable.

FLAT DOWN

49

CHOKE PLATE

Fuel Inlet Fitting Support the carburetor body with a wood block to avoid damage to other parts. Use a bench vise or press to install the fitting squarely. Insert the tip into the carburetor body, coat the exposed portion of the shank with Loctite grade A, then press it in until the shoulder contacts the carburetor body.

FLAT SIDE DOWN

50 21

High and Low Speed Adjusting Screw, Main Nozzle When reassembling, position the coil spring on the adjusting screws, followed by the small brass washer and the “O” ring seal. Turn the high speed adjustment screw in approximately one turn into the bowl retainer nut to make an assembly (diag. 51). On 2-7 hp. engines that use carburetors which have the metering rod in the idle circuit (carburetor should rattle when shaking), make certain that the idle adjustment screw is installed when the carburetor is in an upright position or the needle will damage the metering rod, adjustment screw and carburetor casting.

RETAINER NUT

SPRING TORQUE NUT TO 50 IN. LBS. (5.65 Nm)

On float type carburetors, make sure the seat cavity is clean. Moisten the seat with oil and insert the seat with the grooved side down and away from the inlet needle. Press the seat into the cavity using the Tecumseh carburetor tool #670377 making sure it is firmly seated (diag. 52). The inlet needle hooks onto the float tab by means of a spring clip. To prevent binding, the long, straight end of the clip should face the air intake end of the carburetor as shown (diag. 53). On diaphragm carburetors the inlet needle and seat assembly are installed by using a socket to tighten the assembly until seated.

CARB TOOL #670377 PRESS IN UNTIL SEAT RESTS ON BODY SHOULDER INLET NEEDLE MAKES CONTACT HERE

SEAT

INSERT THIS FACE FIRST

52

LONG END OF CLIP

CLIP OPEN END OF CLIP THROTTLE END

Needle and Seat Pop-Off Test To test the pop-off pressure, remove the carburetor from the engine. Be sure to drain any fuel into an approved container. Invert the carburetor and remove the float bowl. This test is best performed when the carburetor is placed upside down and level in a soft jawed vice. Lift the float and needle assembly off of the seat in order to place a drop of WD-40 on the tip of the needle or on the seat surface. Reposition the float and needle assembly. Using the Tecumseh Leak Tester part # 670340, connect the high pressure regulator to the low pressure regulator and attach the clear low pressure air line to the carburetor fuel inlet. Apply approximately 5-6 psi of compressed air, close the gate valve and disconnect the low pressure guage from the high pressure guage. Monitor the low pressure guage to make sure the needle shouldn't drop below 1.5 psi before 1 minute of time elapses. If the minimum of 1.5 psi cannot be maintained for this period of time, then replacement of the needle and seat is required. Float Installation

HIGH SPEED ADJUSTMENT SCREW

51

Some carburetors are of the fixed main type and would not have a high speed adjusting screw. Inlet Needle and Seat

"O" RING BRASS WASHER

CHOKE END

53

INLET NEEDLE FLOAT SPRING

HINGE PIN FLOAT

54

Reinstall the inlet needle and float into the carburetor. The long end of the spring or clip on the inlet needle must point toward the air intake end of the carburetor. If a float dampening spring is used, reassemble using the following steps (diag. 54). 1. Place the float upside down. 2. Position the spring on the float with the long end around and to the back side of the float’s center back tang. The ends must point toward the choke end of the carburetor. Hook the inlet needle clip on the inside float tang so the clip end points to the choke end of the carburetor (diag. 54). 3. Place the float, float spring, clip and inlet needle in position between the hinge legs of the carburetor. As the float assembly nears the hinge legs, wind the outside end of the spring so it goes to the outside of the leg (counterclockwise looking from the choke end). 22

4. Install the hinge pin from the opposite hinge leg. The bowl gasket must be positioned over the end of the spring (diag. 55). GASKET GOES OVER SPRING

5. Set the proper float height. See “Float Adjusting Procedure” in this chapter.

CHOKE END OF CARBURETOR

Diaphragm Assembly The rivet head on the diaphragm must always face toward the inlet needle valve. On carburetors with an “F” cast into the carburetor flange as illustrated, the diaphragm goes next to the carburetor body. Other diaphragm carburetors have the gasket located between the diaphragm and carburetor body. Install the cover retaining screws and tighten (diag. 56).

ENDS OF SPRING POINT TOWARD CHOKE END OF CARBURETOR

55

Fuel Bowl And Bowl Nut Whenever a carburetor bowl is removed for service, the fuel bowl “O” ring must be replaced. For easier installation, lubricate the “O” ring with a small amount oil. Install the float bowl by placing the detent portion opposite of the hinge pin. Make sure the deepest end of the bowl is opposite of the inlet needle. The bowl has a small dimple located in the deepest part. The purpose of this dimple is to minimize the chances of the float sticking to the bottom of the bowl caused by stale fuel (diag. 57). On some fixed jet (non-adjustable) and adjustable carburetors, a fibered washer is required between the carburetor bowl and the bowl retaining nut.

GASKET

RIDGE AND RIVET HEAD UP

RIDGE AND RIVET HEAD UP

GASKET

56

DETENT

Occasionally, on engines equipped with the dual system carburetor, some rich starting conditions have occurred when the engine is warm. This condition can be corrected by inserting a non-metallic spacer in the center leg of the carburetor, as shown (part # 632158). This spacer is designed to reduce the amount of prime charge in the main nozzle area for better starting under warm engine conditions. It can only be used on Dual System carburetors and does not lean out the carburetor mixture. (diag. 58) This spacer must be reinstalled if originally equipped in the carburetor.

57

Impulse Fuel Pump The diaphragms must be installed against the center body with the gaskets against the outside covers. The parts are designed so they cannot be misassembled without damage (diag. 58).

NON-METALLIC SPACER

58

To test the unit, assemble the carburetor to the engine, leaving the fuel line from the pump off. Use a different fuel tank remotely placed above the carburetor to provide gravity fuel flow to the carburetor inlet to run the engine while testing the pump. Make sure fuel is available in both fuel tanks and that the original fuel tank's fuel line is connected to the fuel pump inlet. Place the pump outlet line in a proper draining receptacle. With the pulse line connected from the engine crankcase to the pump and the engine running, a definite fuel flow should result at the pump outlet. If the flow is erratic or intermittent, the pump needs repair or replacement.

23

Primer Bulb To install, start the retainer and bulb into the casting with the retainer tabs pointed out. Firmly push the bulb and retainer into position using a 3/4'’ (19.05 mm) deep well socket (diag. 59). Final Checks Before reinstalling a newly overhauled carburetor, pre-set the main mixture adjustment screw, the idle mixture adjustment screw and the idle speed adjustment screw. See “Pre-sets and Adjustments” in this chapter. 59

STANDARD SERVICE CARBURETORS Tecumseh supplies some replacement carburetors on which parts from the old carburetors can be reused or new parts added. This Standard Service Carburetor helps to reduce dealer inventories. Standard Service Carburetors are built in both float and diaphragm versions. The parts from the original carburetor that are necessary to make a standard service carburetor are: choke shaft, shutter and spring, throttle lever and spring, fuel fitting, idle adjustment screw and spring. If any or all of these old parts are worn or damaged, replace each part with a new service part to assure proper function and prevent engine damage. Use the diagrams on the next page as a guide to facilitate the correct installation of parts (diag. 61 & 62).

Fuel Fitting NOTE: MOST SERVICE CARBURETORS ARE MARKED “SVC CARB NF” IN THE PRICE LIST. THIS MEANS THAT THE CARBURETOR COMES WITH NO FUEL FITTING. Use the parts manual to obtain the same fuel inlet fitting that was installed in the original carburetor. Install the fuel fitting in the new carburetor body in the same position as on the original carburetor. Support the carburetor body with a wood block to avoid damage to other parts. Use a bench vise or press to install the fitting squarely. Press it in until it bottoms out. NOTE: PRESS FUEL FITTING IN SQUARELY USING CAUTION SO THAT THE CARBURETOR BODY IS NOT DAMAGED.

Inlet Fuel Fitting To remove a leaking or damaged fuel inlet fitting, use a 1/4"(6 mm) bolt, 1/4" (6 mm) nut and 1/4" (6 mm) washer, along with a 1/2" (12 mm) nut. Use a pliers or vise to remove the plastic part of the inlet fitting. Tap the inside of the remaining metal portion of the fitting using a 1/4"- 20 (6 mm) tap. Place a 1/2" (12 mm) nut over the fuel fitting (it may be necessary to guide one side of the nut to seat it squarely to the carburetor). Next thread the 1/4" (6 mm) nut on the bolt until it contacts the shank, add the washer, and thread the bolt into the fitting until snug. Tighten the 1/4"- 20 (6 mm) nut until the fitting is removed. (diag. 60)

60

Choke Shaft NOTE: Never reuse choke or throttle shutter screws, always replace with new Tecumseh service screws. Remove the choke shutter screw from the original carburetor and remove the choke shaft. Observe the position of the ends of the choke return spring if one is present. Also observe the position of the cut-out and/or holes in choke shutter. Some chokes turn clockwise and some turn counterclockwise, note the position of the choke shaft prior to removal from the old carburetor. If a choke stop spring is present on the new carburetor and is not used on the old carburetor, cut it off with a side cutter or pull it out using a pliers. Test the action of choke shaft to make sure it moves freely and easily and does not bind in either open or closed position. If binding occurs, loosen the shutter screw; reposition the shutter and tighten the screw. 24

Throttle Lever Remove the throttle lever and spring and file off the peened end of the throttle shaft until the lever can be removed. Install the throttle spring and lever on the new carburetor with the self-tapping screw furnished. If dust seals are furnished, install them under the return spring.

Idle Speed Adjustment Screw Remove the screw assembly from the original carburetor and install it in the new carburetor. Turn it in until it contacts the throttle lever. Then an additional 1-1/2 turns for a static setting.

Final Checks Consult the service section under “Pre-sets and Adjustments” and follow the adjustment procedures before placing the carburetor on the engine. FLOAT TYPE CARBURETOR CHOKE SHAFT IDLE CRACK SCREW AND SPRING

DIAPHRAGM TYPE CARBURETOR THROTTLE LEVER AND SHAFT

SELF TAPPING SCREW

CHOKE LEVER AND SHAFT

LEVER SPRING

SPRING SPRING WASHER FELT SEAL

WASHER

WASHER FELT SEAL

FELT SEAL

THROTTLE SHAFT THROTTLE SHUTTER SHUTTER SCREW

CHOKE STOP SPRING

IDLE ADJUSTMENT SCREW

SHUTTER SHANK

SEAL WASHER

SCREW FUEL FITTING

FUEL INLET

CHOKE SHUTTER

SPRING

"O" RING

SHUTTER SCREW

SEAT AND CLIP INLET NEEDLE

LOW SPEED ADJUSTMENT SCREW

SPRING CLIP FLOAT FLOAT SHAFT

HIGH SPEED ADJUSTMENT SCREW

DIAPHRAGM DIAPHRAGM GASKET DIAPHRAGM COVER

FLOAT BOWL

BOWL NUT WASHER

PRIMER FITTING

DIAPHRAGM COVER SCREW

HIGH SPEED BOWL NUT

61

62

25

CHAPTER 4 GOVERNORS AND LINKAGE GENERAL INFORMATION This chapter includes governor assembly and linkage illustrations to aid in governor or speed control assembly. Tecumseh 4 cycle engines are equipped with mechanical type governors. The governor’s function is to maintain a constant R.P.M. setting when engine loads are added or taken away. Mechanical type governors are driven off the engine’s camshaft gear. Changes in engine R.P.M. cause the governor to move the solid link that is connected from the governor lever to the throttle in the carburetor. The throttle is opened when the engine R.P.M. drops and closes as the engine load is removed.

OPERATION

SPRING

As the speed of the engine increases, the governor weights (on the governor gear) move outward by centrifugal force. The shape of the governor weights force the governor spool to lift. The governor rod maintains contact with the governor spool due to the governor spring tension. As the spool rises, the governor rod rotates, causing the attached outer governor lever to pull the solid link and close the throttle opening. When the engine speed decreases, the lower centrifugal force allows the governor weights to be pulled in by the governor spring. As the spool lowers, the governor rod rotates and the solid link pushes the throttle to a more open position (diag. 1).

THROTTLE

GOVERNOR SHAFT

GOVERNOR SPOOL

WEIGHTS GOVERNOR GEAR

1

INTERNAL COMPONENTS (VARIOUS STYLES) RETAINING RING

RETAINING RING SPOOL

SHAFT

SPOOL SPOOL

RETAINING RING GEAR ASSY. (GOV.)

WASHER

UPSET NO RETAINING RING SHAFT

WASHER RETAINING RING GEAR ASSY. (GOV.)

SPOOL SPOOL

WASHER

WASHER GEAR ASSY. (GOV.)

RETAINING RING

SPACER

GEAR

ASSY.

SHAFT

GEAR ASSY. (GOV.)

(GOV)

BRACKET

WASHER

SHAFT

ROD ASSY (GOV.)

WASHER

SHAFT SCREWS

TVS STANDARD

2

TVS UPSET

3

MEDIUM FRAME

4

HORIZONTAL

5

LEV

6

TROUBLESHOOTING Engine problems where the governor is suspected to be the cause, may actually be the result of other engine system problems. Hunting (engine R.P.M. surging up and down) indicates that the engine is incapable of maintaining a constant R.P.M. with or without an engine load. Engine overspeeding (either with or without throttle movement) must be corrected immediately before serious engine damage occurs. Use the following procedure to diagnose a suspected governor problems.

26

ENGINE OVERSPEEDING 1. If the engine runs wide open (faster than normal), shut the engine off immediately. 2. Check the condition of the external governor shaft, linkage, governor spring, and speed control assembly for breakage, stretching or binding. Correct or replace binding or damaged parts. 3. Follow the governor adjustment procedure and reset the governor - see "Service" in this chapter. 4. Run the engine. Be ready to shut the engine off if an overspeed problem still exists. If the problem persists, the engine will require disassembly to inspect the governor gear assembly for damage, binding, or wear. 5. See Chapter 9 under "Disassembly Procedure" to disassemble the engine. 6. Remove the governor gear assembly. Repair or replace as necessary.

ENGINE SURGING 1. Try to stabilize the engine R.P.M. by holding steady the solid link between the governor arm and the carburetor throttle, using a pliers or fingers. 2. If the engine R.P.M. stabilizes, the governor or governor adjustment should be checked. See "Service" governor adjustment procedure in this chapter. If the engine R.P.M. does not stabilize, the engine will require additional checks, see Chapter 9 under "Troubleshooting". 3. If the problem persists after the governor adjustment, check the engine R.P.M. found on microfiche card # 30. The R.P.M. settings are critical. If the R.P.M. setting for high and low speed are within specification and a slight surge is experienced, increasing the engine idle R.P.M. setting slightly may eliminate this condition. 4. Check the governor shaft or linkages for binding, wear, or improper hookup. Check the governor spring for adequate tension. Repair or replace as necessary.

SERVICE

Ý

GOVERNOR ADJUSTMENT

PUSH LEVER TO OPEN THROTTLE

With the engine stopped, loosen the screw holding the governor clamp on the governor lever. Rotate the clamp in a direction that will force the throttle shaft open and allow the governor follower arm to rest on the governor spool. Push the governor lever connected to the throttle to the wide open throttle position. Hold the lever and clamp in this position while tightening the screw (diag. 7).

Ú GOVERNOR SHAFT

GOVERNOR ADJUSTMENT PROCEDURE FOR SHORT BLOCK INSTALLATIONS

GOVERNOR SPOOL GOVERNOR GEAR

7 Short block installation on 3-5 h.p. vertical shaft engines built prior to 1977 may require the governor clamp (tinnerman style) to be repositioned to work properly. The clamp must be removed from the governor rod and turned to the same position as the original engine. Hook the solid link and spring to the governor lever and position the clamp on the governor rod. Follow the above governor adjustment procedure to complete the short block governor set-up. Units built after 1977 use the normal governor set up procedure. (diag. 8)

Figure A Before 1977 production

VERTICAL

Figure B 1977 & Later production

8 27

GOVERNOR GEAR AND SHAFT SERVICE After the cylinder cover is removed from the engine, the governor spool, gear, or governor shaft can be removed. On older style governor assemblies, the retaining ring must be removed to allow the spool or gear to slide off the shaft. Newer style governor shafts (3 - 6.75 model engines) use an upset to hold the governor spool on. If the gear requires replacement, the governor shaft will have to be removed.

Governor Spool Replacement With Upset Style Governor Shaft The spool can be replaced without removing the governor shaft. Grip the original spool in a vise and use a twisting and pulling motion on the flange until the spool is free. Install the new spool by starting it on the shaft and then turning the flange over. This will allow the weights to hang in the proper position. Place the spool on a solid surface and push on the flange until the spool seats. The governor weights must be in position under the spool after installation. (diag. 9)

Governor Gear or Shaft Replacement, Upset Style Governor Shaft 1. Grip the original spool in a vise and use a twisting and pulling motion on the flange until the spool is free. 2. Clamp the shaft in a vise and pound gently on the flange with a wooden or plastic mallet to remove the shaft.

9

NOTE: DO NOT TWIST THE SHAFT WHEN REMOVING. THE SHAFT BOSS MAY BECOME ENLARGED, LEAVING THE NEW GOVERNOR SHAFT LOOSE AND CAUSING SEVERE DAMAGE. GEAR

3. To install a new shaft, first assemble the gear and washer on the shaft. Start the shaft into the hole with a few taps from a soft faced hammer. 4. Place the flange in a press with a solid piece supporting the area below the shaft boss. Press the shaft in until a shim, part # 670297 just becomes snug [.010 - .020 (.254 - .508 mm) clearance].

SHIM WASHER SHAFT BOSS

670297 (modified)

Governor Shaft Replacement, Retaining Ring Style 1. Remove the retaining ring, spool, gear assembly, and washers. 2. Clamp the shaft in a vise and pound gently on the flange with a wooden or plastic mallet to remove the shaft. NOTE: DO NOT TWIST THE SHAFT WHEN REMOVING. THE SHAFT BOSS MAY BECOME ENLARGED AND THE NEW GOVERNOR SHAFT WILL BE LOOSE AND MOVE. 3. Start the new shaft into the shaft boss by tapping with a soft faced hammer. 4. Refer to the chart at right for the proper shaft exposed length. Add a drop of red Loctite 271 and press the governor shaft to the proper depth using a press or a vise. Wipe the extra Loctite off after installation (diag. 11). 5. Reassemble the governor and install the retaining ring.

28

10 ENGINE MODEL

EXPOSED SHAFT LENGTH

ECH90 ECV100 H 30, 35 HS 40, 50 LAV 35 LEV (all) OHH (all) OVRM (all) TNT 100, 120 TVS (all)

Mounting flange to Top 1.319 - 1.334" (33.502 - 33.883 mm)

TVM (all) V 50, 60, 70 VH 50, 60, 70

Mounting flange to Top 1.581 - 1.596" (25.806 - 26.314 mm)

HH 100, 120 VH 100

Mounting flange to Top 1.016 - 1.036" (25.806 - 26.314 mm)

H 50, 60, 70 HH 60, 70 HHM80 HM 70, 80, 100

Mounting flange to Shoulder 1.283 - 1.293" (32.588 - 32.842 mm)

11

SPEED CONTROLS AND LINKAGE Many different types of speed controls and linkage are used for O.E.M. applications. Linkage attachment points are best recorded or marked prior to disassembly. This assures the correct placement during reassembly. On vertical shaft engines the solid link is always connected from the outermost hole in the governor lever to the throttle in the carburetor. The link with the governor spring attached is connected between the control lever and the lower hole in the governor lever. Horizontal engines use one location (non-adjustable) speed control brackets. Most vertical engines use an adjustable speed control bracket mounted above the carburetor. The ignition ground out switch, idle R.P.M. and high speed R.P.M. adjustment screws are located on the speed control bracket. Some models use the idle R.P.M. adjustment on the carburetor. Most vertical shaft engines must have the speed control bracket aligned when installing. To align the control bracket, use the following steps.

1. Loosen the two screws on the top of the panel.

LOOSEN TO ADJUST

WIRE HOLE

2. Move the control lever to full wide open throttle position and install a wire or aligning pin through the hole in the top of the panel, the hole in the choke actuating lever, and the hole in the choke (diag. 12). 3. With the components aligned, tighten the two screws on the control panel.

SNAP IN "STYLE SPEED CONTROL" This style of speed control is used on 3 - 6.75 model rotary mower engines and is adjusted by two bendable tabs. Use the speed adjustment tool (part # 670326) as illustrated in diag.13 to adjust engine speed. To adjust high speed, move the speed control lever to the high speed position and align the high speed pin holes. Place the adjustment tool on the high speed tab and move the tab to achieve the correct engine speed. Move the speed control lever to the low speed position, place the adjustment tool on the low speed tab and bend to either increase or decrease to the correct speed.

CONTROL LEVER

12 LOW SPEED TAB

HIGH SPEED TAB

HIGH SPEED PIN POSITION

Þ

The following pages illustrate common linkage attachment. Whenever the carburetor or the governor linkage is removed or replaced, the engine R.P.M.'s should also be checked. Use microfiche card #30 or the computer parts look-up system for the correct R.P.M. settings for the engine model and specification.

DECREASE

Þ

INCREASE TOOL 670326

13

29

ADJUSTING RPM ON MEDIUM FRAME VERTICAL SPEED CONTROL This speed control is adjusted by aligning the slot in the speed control lever with the alignment hole on the mounting bracket. Place a pin through the two holes, place the equipment throttle control to the wide open position, hook the bowden cable end in the control as shown, and tighten the cable housing clamp. In this position, the gap of .040" - .070" (1.016 - 1.778 mm) should exist at the gap location as illustrated. This will assure that the carburetor will go into full choke when the control is placed in the start position.

GOVERNED IDLE SPEED SCREW HIGH SPEED ADJUSTMENT TAB

GAP OF .040 - .070 (1.016 - 1.778 mm)

HIGH SPEED PIN POSITION TOOL 670326

Þ

DECREASE

Þ

INCREASE

14

ADJUSTING GOVERNED/NON-GOVERNED With the engine running at its lowest speed, set the governed idle at the designated RPM by adjusting the governed idle screw or bending the idle tab. Next set the non-governed idle by pushing the bottom of the governor lever away from the control brackets so the throttle lever contacts the idle speed crack screw (on the carburetor). Hold the lever in this position and turn the crack screw to 600 RPM below the governed idle speed. This setting prevents the throttle plate from closing off when going from high speed RPM to low speed RPM. If improperly adjusted, the engine could experience an over lean condition. The idle speed is adjusted by turning the idle speed screw clockwise to increase engine R.P.M. and counter-clockwise to decrease R.P.M. Use tool part # 670326 to adjust the high speed engine R.P.M. Place the slotted end of the tool onto the adjustment tab and bend the tab to the left (toward the spark plug end) to increase engine R.P.M. (diag. 14). NOTE: Some engines use nylon bushings on the throttle and choke linkage hook-up points to extend the life of the linkage and to enhance the stability of the governor system. Make sure they are in good condition and in place.

ADJUSTING RPM ON MEDIUM FRAME VERTICAL (up/down speed control) To adjust the high speed RPM on Medium Frame Vertical engines, move the control lever to the high speed pin position (align high speed pin holes in the speed control bracket). Place the slot on the straight end of tool (number 670326) onto the high speed adjustment tab as pictured. Rotate the bent end of the tool counterclockwise to increase RPM and clockwise to decrease RPM. (diag. 15).

30

HIGH SPEED ADJUSTMENT TAB

.040 - .070 (1.016 - 1.778 mm) GAP LOCATION

BEND AREA

CHOKE ADJUSTING TAB CONTROL LEVER HIGH SPEED PIN POSITION DECREASE

GOVERNED IDLE ADJUSTING SCREW

INCREASE TOOL 670326

15

HORIZONTAL SHAFT ENGINES IDLE SPEED CRACK SCREW

IDLE SPEED CRACK SCREW

HIGH SPEED RPM ADJUSTMENT SCREW

HIGH SPEED RPM ADJUSTMENT SCREW

HORIZONTAL LIGHTWEIGHT

16

LIGHTWEIGHT R.V. TYPE

17

IDLE SPEED CRACK SCREW

HIGH SPEED RPM ADJUSTMENT SCREW

IDLE MIXTURE SCREW

MAIN MIXTURE SCREW

SMALL FRAME

IDLE SPEED CRACK SCREW

HIGH SPEED RPM ADJUSTMENT SCREW

IDLE SPEED CRACK SCREW

HORIZONTAL MEDIUM FRAME

18

HIGH SPEED RPM ADJUSTMENT SCREW

19

CONSTANT SPEED APPLICATIONS

20 31

HORIZONTAL SHAFT ENGINES (CONTINUED) HIGH SPEED RPM ADJUSTMENT SCREW

IDLE SPEED SCREW IDLE SPEED CRACK SCREW

IDLE MIXTURE SCREW

HORIZONTAL MEDIUM FRAME

MAIN MIXTURE SCREW

IDLE MIXTURE SCREW

HMSK80-100

21

22

IDLE SPEED CRACK SCREW

HIGH SPEED RPM ADJUSTMENT SCREW

MEDIUM FRAME

BEND LOOP OPEN OR CLOSED TO ATTAIN OPERATING RPM'S

23

TO INCREASE SPEED - CLOSE LOOP TO DECREASE SPEED - SPREAD LOOP

IDLE SPEED CRACK SCREW

MAIN MIXTURE SCREW

SNOW KING ENGINES 32

24

SNOW KING ENGINES

25

VERTICAL SHAFT ENGINES HIGH SPEED ADJUSTMENT SCREW

BEND Ó TO INCREASE SPEED BEND Ô TO DECREASE SPEED

IDLE SPEED CRACK SCREW

VERTICAL SHAFT ENGINES

26

TNT 100 VERTICAL ENGINES

TVS 115/LEV ENGINE SPEED CONTROL

27

28

IDLE SPEED CRACK SCREW

IDLE MIXTURE SCREW

TVXL 220 WITH HORIZONTAL SPEED CONTROL 29

STANDARD TVM ENGINE WITHOUT GOVERNOR OVERRIDE 30 33

GOVERNOR OVERRIDE SYSTEM FOR TVM170, 195 AND 220 ENGINES This system will be found starting on 1985 production models, and will not retrofit onto older engines. It is designed to allow the governor to regulate the low and high speeds of the engine. The high speed is adjusted at the top screw of the override lever; to increase R.P.M. turn the screw out (counterclockwise), to decrease R.P.M. turn the screw in (clockwise). The low speed is adjusted at the bottom screw of the override lever; to increase R.P.M. turn the screw in or clockwise, to decrease R.P.M. turn the screw out or counterclockwise (diag. 31).

MAIN MIXTURE SCREW HIGH SPEED ADJUSTMENT SCREW

GOVERNED / NON-GOVERNED IDLE

LOW SPEED ADJUSTMENT SCREW

TVM ENGINES WITH GOVERNOR OVERRIDE 31 With the engine throttle set at its lowest speed, set the governed idle at the designated RPM by bending the idle RPM tab or adjusting a screw. Next set the non-governed idle by pushing the bottom of the governor lever away from the control brackets, so the throttle lever contacts the idle speed screw. Hold the lever in this position and turn the idle adjustment screw clockwise to increase or counterclockwise to decrease engine idle speed. The setting on the carburetor screw should be set 600 RPM below the governed idle setting. This setting prevents the throttle plate from closing when going from high speed RPM to low speed RPM. If improperly adjusted, the engine could experience an over lead condition.

34

CHAPTER 5 REWIND STARTERS GENERAL INFORMATION Rewind starters used on vertical shaft Tecumseh engines are top mount horizontal pull style or side mount vertical pull style. Horizontal shaft engines use side mounted starters which can be mounted to pull either vertically or horizontally. All rewind starters except the vertical pull style turn the engine over by engaging a dog(s) into the starter cup attached to the engine flywheel. The vertical pull starter engages the starter gear into the ring gear of the flywheel to turn the engine over. All starters are spring loaded to retract the dog(s) or starter gear when the engine speed exceeds the turning speed of the starter.

OPERATION As the starter rope is pulled, the starter pulley rotates on the center pin. The starter dog(s) is pinned or pocketed in the pulley hub and extends outward when the pulley's rotation forces the starter dog(s) to contact the ears on the retainer. The retainer ears act as a ramp to fully extend the starter dog(s). The fully extended starter dog(s) locks in contact with notches in the starter cup. When the engine fires and the rotational speed of the starter cup exceeds the starter pulley, the starter dog(s) disengages from the starter cup. The starter dog spring(s) returns the starter dog(s) to the disengaged position. The recoil spring turns the starter pulley in the opposite direction, retracting the starter rope until the handle contacts the stop.

COMPONENTS STARTER HOUSING

HANDLE

HANDLE

HOUSING

ROPE

SPRING & KEEPER

PULLEY AND REWIND SPRING ASSY. DOG SPRING STARTER DOG

PULLEY

WASHER RETAINER

DOG SPRING RETAINER BRAKE SPRING

BRAKE SPRING WASHER SPRING PIN

DOG BRAKE WASHER CAM DOG CENTER SCREW

1

2

SERVICE Starter related problems will require the starter to be removed from the engine to diagnose the cause. Visually inspect the starter dog(s), starter cup, retainer, springs, rope, washers, and the starter pulley for wear or breakage. Use one of the following procedures that applies to your application, to disassemble, repair, and assemble the starter. Always consult the Tecumseh Master Parts Manual for the correct replacement parts.

ROPE SERVICE Rope replacement should be done using the correct part number replacement rope or braided rope of the correct diameter and length. Consult the Tecumseh Master Parts Manual to obtain the correct part number, length, and size required. Use the following rope chart to convert a numbered rope to a fractional diameter for bulk rope use. # 4 1/2 rope

=

9/64" (3.572 mm) diameter

Part No. 730526

100' (30.48 meters) spool

# 5 rope

=

5/32" (3.964 mm) diameter

Part No. 730514

100' (30.48 meters) spool

# 6 rope

=

3/16" (4.762 mm) diameter

Part No. 730516

100' (30.48 meters) spool 35

Standard rope lengths LEFT-HAND KNOT

54" (16.5 meters) standard stamped steel starter 61" (18.6 meters) vertical pull - horizontal engagement type 65" (20 meters)

vertical pull - vertical engagement type

85" (26 meters)

extended handlebar rope start (compliance)

Check the old rope for the right length for the application. Some applications require longer lengths. The rope ends should be cauterized by burning with a match and wiping the rope end with a cloth while hot. Rope replacement can be done without the starter being disassembled on vertical pull starters that have "V" notches in the bracket. Use the following procedure for rope replacement.

3

1. Remove the starter assembly from the engine. 2. Turn the pulley until the staple in the pulley lines up with the "V" notch. Pry out the staple with a small screwdriver and remove the original rope (diag. 3). ONE PIECE ROPE RETAINER

3. Turn the pulley counterclockwise to fully wind the starter return spring until tight. Allow the pulley to unwind until the hole in the pulley lines up with the "V" notch. 4. Hold the pulley in this position and feed the new rope through the hole and tie a left-handed knot on the rope end. Make sure the rope and knot do not protrude from the knot cavity and bind the pulley rotation.

RETAINER REPLACEMENT (DIAGRAM 4) 1. Remove the starter handle if the retainer is a complete circle design. Remove the staple and old retainer.

4

STARTER HOUSING

HANDLE ROPE PULLEY AND REWIND SPRING ASSY.

2. Slide the rope retainer into the proper position and insert the staple using a pliers. 3. Install the starter handle and tie a left hand knot to secure the handle.

STYLIZED REWIND STARTER (TVS, HM, TVM, TVXL), AND STAMPED STEEL STARTER (HM, VM, TVM, TVXL)

DOG SPRING STARTER DOG WASHER RETAINER BRAKE SPRING WASHER SPRING PIN

5

Disassembly Procedure 1. After removing the rewind assembly from the engine blower housing, release the tension on the rewind spring. This can be done by removing the starter handle and carefully allowing the rope to unwind in the starter housing assembly. 2. Place a 1" (25 mm) deep well socket under the retainer. Set the rewind on a bench, supported on the socket. 3. Use a 5/16" (7.938 mm) or 1/4" (6.35 mm) (for stamped steel) roll pin punch to drive out the center pin. The stamped steel center pin is driven out from the top, inside the center hole. Move the punch around while driving the pin to help keep the pin straight.

6 36

CAUTION: THIS REWIND SPRING IS NOT SECURED IN A CANISTER. PULLEY BOSSES HOLD THE REWIND SPRING AND COVER, AND CAN BE EASILY DISLODGED DURING HANDLING. 4. Remove the brake spring, spring retainer, washers, and pulley assembly (diag. 7) NOTE: THE STARTER DOGS FACE OUT ON THE STAMPED STEEL STARTER AND THE DOGS FACE IN ON THE STYLIZED REWIND STARTER. 5. All components in need of service should be replaced.

Assembly Procedure NOTE: It is critical to support the starter on a deep well socket to prevent damage. 1. Reverse the disassembly procedure. The starter dogs with the dog springs must snap back to the center of the pulley (disengaged position). When the rope is pulled, the tabs on the retainer must be positioned so that they will force the starter dogs to engage the starter cup. (diag. 7 & 8)

LEFT-HAND KNOT

HANDLE INVERT AND SUPPORT THIS AREA

HANDLE INSERT ROPE

DOG SPRING

PULLEY AND REWIND SPRING ASSY.

2. Always replace the center spring pin with a new one upon reassembly. Place the two new plastic washers between the center leg of the starter and the retainer. New plastic washers are provided with a new center spring pin. Discard the old plastic washer. 3. Prior to reinstalling the new spring pin, invert the housing and support the center of the housing on a socket approximately 3/4" (19 mm). Drive the pin into the housing until 1/8" (3.1 mm) as shown. (diag. 7 & 8)

SPRING PIN 1/8" FROM TOP

STARTER HOUSING

WASHER

STARTER DOG

RETAINER

BRAKE SPRING

WASHER

SPRING PIN

7 INVERT AND SUPPORT THIS AREA

SPRING PIN 1/8" FROM TOP

STARTER HOUSING

NOTE: DO NOT DRIVE THE CENTER PIN IN TOO FAR. The retainer will bend and the starter dogs will not engage the starter cup. On the stamped steel starter the center pin should be driven in until it contacts the shoulder in the starter body. 4. Apply tension to the recoil spring by winding the pulley counterclockwise until it becomes tight, then allow the pulley to unwind until the hole in the pulley lines up with the rope eyelet in the starter housing. Install a knotted rope through the pulley and the eyelet and install the handle. A left-hand knot should be tied on the end of the rope to secure the handle.

HANDLE ROPE PULLEY AND REWIND SPRING ASSY. DOG SPRING STARTER DOG WASHER RETAINER BRAKE SPRING WASHER SPRING PIN

8

STYLIZED REWIND STARTER WITH PLASTIC RETAINER Disassembly Procedure 1. After removing the rewind assembly from the engine blower housing, remove the starter handle by first pulling a length of rope out using the handle, tying a temporary knot in the exposed rope, and either untying the knot in the handle or prying out the staple. 2. Untie the temporary knot and slowly allow the rope to fully retract into the starter housing and the recoil spring to fully unwind. 3. Remove the decal from the center of the starter housing.

4. Use a small Phillips screwdriver or similar tool to pry the retainer legs apart and lift out the retaining wedge (or steel clip on newer style starters). 5. Pinch the legs of the retainer together and pull on the head of the retainer to remove it from the housing. 6. Remove the pulley assembly from the recoil housing. 7. Repair or replace as necessary.

Assembly 1. If replacing the starter rope, see Step 8.

LEFT-HAND KNOT

RETAINING WEDGE (STEEL CLIP - NEW STYLE)

Recoil starters are under heavy tension. Extreme caution should be used when working with these parts and always wear safety glasses, leather gloves and a heavy, long sleeved shirt.

STARTER HOUSING

2. Install a new recoil spring/pulley assembly into the starter housing. 3. Replace or check that both starter dogs are in the pulley pockets and that the dog springs are hooked on the outer surface of the starter dog.

STARTER PULLEY SPRING & COVER

4. Pinch the two legs of the plastic retainer together and slightly push the retainer into the center shaft hole.

DOG SPRING

5. Rotate the retainer so the two tabs on the bottom of retainer contact the dog on the inward side so when the rope is pulled the retainer tabs cause the dogs to flair outward. Push the retainer in until the leg prongs pop out of the center shaft.

STARTER DOG

DOG RETAINER

6. Turn the starter over and snap the locking tab between the retainer legs, replace the top decal.

9

The service replacement retaining wedge is spring steel. 7. Apply tension to the recoil spring by winding the pulley counterclockwise until it becomes tight, then allow the pulley to unwind until the hole in the pulley lines up with the rope eyelet in the starter housing. Install a knotted rope through the pulley and the eyelet and install the handle. A left-hand knot should be tied on both ends of the rope to secure the handle and rope in pulley.

STANDARD STAMPED STEEL AND CAST ALUMINUM STARTER (HM, VM) Disassembly Procedure 1. Untie the knot in the rope and slowly release the spring tension. 2. Remove the retainer screw, retainer cup (cam dog on snow proof type), starter dog(s) and dog spring(s), and brake spring (diag. 10). 3. Turn the spring and keeper assembly to remove the pulley. Lift the pulley out of the starter housing. Replace all worn or damaged parts.

INVERT AND SUPPORT THIS AREA

REWIND SPRING AND KEEPER ASSY.

HANDLE

HANDLE INSERT

ROPE

PULLEY

Assembly Procedure

CAM DOG

1. Apply a light coat of NON-FREEZE grease to the spring before installing into the pulley. Install the pulley assembly into the starter housing.

WASHER

2. Install the brake spring, starter dog(s), and starter dog return spring(s). The starter dog spring(s) must hold the dog(s) in against the pulley. On Snow King engines the starter dog posts should be lubricated with S.A.E. 30 engine oil to prevent oxidation. 38

STARTER HOUSING

DOG SPRING STARTER DOG DOG RETAINER RETAINER SCREW BRAKE SPRING SPRING PIN

10

3. Replace the retainer cup (cam dog on snow proof starter) and retainer screw. Tighten to 65 - 75 in. lbs. Older models that use a 10 - 32 retainer screw can be replaced with a larger 12 - 28 screw (part # 590409A). Re-drill the screw hole using a 13/64" (4.35 mm) drill bit. The center screw torque on cast aluminum starters is 115 to 135 in. lbs (13 - 15 Nm) (diag. 11 & 12). 4. Add-on alternator starters must have the center tubular rivet replaced each time the tubular rivet is removed. The tubular rivet should be pressed to a depth of 1/4" (3.175 mm) from the top of the starter housing. Skip this step if not applicable. 5. Apply tension to the recoil spring by winding the pulley counterclockwise until it becomes tight, then allow the pulley to unwind until the hole in the pulley lines up with the rope eyelet in the starter housing. Install a knotted rope through the pulley and the eyelet and install the handle. A left-hand knot should be tied on the end of the rope to secure the handle. 6. If a centering pin is used, be sure to align with the crankshaft (bottom pin in center screw hole). Install nylon sleeve 1/8" (3.175 mm) onto pin. Position nylon sleeve in aligning recess in the crankshaft. START two mounting screws in blower housing 90o apart. With sleeve centered in crankshaft, gently push the starter in place, tighten the two mounting screws, insert and tighten the other two screws.

LEFT-HAND KNOT

HOUSING

HANDLE

SPRING & KEEPER ASSY.

PULLEY

BRAKE SPRING

DOG SPRING

RETAINER RETAINER SCREW CENTER PIN

11

HOUSING

HANDLE

SPRING & KEEPER PULLEY

VERTICAL PULL STARTER HORIZONTAL ENGAGEMENT TYPE Disassembly Procedure

DOG SPRING RETAINER BRAKE SPRING

DOG BRAKE WASHER CAM DOG CENTER SCREW

12

1. Remove the handle and relieve the starter spring tension by allowing the rope to slip past the rope clip. 2. Remove the spring cover by carefully removing the two small screws. Carefully take out the spring. 3. Remove the center hub screw and the spring hub. 4. Lift off the gear and pulley assembly. Disassemble the pulley assembly by removing the snap ring and washer (diag. 13). 5. Remove the starter rope if necessary. Replace all worn or damaged parts.

HANDLE ROPE CLIP

ROPE

SCREW

G T SP SC SP CO PU EA AN HR BR R RI VE R LL M R U A D EY ING EW NG R SN ST KE BR OU H AP WA SP AC NT U B KE ING SC SH RIN E G T R R EW

13 39

Assembly Procedure LEFT-HAND KNOT

1. Insert the rope through the starter pulley. 2. Assemble the gear, pulley, washer, and snap ring. 3. Place a small amount of grease on the center shaft, place the gear and pulley into position making sure the brake spring loop is positioned over the metal tab on the bracket. The rope clip must fit tightly onto the bracket. The raised section fits into the hole in the bracket (diag. 14 & 15).

RECEPTACLE FOR RAISED SECTION

MOUNTING BRACKET TAB MUST FIT INTO SPRING LOOP

4. Install the hub and hub screw. Torque the hub screw to 45 - 55 in. lbs. (5 - 6 Nm). A loose hub screw will prevent the rope from retracting. 5. Install the return spring if necessary. A replacement spring is installed by placing the spring and its retainer over the top of the pulley and pushing the spring out of the retainer into the pulley's recessed area.

RAISED SPOT ROPE CLIP

BRAKE

15

14

6. Install the spring cover and the cover screws. 7. Wind the rope onto the pulley by slipping it past the rope clip. When the rope is fully wound on the pulley, wind the pulley assembly two additional turns to put tension on the spring. 8. Mount the starter on the engine making sure the top of the starter gear teeth are no closer than 1/16" (1.59 mm) from the top of the flywheel ring gear teeth.

VERTICAL PULL STARTER, VERTICAL ENGAGEMENT TYPE

ROTATE COUNTERCLOCKWISE

Disassembly Procedure 1. Pull out enough rope to lock the rope in the "V" of the bracket. 2. Remove the handle if necessary by prying out the small staple in the handle with a screwdriver. 3. Place the starter bracket on the top of a deep well socket that is large enough to receive the head of the center pin. Use an arbor press to drive out the center pin. 4. Rotate the spring capsule strut until it is aligned with the legs of the brake spring. Insert a nail or pin no longer than 3/4" (19.05 mm) through the hole in the strut so it catches in the gear teeth. This will keep the capsule in the wound position (diag. 16). 5. Slip the sheave out of the bracket. CAUTION: DO NOT ATTEMPT TO REMOVE THE SPRING CAPSULE FROM THE SHEAVE ASSEMBLY UNLESS THE SPRING IS FULLY UNWOUND. 6. Squeeze and hold tightly by hand the spring capsule at the outer edge against the gear sheave.

40

STRUT

PIN

16

7. Remove the retainer pin from the strut and slowly relieve the spring tension by allowing the spring capsule to rotate slowly under control, until completely unwound. The spring capsule can now be removed from the gear sheave.

ORIGINAL INSTALLATION WITH STAPLE INSTALL NEW ROPE BY TYING LEFT-HAND KNOT

LEFT-HAND KNOT

Assembly Procedure 1. Feed the new rope through the hole and tie a lefthanded knot on the rope end. Make sure the rope and knot do not protrude from the knot cavity and bind the pulley rotation (diag. 17).

REINSTALL LEFT-HANDED KNOT

2. Wind the rope on the sheave assembly clockwise, viewing the gear from the gear side of the sheave.

PRY STAPLE OUT TO REMOVE OLD ROPE

17

3. Reinstall the brake spring, being careful not to spread the spring more than necessary. 4. Install the spring capsule, making sure the starter spring end hooks on the gear hub (diag. 18). 5. Wind the spring four full turns and align the brake spring legs with the strut as shown. Insert the pin in the strut (diag. 19).

GEAR HUB STARTER SPRING END

6. If the starter is equipped with a locking or delay pawl and spring, make sure these are in place before grasping the gear and spring capsule assembly and sliding it into the bracket. Make sure the legs of the brake spring are positioned in the slots of the bracket. 7. Feed the rope end under the rope guide and hook it into the "V" notch. Remove the pin and the strut will rotate clockwise against the bracket (diag. 21).

SPRING HOOKED ON GEAR HUB

8. Insert the new center pin by pressing or driving the pin firmly in place. Reinstall the starter assembly on the engine (diag. 21).

ROTATE SPRING 4 FULL TURNS

18

19

STARTER HANDLE ROPE

BRAKE

PULLEY

SPRING ASSY.

PAWL SPRING * CLIP * KEY*

STRUT PAWL

ROPE CLIP

GUIDE BRAKE ENDS THROUGH SLOT

LOCKING PAWL*

BRACKET

WHEN PIN IS REMOVED STRUT WILL ROTATE 45o CLOCKWISE

21

PIN

"V"ROPE WEDGE * USED ON SOME MODELS

20

41

CHAPTER 6 ELECTRICAL SYSTEMS GENERAL INFORMATION The electrical system consists of three main elements: a battery, a starting circuit, and a charging circuit. The battery is part of both the starting and charging circuit. The battery should be checked before going into any extensive starter or charging system checks. If a battery has a shorted cell, overcharging can result, and the regulator or rectifier may appear to be at fault. If a cell has an open or high resistance connection, the electric starter operation will be affected. The power source used to provide the energy to turn an electric starter motor on Tecumseh engines is either 120 volt A.C. current or 12 volt D.C. An A.C. starter circuit utilizes a 120 volt power source instead of a battery. The 12 volt battery models require a charging system to maintain proper battery charge. The starting circuit includes the battery, battery cables, starter or ignition switch, safety switches, and an electric starter motor. The charging system consists of alternator charge coils, rectifiers or diodes, regulator, ignition switch, flywheel magnets, and a battery. All engines that have a charging system will use a combination of some or all of these features.

OPERATION STARTING CIRCUIT AND ELECTRIC STARTERS

LOCK NUT BOLT BRUSHES

After all of the safety interlock switches have been activated, the starter switch will complete the circuit. A strong magnetic force is produced by the electrical current running through the armature windings. The armature magnetism repels the magnetism produced by the permanent field magnets of the electric starter. The repelling magnetic forces cause the armature to rotate, moving the drive pinion laterally on the splined armature shaft, meshing the starter pinion gear with the flywheel ring gear. When the drive pinion contacts the stop at the end of the armature shaft, the pinion rotates along with the armature shaft to crank the engine. The armature and pinion remain positively engaged until the engine fires and the flywheel rotates faster than the armature. The greater momentum of the flywheel throws the starter pinion gear out of mesh and forces the starter pinion back to the disengaged position. After the switch is released, the starting circuit is opened and the armature coasts to a stop. A small anti-drift spring holds the pinion in the disengaged position (diag. 1).

END CAP WASHER NUTS

BRUSH SPRINGS BRUSH CARD HOUSING

ARMATURE SPRING RETAINER RETAINER

THRUST WASHER GEAR SPRING DUST COVER

END CAP ENGAGING NUT

1

CHARGING CIRCUIT When a conductor (alternating coils) cuts the magnetic field generated by the magnets in the flywheel, a current will be induced in the alternator coil. The permanent magnets in the flywheel have a magnetic field in which the lines of magnetic force run from the North Pole to the South Pole. As the flywheel rotates and the position of the magnets change, the direction of the magnetic field changes or alternates. The alternating coils are wound in different directions to allow current to flow as an A.C. waveform (diag. 2).

ROTATION OF FLYWHEEL

2 42

CONVERTING ALTERNATING CURRENT TO DIRECT CURRENT In order to charge a battery, it is necessary to convert alternating current (A.C.) to direct current (D.C.). This is accomplished by using a diode or rectifier (diag. 3). A single diode makes use of only one half of the A.C. signal and is known as HALF WAVE RECTIFICATION (diag. 4). This is acceptable in certain applications. In certain situations it is necessary to make use of the entire A.C. signal. To accomplish this, multiple diodes in a bridge configuration are used to produce FULL WAVE RECTIFICATION (diag. 5).

CATHODE

ANODE

DIRECTION OR FLOW OF CURRENT

Ý

BAND OR OTHER MARKING INDICATES CATHODE END

3

Current flows through a diode when the anode is more positive than the cathode. The cathode end of the diode should point toward the battery when diode is used between a charging system and a battery.

HALF WAVE RECTIFIER SINGLE DIODE The single diode allows only the positive half of the A.C. signal through. It does not allow the negative portion through. HALF WAVE RECTIFIER (SINGLE DIODE) + VOLTAGE

+ VOLTAGE

- VOLTAGE

A.C. INPUT - VOLTAGE

FULL WAVE RECTIFIER (BRIDGE RECTIFIER)

+ VOLTAGE

The full wave rectifier makes use of the entire A.C. signal, converting it to D.C.

- VOLTAGE

COMPONENTS

D.C. OUTPUT

FULL WAVE RECTIFIER (BRIDGE RECTIFIER)

A.C. INPUT

+ VOLTAGE (D.C.)

A.C. INPUT

BATTERY The batteries used in conjunction with Tecumseh engines are 12 volt lead acid or “maintenance free” style. The chemical energy produced by the dissimilar metals of the battery plates provides a electrical potential that is used to power the electric starter or unit accessories. Consult the original equipment manufacturer’s service manual for battery size, capacities, and testing procedure.

4

+ VOLTAGE

D.C. OUTPUT - VOLTAGE

5

WIRING The wires used in Tecumseh electrical systems are copper stranded with an insulated coating around the copper strands. CONDITION: All wiring must be fully insulated between connection points, securely fastened and free of foreign material (such as rust and corrosion) at the connection points. This is especially important in the use of batteries where much of the potential may be lost due to loose connections or corrosion. Remember to check the insulation on the wire. All it takes is a pin hole to "ground out" on the engine or frame. This is of special concern when moisture or water is present. This may cause the engine to run erratically or be impossible to start.

43

WIRE GAUGE: The proper thickness of wire is necessary in all electrical circuits. Wire diameter is measured in increments of gauge numbers. As the gauge number of the wire increases, the wire diameter decreases in size (diag.6).

THE LARGER THE NUMBER THE SMALLER THE WIRE

1. The starter circuit wiring must be rated at #6 or lower gauge number.

# 18

#6

2. The charging circuit wiring must be rated at #16 or lower gauge number (20 amp system requires #14 or lower gauge number).

6

3. The magneto circuit wiring (ground circuit) must be rated at #18 or lower gauge number. Tecumseh's standard engine wiring color codes, effective August, 1992 are as follows: Code

Product

Yellow

-

Alternator A.C. Leads

Red

-

Alternator D.C. + Leads

Brown

-

Alternator D.C. - Leads

Black

-

Alternator Ground Leads, Battery Ground Leads

Orange

-

12 Volt Starter B + Leads

Dark Green -

Ignition Shut-Off Leads

NOTE: PRIOR TO AUGUST 1992, WIRE CODES CHANGED ACCORDING TO MODEL AND SPECIFICATION NUMBERS.

ELECTRICAL TERMS ALTERNATOR - An alternator consists of coils of wire wound around a metal lamination stack. When a magnet is moved past the coils, a current is induced in the coils. In general, the greater the number of coils, the greater the output of the alternator (diag. 7).

7

IGNITION COIL - The ignition coil is used to fire the spark plug. It is completely independent from the alternator coils. RECTIFIERS and DIODES - Charging a battery requires that the alternating current produced by the alternator be changed to direct current. This is accomplished by using a diode or rectifier. REGULATOR/RECTIFIERS - This combines a regulator with a rectifier. The regulator prevents overcharging of the battery and the rectifier changes the alternating current to direct current (diag.8, 9, 10). CONDUCTORS - A conductor is a material that allows an electric current to pass through it. All metals are conductors of electricity, but some are better conductors than others. Silver, copper and gold are some of the better known conductors. As the temperature of the conductor increases, the resistance increases.

8

9

INSULATORS - An insulator is a material that will not allow an electric current to pass through it. Some of the more common materials that are insulators are glass, plastic, rubber, ceramics and porcelain.

10 44

BASIC CHECKS Before going into extensive checks, be sure to perform the more basic checks first, such as: 1. Battery defective or not charged. 2. Corroded or loose terminals and connections, or wrong connections. 3. Cracked insulation or broken wires. 4. A wire "grounding out" in the system. 5. Defective switch. 6. Operator presence system functioning properly.* *NOTE: ALL LAWN AND GARDEN TRACTORS BUILT AFTER JULY OF 1987 ARE REQUIRED TO HAVE AN OPERATOR PRESENCE SYSTEM AND MANY CAME EQUIPPED WITH SUCH A SYSTEM PRIOR TO THIS DATE. IF THE TRACTOR IS "CUTTING OUT" OR WILL NOT START, THIS IS AN AREA THAT SHOULD BE CHECKED OUT.

45

TROUBLESHOOTING ELECTRICAL STARTER CIRCUIT FLOW CHART

Starter will not turn

NO

YES

Is there power at the power source?

Repair or replace power source

Starter turns at low rpms or stalls under load

Intermittent starter operation

NO

Is power supplied to the starter terminal?

Check wiring, connections, safety switches, starter switch

Check starter for binding brushes, worn brushes, dirty or oily commutator

NO

NO

Remove spark plug, does engine turn over freely?

YES

Isolate engine from the equipment, does engine turn over?

YES

YES

Repair or replace equipment causing excessive loading YES

Internal engine failure or flywheel interference

NO

Reinstall spark plug, does engine bind on compression stroke?

YES

Check valve lash. Adjust if necessary. Does the engine turn over without binding now?

NO Repair or replace electric starter

46

Internal engine failure, repair or replace engine

TROUBLESHOOTING ELECTRICAL CHARGING CIRCUIT FLOW CHART

Identify the charging system used by model and specification number or visually check the electrical plug

Consult the Quick Reference Service Guide for test procedures on the different charging systems available.

Test for either AC or DC voltage as directed at the proper engine RPM

NO

NO

Is the voltage greater than or equal to the minimum value?

Is AC voltage before diode or YES rectifier greater than the minimum value?

Alternator coil failure, replace coil assy.

YES

Check wiring, switches, or ammeter for breaks, shorts

Check diodes, replace if no continuity exists or if continuity exists reversing test leads

Check fuses, replace as necessary

Check switches, wiring, or lights for shorts

47

TESTING PROCEDURE STARTING CIRCUIT 1. Check the power source using an electrical tester and follow the testers recommended procedure. Make sure the battery meets the minimum battery voltage requirements found in the original equipment manufacturer's service manual. 2. Check the electric starter terminal for the required voltage (12v D.C. or 120 v A.C.) using a voltmeter. CAUTION: FOLLOW ALL SAFETY PRECAUTIONS WHEN TESTING FOR A.C. VOLTAGE, ELECTRIC SHOCK CAN KILL. 3. Check wiring, connections, fuses, ignition or starter switch, safety switches, or solenoid for continuity using a ohmmeter or a continuity light. Repair or replace as necessary. 4. Remove all equipment loads from the engine. Take off all drive belts, chains, and couplers to isolate the engine from the equipment it is powering. 5. Try to turn the engine over using the recoil assembly if equipped. If the engine doesn’t turn over, a mechanical binding may be the cause. Check for proper lubrication (oil level and viscosity), starter gear and flywheel ring gear interference. If no problem is discovered, the problem is an internal failure. 6. If the engine binds only on the compression stroke, check the engine valve clearance per the specification table in Chapter 10. If the valve clearance is within the specifications, the camshaft (compression release) may require replacement. Valve clearance not within the listed specifications will require either resetting or grinding the valve stems to obtain the proper clearance. 7. If the engine turns over freely, the electric starter should be disassembled and checked. If the preceding steps fail to correct the problem, the engine will require disassembly to find the mechanical failure. See Chapter 9 under "Disassembly Procedure".

CHARGING CIRCUIT The following pages will show wiring diagrams of several Tecumseh charging systems. The charging system used on the engine is best identified by obtaining the engine model number and the specification number on the engine. Consult a Tecumseh dealer or a parts manual to identify the charging system. To make many of the tests it is necessary to run the engine and measure alternator output with a voltmeter. When making voltage tests with the engine running, it is not necessary to take readings at all the listed R.P.M.s. Checking at one of the speeds is sufficient. In some cases an open circuit D.C. check cannot be made. An SCR (Silicon Controlled Rectifier) is located in the circuit which requires a minimum “turn on” voltage to allow it to conduct. Without the battery in the circuit this “turn on” voltage is not present. The SCR “senses” this and there will be no D.C. output from the regulator or rectifier. Each charging system has its own testing procedure. Test the charging system using the applicable procedure on the following pages. (+) POSITIVE LEAD

350 Milliamp Charging System Models: Rotary Mower Engines Equipped with Electric Start CHECKING THE SYSTEM: The battery must be in the circuit to perform the test properly. Connect a voltmeter across the battery. The voltmeter should read the battery voltage. Start the engine. With the engine running, there should be an increase in the voltage reading. If there is no change in the voltage reading, the alternator is defective and should be replaced. See Chapter 9 for "Disassembly Procedure" (diag. 11). NOTE: SET THE VOLTMETER TO THE 0-20 VOLT D.C. SCALE FOR THE TEST.

(-) ENGINE GROUND MAGNETO GROUND (GR) BATTERY GROUND (BL) BLACK

48

D.C. OUTPUT LEAD (RED) ELEC. STARTER LEAD (ORG) RED

11

18 Watt A.C. Lighting Alternator Models: H35, HS & HSSK 40-50, HM & HMSK 70-80-100 CHECKING THE SYSTEM: To check the system, disconnect the plug from the rest of the lighting system. Connect a wire lead from the single pin connector coming out of the engine to one terminal of a No. 4414, 18 watt bulb. Connect another wire lead to the other terminal of the bulb and run to a good ground on the engine. Start the engine and test the circuit using the A.C. voltmeter as shown (diag. 12).

ENGINE

YELLOW

With the engine running, minimum A.C. voltage across the bulb should be: 2000 R.P.M. - 6.0 Volts A.C. 3000 R.P.M. - 8.5 Volts A.C.

#4414 BULB

3600 R.P.M. - 10.0 Volts A.C.

12

If minimum values are noted, the alternator is okay. If less than the minimum values, the alternator is defective. See Chapter 9 for "Disassembly Procedure".

1 Amp (18 Watt) Add-on Alternator YELLOW

CHECKING THE SYSTEM: To check the system, disconnect the plug from the rest of the lighting system. Connect a No. 4414, 18 watt bulb in line with each terminal in the plug. Start the engine and test the circuit using a voltmeter as shown (diag. 13).

YELLOW

With the engine running, minimum A.C. voltage values across the bulb should be: 2000 R.P.M. - 8.0 Volts A.C. 3000 R.P.M. - 10.5 Volts A.C. #4414 BULB

3600 R.P.M. - 12.0 Volts A.C. If minimum values are noted, the alternator is okay. If the minimum values are not noted, the alternator or A.C. connector is defective. See Chapter 9 for "Disassembly Procedure".

13

BLACK

D.C. Charging Adaptor

OUTPUT LEADS

Rectifier Bridge Check With Ohmmeter for D.C. Adaptor RED

The following tests should be performed without the engine running to determine the condition of the D.C. adaptor.

BLACK RED

Continuity should exist during one of the two following tests. No continuity should exist while performing the opposite test. If continuity exists during both tests, or if no continuity exists during both tests, the D.C. adaptor is defective.

A.C. TERMINALS

TEST NO. 1 - Connect negative probe of meter to red output lead. Connect positive probe of meter to both A.C. terminals and black output lead (diag. 14).

#4414 BULB

14 (continued on top of next page)

49

TEST NO. 2 - Connect the positive probe of meter to red output lead. Connect the negative probe of meter to both A.C. terminals and black output lead. Connect the negative probe of meter to black output lead. Connect the positive probe of meter to both A.C. terminals and red output lead. If the D.C. adaptor is not defective and a known good battery fails to hold a charge, then perform an A.C. output voltage test. NOTE: PRIOR TO AUGUST 1992, THE BLACK WIRE WAS BROWN. CHECKING THE SYSTEM: To check the system, disconnect the D.C. adaptor from the add-on alternator. Connect a No. 4414, 18 watt bulb in line with each terminal in the alternator. Start engine and test circuit using an A.C. voltmeter as shown (diag 14). With the engine running, minimum A.C. voltage values across the bulb should be: 2000 R.P.M. - 8.0 Volts A.C. 3000 R.P.M. - 10.5 Volts A.C. 3600 R.P.M. - 12.0 Volts A.C. If the minimum values are noted, alternator is okay. If the minimum values are not noted, the alternator or A.C. connector is defective.

2.5 Amp D.C., 35 Watt Lighting To check this system follow the meter hook ups at the right, checking the D.C. negative and D.C. positive first. If output is below standard listed, pull back protective coating in front of the diode and check A.C. output. If A.C. is good check each diode it services as requested see parts list. (diag. 15)

TWO DIODES

D.C.

TO POSITIVE SIDE OF BATTERY

RED D.C. NEGATIVE OUTPUT LEAD (BROWN D.C.)

D.C. value (+) or (-) check. A.C. outputs both sides. R.P.M. D.C. Volts 2500 - 8.0 Volts D.C. 3000 - 9.5 Volts D.C. 3300 - 10.5 Volts D.C. 3600 - 11.5 Volts D.C.

R.P.M. 2500 3000 3600 -

Volts A.C. 18 Volts A.C. 22 Volts A.C. 26 Volts A.C.

NOTE: These minimum numbers should be obtained by your meter and will often be higher.

D.C. POSITIVE OUTPUT LEAD (RED D.C.)

D.C.

A.C.

15

3 Amp A.C. Lighting Alternator Models: H & HSK 30- 35, HS & HSSK 40, H & HSK 50-60, HH50-60, HM & HMSK 70-80-100, HHM80 Before making any exterior tests, check for an inoperative switch, shorted wires and burned out headlight and/or stop tail light. To check out the alternator, check the A.C. lead to ground (diag. 16).

HEAD & TAIL LIGHT

YELLOW

With engine running, minimum values should read: 2500 R.P.M. - 8.0 Volts A.C. 3000 R.P.M. - 9.5 Volts A.C. 3300 R.P.M. - 10.5 Volts A.C. 3600 R.P.M. - 11.5 Volts A.C. If the above minimum readings are noted, the alternator is okay. Check for defective lights, wiring or switches. If less than the above readings, the alternator is defective. See Chapter 9 for "Disassembly Procedure". 50

GREEN YELLOW IGNITION GROUND STOP LIGHT

16

NOTE: ON OLDER POINT IGNITION SYSTEMS, THE A.C. OUTPUT LEADS ARE BLACK AND RED.

3 Amp D.C. Alternator System - Rectifier Panel This 3 amp system is readily identified by the rectifier panel in the circuit. The panel includes two diodes and a fuse for overload protection. The rectifier panel does not regulate the output of this system. CHECKING THE SYSTEM: Check the fuse to determine if it is good. A continuity light or ohmmeter can detect a faulty fuse. Replace with a six (6) amp fuse if necessary. Determine if the diodes are functioning properly. A continuity light may be used to check diodes. (diag. 17). When replacing the diode in the rectifier panel, locate the undercut on one end of the diode and match it to the detent on terminal clip of the rectifier panel.

+

17 GREEN

D.C. VOLTMETER YELLOW

YELLOW

FUSE +

PROBE

Test the D.C. output of the rectifier panel as follows: Disconnect the battery lead from the terminal of rectifier panel. Use D.C. voltage meter probe on + battery terminal as shown in the diagram (diag. 18). Connect negative lead to engine ground. Minimum values should read:

-

TO ENGINE GROUND

18 RECTIFIER PANEL A.C. MOUNTED ON VOLTMETER ENGINE

2500 R.P.M. - 12.0 Volts D.C. 3000 R.P.M. - 14.0 Volts D.C. 3300 R.P.M. - 16.0 Volts D.C. 3600 R.P.M. - 18.0 Volts D.C. If these minimum readings are noted, the system is okay. Check for bad battery, ammeter, wiring, etc.

FUSE

19

If less than above reading, proceed to make an A.C. output check. With the battery lead disconnected from rectifier panel, probe the A.C. terminals with the voltmeter on the A.C. scale (diag. 19). Minimum values should read: 2500 R.P.M. - 24.0 Volts A.C. 3000 R.P.M. - 29.0 Volts A.C. 3300 R.P.M. - 32.0 Volts A.C. 3600 R.P.M. - 35.0 Volts A.C. If less than above output, generating coil assembly is defective. See Chapter 9 for "Disassembly Procedure". NOTE: There is no regulator in this system. The total output of the two diodes is three (3) AMPS. If the battery is overcharging (boiling and bubbling), reduce the D.C. input by one-half by removing one of the diodes.

51

3 Amp DC Alternator System - Diode in Harness Sleeve Models: H30-35, HS40, H50-60, HH50-60, HM70-80-100, HHM80

GREEN

This system has a diode included in the red wire which converts the alternating current (A.C.) to direct current. The direct current (D.C.) is used to provide a trickle charge for the battery. The leads from the alternator and the type of connector may vary, but the output readings will be the same.

RED GROUND PROBE (+)

CHECKING THE SYSTEM: Remove the fuse from the fuse holder and check the fuse to make certain it is good. If faulty, replace with a six (6) AMP fuse.

20

To check D.C. output, separate the connectors at the engine. Place the probe (+) in the red wire lead connector. Ground the other probe to the engine (diag. 20). With the engine running minimum values should read: DIODE

2500 R.P.M. - 8.0 Volts D.C. 3000 R.P.M. - 9.5 Volts D.C.

PROBE (+) GREEN

3300 R.P.M. -10.5 Volts D.C. 3600 R.P.M. -11.5 Volts D.C. If these minimum readings are noted, the system is okay. Check for bad battery, ammeter, wiring, etc.

GROUND

RED

21

If less than the above readings, proceed to make an A.C. output check by pulling back the protective coating from the fuse holder and diode. Using an A.C. voltmeter, check voltage from a point between the engine and the diode as shown in the diagram (diag. 21). With the engine running, minimum values should read: 2500 R.P.M. - 18.0 Volts A.C. 3000 R.P.M. - 22.0 Volts A.C. 3300 R.P.M. - 24.0 Volts A.C.

If low or no voltage is experienced, replace the alternator. If the alternator puts out the minimum A.C. voltage, replace the diode. To replace the diode, disconnect at plug (spade terminal) and cut the wire on the opposite end of the diode at the solderless (crimped) connector. Remove 1/4" (6.35 mm) of insulation from the cut end of the wire and twist the strands together. Place the solderless connector from the new diode onto the exposed 1/4" (6.35 mm) wire and crimp the connector with a standard electricians pliers. Reconnect plug end (or spade connector (diag. 22).

52

SPADE CONNECTOR

SOLDERLESS CONNECTOR

Þ

3600 R.P.M. - 26.0 Volts A.C.

FUSE HOLDER

22

5 Amp Alternator System Regulator-Rectifier Under Blower Housing

INSERT PROBES INTO CONNECTOR SLOTS. DO NOT REMOVE CONNECTOR WIRES.

CHECKING THE SYSTEM: An open circuit D.C. voltage check cannot be made with this system. If a known good battery fails to maintain a charge, proceed to make an A.C. voltage test. To do this, the blower housing must be removed, and the regulator-rectifier must be brought outside of the blower housing.

A.C. VOLTMETER

Disconnect the red D.C. output connector at the wiring harness and connect the probes from an A.C. voltmeter to the wire terminals at the regulator-rectifier (diag. 23). CAUTION: AT NO TIME SHOULD THE ENGINE BE STARTED WITH THE BLOWER HOUSING REMOVED.

CAUTION: BLOWER HOUSING MUST BE INSTALLED WHEN RUNNING ENGINE

23

With the engine running, the minimum values should read: 2500 R.P.M. - 19.0 Volts A.C. 3000 R.P.M. - 23.0 Volts A.C. 3300 R.P.M. - 26.0 Volts A.C. 3600 R.P.M. - 28.0 Volts A.C. If the minimum values are noted, the alternator is okay; the regulator-rectifier is defective. If less than above readings, the alternator is defective. See Chapter 9 for "Disassembly Procedure".

3 Amp D.C. 5 Amp A.C. Alternator Models: H & HSK 50-60, HH50-60, HM & HMSK 70-80-90-100, TVM125-140-170-195-220, TVXL195-220 This unit combines a 3 Amp D.C. system used to charge a battery with a 5 Amp A.C. system used for lighting. Located in the red wire of the harness is a diode which converts the alternating current to direct current for charging the battery. The yellow wire provides the A.C. voltage for the lighting circuit.

RED DIODE YELLOW D.C.

24

(continued on top of next page) 53

CHECKING THE SYSTEM: To check the system, disconnect the plug and measure the D.C. voltage at the red wire terminal (diag. 24). Measure the A.C. voltage at the yellow wire terminal. With the engine running, the minimum values should be: 3 Amp D.C. 2500 R.P.M. - 8.0 Volts D.C. 3000 R.P.M. - 11.0 Volts D.C. 3600 R.P.M. - 13.0 Volts D.C. RED

5 Amp A.C. 2500 R.P.M. - 8.0 Volts A.C. 3000 R.P.M. - 11.0 Volts A.C. 3600 R.P.M. - 13.0 Volts A.C.

A.C.

YELLOW

25

If the above minimum values are noted, system is okay. Check for defective lights, wiring or switches. If less than above values are noted, pull back the protective shrink tubing from the diode. Using an A.C. voltmeter, check the voltage going into the diode from alternator, at the lead on the alternator side of the diode (diag.25).

D.C. VOLTMETER

All Models B + TERMINAL WIRE

With the engine running, the minimum values should read: 2500 R.P.M. - 20.0 Volts A.C. 3000 R.P.M. - 25.0 Volts A.C. 3300 R.P.M. - 26.5 Volts A.C. 3600 R.P.M. - 29.0 Volts A.C. If low or no voltage is experienced, replace the alternator. If the alternator puts out the minimum A.C. voltage, replace the diode.

REGULATOR/RECTIFIER MUST BE GROUNDED

7 Amp Alternator System Regulator-Rectifier External to Engine

26

CHECKING THE SYSTEM: To check the system, disconnect the D.C. or B+ wire at the switch end and measure D.C. voltage between the lead and ground (diag. 26). With the engine running, minimum values should read: 2500 R.P.M. - 9.0 Volts D.C. 3000 R.P.M. - 11.0 Volts D.C. 3600 R.P.M. - 14.0 Volts D.C.

A.C.

If the minimum readings are noted, system is okay. Check for defective ammeter, wiring, etc. If less than the above readings, disconnect the plug from the regulator-rectifier, and insert the A.C. voltmeter probes in the two outside terminals (diag. 27). With the engine running, minimum values should read: 2500 R.P.M. - 12.0 Volts A.C. 3000 R.P.M. - 14.0 Volts A.C. 3600 R.P.M. - 18.0 Volts A.C. If the minimum readings are noted, the alternator is okay; the regulator-rectifier is defective. If less than the above readings, the alternator is defective. See Chapter 9 for "Disassembly Procedure". 54

27

7 Amp Alternator System RegulatorRectifier Under Engine Block Housing Models: H50-60, HH50-60, HM70-80-100, HHM80, TVM125-140-170-195-220

FULL WAVE

In this system, the regulator and rectifier are combined in one solid state unit mounted under the blower housing of the engine.

HALF WAVE

HALF WAVE

MAGNETO GROUND - GREEN

Various types of regulator-rectifiers have been used on different applications. Test procedures for all types are the same. However, regulator styles are not interchangeable (diag. 28). CHECKING THE SYSTEM: An open circuit D.C. voltage check cannot be made with this system. If a known good battery fails to maintain a charge, proceed to make an A.C. voltage test.

D.C. OUTPUT LEAD-RED

To do this, the blower housing must be removed, and the regulator-rectifier must be brought outside of the blower housing. Keep the A.C. leads attached to the regulator-rectifier. Install the blower housing with the regulator-rectifier outside the housing. With an A.C. voltmeter probe the regulator as shown (diag. 29)

INSERT PROBES INTO CONNECTOR SLOTS DO NOT REMOVE CONNECTOR WIRES

CAUTION: AT NO TIME SHOULD THE ENGINE BE STARTED WITH THE BLOWER HOUSING REMOVED.

YELLOW

RED

With engine running, minimum A.C. voltage from lead to lead should be: CAUTION: BLOWER HOUSING MUST BE INSTALLED WHEN RUNNING ENGINE

2500 R.P.M. - 16.0 Volts A.C. 3000 R.P.M. - 19.0 Volts A.C. 3300 R.P.M. - 21.0 Volts A.C. 3600 R.P.M. - 23.0 Volts A.C.

28

A.C. VOLTMETER

29

If the minimum readings are noted, the alternator is okay. If the system fails to charge a known good battery, the regulator-rectifier must be defective.

B+ TERMINAL WIRE

10 Amp Alternator System - RegulatorRectifier-External to Engine In this system, the regulator and rectifier are combined in one solid state unit.

GREEN

CHECKING THE SYSTEM: To check the system, disconnect the D.C. or B+ wire at the switch end and measure D.C. voltage between the lead and ground (diag. 30).

REGULATOR/ RECTIFIER MUST BE GROUNDED

YELLOW

30

With the engine running, minimum values should read: 2500 R.P.M. - 13.0 Volts D.C. 3000 R.P.M. - 16.0 Volts D.C. 3600 R.P.M. - 20.0 Volts D.C. If the minimum values are noted, the system is okay. Check for defective ammeter, wiring, etc. If less than the above readings, disconnect the plug from the regulator-rectifier, and insert the A.C. voltmeter probes in the two outside terminals (diag. 31). (continued on top of next page)

31 55

With the engine running, minimum values should read: 2500 R.P.M. - 16.0 Volts A.C. 3000 R.P.M. - 19.0 Volts A.C. A.C. OUTPUT YELLOW

3600 R.P.M. - 24.0 Volts A.C. If the minimum readings are noted, the alternator is okay; the regulator-rectifier is defective. If less than above readings, the alternator is defective. See Chapter 9 for "Disassembly Procedure".

A.C.

32

10 Amp Alternator Models: H & HSK 50-60, HH50-60, HM & HMSK 70-80-100, HHM80, TVM125-140-170-195-220 CHECKING THE SYSTEM: Unplug the connector at the wiring harness supplied by the OEM. Proceed to make an A.C. output check. Place one lead of the A.C. voltmeter on the center plug of the connector. Place the other lead to engine ground (diag. 32). With the engine running, minimum values should read: 2500 R.P.M. - 16.0 Volts A.C. 3000 R.P.M. - 20.0 Volts A.C.

If less than above output, the alternator assembly is defective. See Chapter 9 for "Disassembly Procedure".

3300 R.P.M. - 22.0 Volts A.C.

12 Amp D.C. Regulated Alternator Models: HM80-100, OHM90-110, OHV110-130, TVM220 CHECKING THE SYSTEM: Unplug the connector at the wiring harness supplied by the OEM. Proceed to make an A.C. output check. Place one lead of the A.C. voltmeter on the center plug of the connector. Place the other lead to engine ground. With the engine running, minimum values should read: 2500 R.P.M. - 16.0 Volts A.C. 3000 R.P.M. - 20.0 Volts A.C.

If less than above output, the alternator assembly is defective. See Chapter 9 for "Disassembly Procedure".

3600 R.P.M. - 25.0 Volts A.C.

VOLTAGE REGULATORS If a known good or load tested battery fails to maintain a charge, the charging system and the regulator can be checked using a voltmeter. Set the voltmeter on the 0-20 Volt D.C. scale and connect the probes across the battery terminals as shown. Note the battery voltage. Start the engine, the voltage reading should increase from the noted battery voltage but not exceed 15 Volts D.C. If no voltage increase is noted, proceed to make an A.C. voltage check using the applicable procedure. If the battery voltage exceeds 15 Volts D.C., or the proper minimum A.C. voltage is noted during the check, replace the regulator.

LOW OIL SHUTDOWN SWITCHES Low Oil Shutdown (Brown Wire)

Check the LOS switch while it is in the engine. The engine must be level, and the oil level at the full mark. Place the speed control in the run position. Remove the spark plug wire from the spark plug. Install a gap type tester connected to the spark plug wire and a good engine ground. Spin the engine over using the electric or recoil starter. A bright blue spark should be seen at the tester. If not, remove the blower housing and disconnect the LOS lead from the ignition module. Reinstall the blower housing and spin the engine over. If spark occurs now, replace the LOS switch. If no spark is seen, replace the ignition module. 56

Ground (Black Wire)

Ignition Coil (Green Wire)

33

ON/OFF LIGHTED ROCKER SWITCH WITH LOW OIL SHUTDOWN (LOS)

SERVICE This section covers the service procedures for the 12 and 120 volt electric starters. For diagnosis of the starting circuit see “Electrical Starter Troubleshooting” in this chapter. Illustrations may not be identical in configuration to the starter being serviced, but procedures and tests apply unless otherwise stated.

12 VOLT OR 120 VOLT ELECTRIC STARTERS WITH EXPOSED SHAFT 1. Remove the plastic dust cover on the armature end (diag. 34). 2. Push down the spring retainer and remove the retainer ring. 3. Slide off the spring retainer, anti-drift spring, gear, and drive nut. 4. If internal service is necessary, scribe a line across the cap assemblies and armature housing to aid in reassembly. 5. Remove the two or four retaining nuts from the through bolts holding the cap assembly. 6. Slide off the cap assembly. The terminal insulator slides out of the commutator cap.

34

7. Remove the armature. 8. Inspect and replace as necessary. 9. Use the reverse procedure for reassembly.

GEAR

SPRING

RETAINER RING

ARMATURE

10. Inspect flywheel ring gear for damage before installation.

12 VOLT D.C. OR 120 VOLT A.C. ELECTRIC STARTERS WITH CAP ASSEMBLY

DRIVE NUT

1. Remove the retainer ring from the armature shaft (diag.35).

SPRING RETAINER

CAP ASSY.

35

2. Remove the two nuts from the through bolts holding the cap assembly on. 3. Slide off the cap assembly. The engaging nut, gear, spring, and spring retainer will remain in the cap assembly. 4. If complete disassembly is required, refer to step # 4 in the previous section for additional steps. 5. Inspect and replace as necessary. Use reverse procedure for assembly. ( For ease of assembly, place the armature into the brush end frame first.) 6. Inspect flywheel ring gear for damage before installation.

(continued on top of next page)

57

INSPECTION AND REPAIR 1. The pinion gear parts should be checked for damage or wear. If the gear does not engage or slips, it should be washed in solvent ( rubber parts cleaned in soap and water) to remove dirt and grease, and dried before reassembly. Also check the armature and drive nut splines for wear or damage. Replace parts as necessary. 2. The brushes and brush card holder should be checked for wear. With the armature in place and the brushes engaging the commutator surface, check the brushes for wear. Brushes should be replaced if the brush wire approaches the bottom of the brush holder slot. Brush springs must exhibit enough strength to keep tension on the brushes and hold them on the commutator. 3. The field windings can be checked using a continuity light or ohmmeter. Attach one lead to each field coil connection. Continuity should exist between each field coil connection, and no continuity should exist between the field coil connections and the starter housing (diag. 36 & 37).

FIELD COIL CONNECTORS

FIELD COIL CONNECTORS

BRUSH SPRINGS 12 VOLT

4. The armature should be checked for glazing or wear. If necessary the armature can be turned down in a lathe. While rotating, polish the commutator bars using a piece of 00 sandpaper (diag. 38). Light pressure and back and forth movement should be used. Recut the commutator bars to a depth equal to the width of the insulators between the bars. Check for continuity between the copper commutator bars and the iron of the armature, none should exist (diag. 39). If any is noted the armature must be replaced.

CONNECTION POINT OF POWER CORD LEADS

36

38

120 VOLT

37

39

Brush Card Replacement 1. Loosen but do not remove the two nuts on the starter terminal post. 2. Remove the nuts holding the end cap in place. Remove the end cap and the thrust washer. 3. Grasp the thru bolts using a vise grip positioned as close to the flanged end as possible to prevent thread damage. Remove the two nuts holding the driving end cap in place. Remove the armature and driving cap assembly, followed by the two thru bolts. Notice the position of the brush ground eyelet under the thru bolt flange. 4. Note or mark the position of the connectors of the brush wires. Use a wire cutter to clip the solid field wires as close to the connectors as possible. 5. Note or mark the brush card in the starter housing and remove the brush card assembly. Clean the accumulated dirt off all starter parts. Scrape the insulating varnish off the last 1/2" (12.7 mm) of the solid field wires. 6. Insert the new brush card into position while guiding the solid field wires through the proper slots in the brush card. 7. Crimp and solder the brush leads to the solid field wires. Use a needle nose pliers or vise grip to hold the woven brush lead close to the connector while soldering. This prevents solder and heat from flowing up the brush lead. Insulate the crimped connection nearest the starter terminal post using electrical tape or heat shrink tubing. Route the wires to prevent damage during assembly. 8. Install the armature into the housing while spreading the brushes. Install the thru bolts while checking to make sure the bolts go thru the ground brush eyelet terminals. Install and tighten the drive end thru bolt nuts, but do not overtighten. 9. Install the thrust washer (cupped side faces towards the end cap) on the end of the armature and then install the starter end cap. Secure the cap with the locking nuts and tighten the nut on the starter terminal post. Rotate the armature by hand to check for binding before installation on the engine.

58

CHAPTER 7 FLYWHEEL BRAKE SYSTEMS GENERAL INFORMATION Tecumseh’s brake systems provide two methods of meeting compliance standards which has become a federal law as of June 30, 1982. There are two additional methods used by equipment manufacturers that also meet compliance standards and they are as follows: 1. Use of the blade brake clutch in conjunction with either a top or side mounted recoil starter or 12 volt electric starter. The blade stops within three seconds after the operator lets go of the blade control bail at the operator position and the engine continues to run. Starter rope handle is either on the engine or on the equipment handle. 2. Use of a recoil starter (top or side mounted) with the rope handle on the engine as opposed to within 24 inches (60.9 cm) of the operator position. This method is acceptable if the mower deck passes the 360 degree foot probe test. A specified foot probe must not contact the blade when applied completely around the entire blade housing. This alternative can be used with engine mounted brake systems and typical bail controls. The blade stops within three seconds after the operator lets go of the engine/blade control bail at the operator position. Tecumseh’s Flywheel Brake system provides consumer safety by stopping the engine and blade within three seconds after the operator releases the engine/blade control bail at the handle of the lawnmower. These systems are available on both recoil and electric start models. The engine stopping time is affected by the engine R.P.M. Consult microfiche card #30, the Plus 1 or Parts Smart Look-Up system, or Service Bulletin #107 to determine the correct engine RPM or blade tip speed.

OPERATION BOTTOM SURFACE SYSTEM In the stop position with the handle mounted engine / blade control released, the torsion spring rotates the brake lever forcing the brake pad against the underside of the flywheel, actuates the ignition kill switch and on electric start models, opens the starter interlock switch (diag. 1). In order to restart the engine, the handle mounted engine / blade control must be applied. This action pulls the brake pad away from the flywheel, opens the ignition kill switch and on electric start models, closes the starter interlock switch. This will allow the engine to be started by energizing the starter with a starter switch (diag. 2).

BRAKE APPLIED

BRAKE RELEASED

IGNITION SHORTED

INTER-LOCK SWITCH OPEN

IGNITION OPEN

INTER-LOCK SWITCH CLOSED

1

2 59

OPERATION (CONTINUED) INSIDE EDGE SYSTEM In the stop position the brake pad is applied to the inside edge of the flywheel, at the same time the ignition system is grounded (diag. 3). In order to restart the engine, the brake control must be applied. This action pulls the brake pad away from the inside edge of the flywheel and opens the ignition kill switch. On electric start systems the starter is energized by an ignition switch or a two motion control. On non-electric start systems, the recoil starter rope must be pulled to start engine (diag. 4).

IGNITION SHORTED

BRAKE APPLIED

IGNITION OPEN

BRAKE RELEASED

3

4

COMPONENTS Both the Bottom Surface and the Inside Edge systems use the following components: The brake lever and pad assembly consists of a steel lever with a brake pad bonded to the lever (diag. 5). The ignition kill switch is a plastic block with a wire extending out of it. The wire is attached to a terminal which is connected to the ignition kill wire. The brake lever contacts and grounds the wire of the switch when the engine / blade control is released, and the ignition module is grounded. This in turn kills the ignition (diag. 5).

The interlock switch is a push button switch that is activated by the brake lever when the engine / blade control is actuated. If there is a starter switch used to start the engine, the interlock switch acts as a safety switch and will not allow the starter to crank unless the engine / blade control is depressed. Where a two motion control is used the interlock switch is utilized as the starter switch. The Torsion Spring supplies the pressure to the brake lever and brake pad to stop the flywheel. The Control Cable transfers the motion of the engine / blade control to the brake system.

60

BRAKE LEVER AND PAD

IGNITION KILL SWITCH

TORSION SPRING

CONTROL CABLE

INTERLOCK SWITCH

5

SERVICE If the brake system fails to kill the ignition and stop the blade within 3 seconds the following service procedures should be followed.

FLYWHEEL REMOVAL NOTE: BEFORE THE FLYWHEEL IS REMOVED OR REPLACED, THE BRAKE PRESSURE ON THE FLYWHEEL MUST BE RELIEVED AS OUTLINED BELOW UNDER "BRAKE LEVER AND PAD". Remove the flywheel as outlined in Chapter 9 under "Disassembly".

BRAKE LEVER AND PAD

UNHOOK TORSION SPRING

Bottom Surface To relieve the brake pressure on the flywheel, remove the torsion spring by firmly grasping the short end of the spring with a pliers and unhook the spring from the bracket then remove the flywheel (diag. 6). Remove the brake lever and pad assembly. Inspect the brake pad for dirt, oil or grease contamination. If the pad is contaminated, or if there is less than .060" (1.524 mm) of brake pad material at the pad's thinnest point, replacement is necessary. The brake pad is bonded to the brake lever and must be replaced as an assembly. Install the brake lever and pad assembly and continue to reassemble the brake system in the reverse order of disassembly.

6

SHORT END OF SPRING

NOTE: WHEN REMOVING THE BRAKE BRACKET THE TORSION SPRING MUST BE RELEASED BEFORE THE TOP STARTER BOLT IS REMOVED OR THE THREADS IN THE CYLINDER BLOCK WILL BE DAMAGED.

ALIGN HOLES SWITCH

Inside Edge

LEVER

To relieve the brake pressure on the flywheel, compress the spring by moving the lever toward the spark plug, when the hole in the lever aligns with the hole in the bracket, secure the lever with alignment tool 670298 then remove the flywheel (diag. 7). Remove the alignment tool. Release the spring tension by unhooking the short end of the spring from bracket with a pliers. Remove the “E” clip from the brake pad shaft. Slide the pad lever from the shaft and unhook the link. Inspect the brake pad for dirt, oil or grease contamination. If the pad is contaminated, or if there is less than .060" (1.524 mm) of brake pad material at the pad's thinnest point, replacement is necessary. The brake pad is bonded to the brake lever and must be replaced as an assembly. Rehook the link, install the brake lever and pad assembly, install the "E" clip, rehook the short end of the spring and continue to reassemble the brake system in the reverse order of disassembly.

670298

7

GROUNDING CLIP

8

GROUNDING CLIP POSITION LINKAGE

IGNITION GROUNDOUT TERMINAL Inspect the ignition kill switch grounding clip for proper alignment and contact with the brake arm. Insure that all electrical connections are clean and secure (diag. 8 & 9).

"E" CLIP

BRAKE PAD

9 61

STARTER INTERLOCK SWITCH The engine / blade control must close the interlock switch before the starter can be engaged. To check the interlock switch, use an ohmmeter or continuity light to perform a continuity check. Continuity should exist between the two terminals when the interlock switch button is completely depressed. No continuity should exist when the button is released. If the switch fails replace the switch (diag. 10).

10

To replace the interlock switch, carefully grind the heads off of the rivets that fasten the interlock switch to the brake bracket. Remove the rivets from the back side of brake bracket. Use the self-tapping screw supplied with the new switch to make threads in the bracket. Install the interlock switch onto the brake bracket in the proper position and secure the switch to the brake bracket with the machine screws supplied. Be careful not to overtighten the screws as switch breakage can occur (diag. 11).

SELF TAPPING SCREW MACHINE SCREWS

11

CONTROL CABLE Bottom Surface The control cable conduit must be assembled against the stop in the bracket. Make sure the bottom of the lever completely depresses the button on the starter interlock switch, if equipped, when the control is fully applied. The cable must provide enough travel so the brake will contact the flywheel. Some slack should exist in the cable adjustment to compensate for brake pad wear (diag. 12).

Inside Edge If replacing the cable conduit screw with a screw other than a service part replacement, be certain that the screw length is not too long as to prevent free travel of the lever. Make sure the button on the starter interlock switch is completely depressed when the control is fully applied. The cable must provide enough travel so the brake will contact the flywheel. Some slack should exist in the cable adjustment to compensate for brake pad wear (diag. 13).

BRAKE BRACKET REPLACEMENT The tension must be relieved on the lower brake spring prior to the removal of the top electric starter bolt, or damage to the threads in the cylinder block can occur. When installing a inside edge brake bracket assembly, be sure the slotted holes in the brake bracket are all the way down on the fasteners. This will properly align the brake bracket to the flywheel brake surface (diag. 14).

62

STOP

SCREW END MUST NOT BLOCK LEVER ACTION

12

CABLE CLAMP SCREW

13

MOUNTING HOLES

Ô Ô MECHANISM FULL DOWN BEFORE SCREWS TORQUED

14

CHAPTER 8 IGNITION GENERAL INFORMATION The ignition systems used on Tecumseh engines are either solid state capacitor discharge modules or magneto ignition systems. The basic functional difference is that the solid state modules are triggered by an electronic switch (SCR). Magneto ignition systems rely on the mechanical action of opening and closing a set of moveable contact points to trigger when the spark will occur. The solid state ignition system consists of a flywheel magnet and key, charge coil, capacitor, a silicon controlled rectifier, pulse transformer, trigger coil, high tension lead, and a spark plug. Everything except the flywheel magnet, key and the spark plug are located in a encapsulated ignition module. This solid state (CDI - Capacitive Discharge Ignition) module is protected by epoxy filler from exposure to dirt and moisture. This system requires no maintenance other than checks of the high tension lead and spark plug. The Tecumseh magneto ignition consists of a stator assembly made of laminations, a coil, contact points, condenser, a permanent magnet mounted in the flywheel, high tension lead, and a spark plug. The coil is sealed by epoxy filler, and the points and condenser are sealed from dirt and moisture by a crankshaft seal and cover gasket.

OPERATION SOLID STATE IGNITION SYSTEM (CDI) As the magnets in the flywheel rotate past the charge coil, electrical energy is produced in the module. The energy is stored in the capacitor ( approx. 200 volts) until it is released by an electrical switch (SCR). As the magnet continues to rotate, it travels past a trigger coil where a low voltage signal is produced. This low voltage signal closes the SCR switch, allowing the energy stored in the capacitor to flow to a transformer where the voltage is increased from 200 volts at 200 RPM to 22,000 volts at 3000 RPM. This voltage flows through the high tension lead to the spark plug where it arcs across the electrodes and ignites the air-fuel mixture (diag. 1). 1

MAGNETO IGNITION SYSTEM (POINTS) As the flywheel turns, the magnets that are mounted in the wheel, pass the coil mounted on the stator. As the magnet's North Pole enters the area of the center leg of the stator, a magnetic field is concentrated through the laminations to the magnet's South Pole. This causes a generation of current flow in the coil's primary winding. The ignition points are closed (diag. 2). As the flywheel continues to rotate, the North Pole approaches the last leg of the lamination stack. The magnetic field through the center leg reverses, producing a large change in the magnetic field, and a high current in the primary side of the coil (diag. 3).

PATH OF MAGNETIC LINES OF FORCE

MAGNET

FLYWHEEL ROTATION

POINTS CLOSED

2

At this time, the contacts open and the primary current stops flowing. This change in current causes a voltage in the primary, which induces a high voltage in the secondary winding of the coil. The voltage travels through the spark plug wire, to the spark plug and jumps the gap of the plug to ignite the air/fuel mixture. POINTS OPEN

3 63

IDENTIFICATION OF TECUMSEH IGNITION SYSTEMS INTERNAL IGNITION

EXTERNAL IGNITION

4

5

SOLID STATE IGNITION (CDI)

6

COMPONENTS OF A TECUMSEH MAGNETO IGNITION SYSTEM (DIAG. 7) A. Flywheel with magnets B. Coil

C. CONDENSER A. FLYWHEEL WITH MAGNETS B. COIL

C. Condenser

G. STATOR PLATE

D. Spark plug E. Contact points F. Ignition cam

E. CONTACT POINTS D. SPARK PLUG

G. Stator plate (dust cover, cam wiper, and laminations.)

H. FLYWHEEL KEY F. IGNITION CAM 7

H. Flywheel key The flywheel with magnets provide the magnetic flux (or field) which is necessary to induce the low voltage in the primary circuit. A horseshoe magnet is a good example of how the magnets function in the flywheel. The magnets are either cast in or glued onto the flywheel, and are not a replaceable item (diag. 8). The ignition coil is used to increase the low voltage in the primary to high voltage in the secondary, capable of jumping the spark plug gap. The coil consists of a primary and a secondary winding of wire. The primary is the low voltage (200 - 300 volts) winding, consisting of approximately 150 turns of heavy gauge wire next to the core. The secondary winding consists of approximately 10,000 turns of very fine wire wrapped over the primary. When induced by the primary, the secondary winding generates a voltage of between 10,000 - 20,000 volts, which can arc the spark plug gap (diag. 9). 64

8 PRIMARY WINDING GROUND LEAD

SECONDARY WIRING

PRIMARY LEAD HIGH TENSION LEAD

9

The condenser acts as an electrical shock absorber to prevent arcing between the contact points as they open. Arcing will lower the voltage at the spark plug, as well as burn and pit the contact points. The condenser is a replaceable item (diag. 10). 10 The spark plug is made up of two electrodes. The outside electrode is grounded and secured to the threaded sleeve. The center electrode is insulated with porcelain. The two are separated by an air gap which creates a resistance. A large voltage from the secondary arcs the air gap which causes a spark and ignites the air-fuel mixture in the cylinder (diag. 11).

The contact points consist of an insulated, movable point that connects to the coil primary lead, and a stationary point that is grounded to the stator body. Spring tension holds the points together making a complete path for the primary circuit, and are opened by the action of the point arm which rests on the ignition cam. The contact points are a replaceable item (diag. 12).

11

12

The ignition cam is an oblong device which rotates with the crankshaft, and opens the points for firing the ignition system. It is important to check the ignition cam for roughness, if rough replace the cam. When inserting the ignition cam onto the crankshaft make sure that the side stamped "TOP", or the side that has an arrow on it faces the mechanic (diag. 13). 13 NOTE: SOME IGNITION CAMS ARE MACHINED DIRECTLY ONTO THE CRANKSHAFT AND ARE NOT REPLACEABLE.

The stator plate is an aluminum fixture which houses the points, cam wiper, condenser, and has the laminations riveted to it. The laminations are strips of iron riveted together to form an iron core. Rust or debris in between the laminations will hamper the performance of the ignition system. If corrosion on the laminations is severe, the stator plate should be replaced (diag. 14). 14

The flywheel key locates the flywheel to the crankshaft in the proper position. If a flywheel key is sheared, or partially sheared, the engine will not start or be difficult to start (diag. 15).

15 65

IGNITION TROUBLESHOOTING Engine runs erratically or shuts off, restarts

Engine Will Not Start

Check for spark Spark

No Spark Replace spark plug

Check flywheel for damaged or sheared key Isolate engine and repeat test Set proper air gap on external coil

Set proper point gap, check condensor and timing

Test coil for intermittent or weak spark

Check electric starter and battery if applicable

Spark

No Spark

Equipment problem, check switches, wiring and equipment controls

Engine problem, check for shorts or grounds in wiring

Parasitic load

Disconnect ignition cut-off wire at the ignition coil & repeat test

Oil shutdown or on/off rocker switch

Check for proper air gap on external coil and repeat test

Check flywheel magnets for strength

Test ignition module

66

TESTING PROCEDURE 1. Check for spark using a commercially available spark tester and following the tester's recommended procedure. 3/4 " (19.05 mm)

2. Check for the correct spark plug and for cracks in the porcelain, pitted or burned electrodes, excessive carbon buildup, and proper air gap setting. Replace if questionable. 3. Remove the blower housing, disconnect the ignition ground lead at the ignition coil (solid state only). Reinstall the blower housing and crank the engine over. If spark occurs, check the ignition switch, safety interlock switches, electrical wiring for shorting to ground, or oil shutdown switch.

MAGNETS

16

NOTE: STANDARD POINT IGNITION MAY HAVE TO BE DISCONNECTED AT THE IGNITION SHUTOFF (AT THE SPEED CONTROL). 4. Check the air gap between the flywheel magnets and the laminations of an externally mounted coil or module. It should be .0125 (.317 mm) or use gauge part # 670297. 5. Check the flywheel magnets for the proper strength using this rough test. Hold a screwdriver at the extreme end of the handle with the blade down, move the blade to within 3/4 inch (19.05 mm) of the magnets. If the screwdriver blade is attracted to the magnets, the magnetic strength is satisfactory (diag. 16). 6. Examine the stator components (diag. 17).

17

A. Check the ignition cam for roughness. B. Check the movable point arm that rests on the ignition cam for wear. C. Check the spring steel on the point assembly for evidence of excessive heat. D. Check contact points for wear. If they are pitted or burned, this is an indication that the condenser is not functioning properly. If any of the above are faulty, replace accordingly. E. When replacing the points, also replace the condenser. F. After the points are replaced and engine is re-timed, be sure to clean the points with lint free paper. An engine will not run smoothly if the points are improperly set or coated with even a small quantity of oil, etc.

18

7. Examine the coil and lamination assembly (either internal or external) for cracks in the insulation or other damage which would cause shorts or leakage of current. Make sure the electrical leads are intact, especially where they enter the coil (diag. 18). 8. Check the operation of the coil using an approved tester. Follow the instructions furnished with the test unit or booklets offered by the Tecumseh Products Co. Engine and Transmission Group Service Division. If the coil or lamination assembly is defective, replace as necessary. NOTE: IF LAMINATIONS ARE BAD ON AN INTERNAL COIL ASSEMBLY, THE ENTIRE STATOR BODY MUST BE REPLACED SINCE THE LAMINATIONS ARE PERMANENTLY RIVETED TO THE STATOR. External coils are permanently attached to the lamination and must be serviced as an assembly. 67

SERVICE To remove ignition components from the engine, see Chapter 9 under "Disassembly".

SPARK PLUG SERVICE Spark plugs should be removed, cleaned, and adjusted periodically. Check the air gap with a spark plug gap gauge and adjust accordingly. Set the spark plug gap at .030" (.762 mm) (diag. 19). 19

Replace the plug if the center and ground electrodes are pitted or burned, or if the porcelain is cracked or discolored. When reinstalling the plug make sure it is clean of all foreign material.

NOTE: DO NOT USE A SAND BLASTER TO CLEAN PLUGS, MICROSCOPIC PARTICLES LEFT IN THE PLUG CAN SCORE THE ENGINE CYLINDER DURING OPERATION. USE A SOLVENT AND A WIRE BRUSH TO CLEAN, AND BLOW OUT THOROUGHLY WITH COMPRESSED AIR. Replace the spark plug with the proper spark plug. Consult the proper parts breakdown for the spark plug to be used in the engine being serviced. Set the spark plug gap at .030" (.762 mm). Install the spark plug and tighten to 250 inch pounds torque (28.5 Nm). If a torque wrench is not available, screw spark plug in as far as possible, by hand, and use a spark plug wrench to turn spark plug 1/8 to 1/4 of a turn further if using the old spark plug or 1/2 of a turn further if using a new spark plug.

CONDITIONS CAUSING FREQUENT SPARK PLUG FOULING 1. Carburetor setting too rich or air cleaner restricted. 2. Partially closed choke shutter. 3. Poor grade of gasoline. 4. Improper fuel. 5. Restricted exhaust system.

NORMAL

CARBON DEPOSIT

WORN

OIL DEPOSIT

6. Incorrect spark plug. 7. Incorrect spark plug gap. 8. Oil level too high, or breather is restricted. 9. Faulty piston rings. 10. Weak ignition system.

20

IGNITION TIMING PROCEDURE In order for an engine to run effectively and efficiently, the spark must ignite the compressed air-fuel mixture when the piston is in a specific position to deliver maximum power. This position is known as Before Top Dead Center (BTDC). If the mixture is ignited too soon, kickback can be experienced due to preignition. If the mixture is ignited too late, loss of power can be experienced due to retarded spark.

The Standard Point System Internal coils are used on small and medium frame 4 cycle engines. First check the specification charts in the back of this manual or the quick reference chart for the correct ignition dimensions, (point gap setting and timing specification) depending on the model of engine. 68

Begin the procedure by replacing the points if necessary. To do this remove the nut that secure the movable portion of the breaker points. Remove the screw from the stationary portion of the breaker points and the worn breaker point assembly. Install a new breaker point assembly and adjust the point gap. This is done by rotating the crankshaft until the point arm is resting on the high side of the ignition cam. Set the point gap by loosening the screw on the movable point set and insert a feeler gauge per specification. Adjust the point gap so that a light drag is felt on the feeler gauge. Tighten the screw and recheck the gap. Leave the leads unattached for the timing procedure. Use this procedure on all standard point ignition systems when point replacement is necessary (diag. 21). Install a dial indicator (Part # 670241), equipped with the correct tip on the extender leg. Use the small tip for engines with timing dimensions of between top dead center (T.D.C.) and .050" (1.27 mm) before top dead center (B.T.D.C.). Use the large tip for engines with timing dimensions of between .051" (1.295 mm) B.T.D.C. to .150" (3.81 mm) B.T.D.C. Make sure to secure the extender leg in position to locate the tip directly over the piston head. Loosen the screw on the side of the adaptor sleeve to allow the sleeve to be turned into the threads of the spark plug hole, not the entire dial indicator. This will ensure the proper location of the tip. Once the adapter sleeve is secured in the hole, tighten screw on sleeve adaptor to prevent the dial from moving up or down, which would give a false reading (diag. 22).

ARM

PIVOT

POINTS

21 DIAL SCREW

SLEEVE

SLEEVE SCREW

22

Find T.D.C. with both valves closed by rotating the crankshaft clockwise when looking at the magneto end of the crank, until the needle on the dial stops and reverses direction. Where the needle stops is T.D.C. Loosen the screw on the dial, and rotate the dial so that zero is lined up with the needle at T.D.C. Tighten the screw on the dial to secure it in place (diag. 23). While watching the needle on the dial indicator, rotate the crankshaft counterclockwise when looking at the magneto end of the crank, .010" (.254 mm) past the B.T.D.C. dimension. Then rotate the crankshaft clockwise to the proper B.T.D.C. dimension, this will take out any slack between the connecting rod and crankshaft assembly.

IGNITION CAM

CRANKSHAFT

DIAL AT 0"

23 DIAL AT .080" (2.032 mm)

DIAL AT .090" (2.286 mm)

Example: If the specification of .080" (2.032 mm) is the B.T.D.C. dimension, rotate the crankshaft counterclockwise so that the needle on the dial indicator travels to .090" (2.286 mm) B.T.D.C. (diag. 24), then rotate the crankshaft clockwise so that the needle travels to the specified dimension of .080" (2.032 mm) B.T.D.C. (diag. 25).

24

25

Next, if the original breaker points are being used, disconnect the leads from the point terminal. Reinstall the nut & tighten. Connect one lead of a continuity light, or ohmmeter to the point terminal and the other lead to a good ground. Loosen the two bolts holding down the stator and rotate the stator until the continuity light or ohmmeter indicates a break in the circuit. Torque down the stator bolts while maintaining the stator plate position and the timing procedure is completed. Reconnect the leads on the point terminal and tighten the nut making sure that the leads do not touch the flywheel (diag. 26). 26 (continued on top of next page)

69

Before putting the dust cover back on the points box, clean the points by sliding lint free paper back and forth between the contacts. Manually, open the points when removing the paper to eliminate paper fibers from remaining between the contact points (diag. 27).

LINT FREE PAPER

Fixed Timed System (External coil) This system has the contact points and condenser mounted under the flywheel with the laminations and coil mounted outside the flywheel. This system is identified by the square hole in the stator, the round configuration of the coil, and on older coils, the word "Grey Key" is stamped on the coil to identify the proper flywheel key to be used. When ordering an external coil for replacement from Tecumseh Products, a solid state module will be received as a replacement. The new module will be supplied with the proper flywheel key (diag. 28).

27

Torque down the stator bolts to secure the stator in place. Next, rotate the crankshaft until the point arm is resting on the high side of the ignition cam. Set the point gap at .020" (.508 mm), by loosening the screw on the movable point, and insert a .020" (.508 mm) feeler gauge between the contact points (diag. 29). Tighten the screw on the movable point and then recheck the point gap. Be sure to clean contact points with lint free paper (diag. 27).

28

NOTE: The flywheel key used on engines with an external coil and points looks similar to the solid state key, however, timing will be effected if the wrong key is used.

Reinstall the proper flywheel key, flywheel, washer and torque down the flywheel nut to specification. Reinstall the external coil and set the proper air gap to .0125" (.3175 mm) using air gap gauge, part # 670297 between the magnets and laminations and torque the mounting screws to specification. Remove the air gap gauge and rotate the flywheel to check for any possible striking points. If none are found, the air gap is set correctly and the timing procedure is completed (diag. 30).

Solid State Ignition Timing Timing is set using a .0125" (.3175 mm) air gap gauge (Part No. 670297). Loosen the two hold-down screws, insert the .0125" (.3175 mm) remove semi-color gauge between the laminations and the magnet on the flywheel. Slide the solid state ignition assembly against the air gap gauge and the flywheel magnet. Torque the two hold down screws to the correct specification and remove the air gap gauge. Rotate the flywheel one full revolution to check for any possible striking points. If none are found, the air gap is set correctly and the timing procedure is completed (diag. 30).

70

29

.0125 (.3175 mm)

30

Other Solid State Systems The following systems are located under the flywheel. All components are encapsulated into one module. No timing is necessary with this type (diag. 31, 32, 33). Check the system by checking for a spark or use a commercially available test equipment.

SERVICE TIPS DO NOT:

31

Interchange flywheels, flywheel keys, spark plugs, condensers, or points. (Some systems do not use standard points and condensers.) Use flywheels with cooling fins that are broken off. Reglue ceramic magnets back onto the inside of the flywheel. Re-oil the cam wiper in a magneto system. Use a standard business card as an air gap gauge. File the contact points. Attempt to reglue the spark plug lead back into a coil or a solid state module. Store a solid state module within 20 feet (6.1 meters) of an unshielded welder.

32

PLEASE DO: Follow directions carefully. Lookup the correct ignition dimensions in the proper mechanic's manual or quick reference chart, for the engine being repaired. Clean points with lint free paper after setting gap. Reinstall the point terminal nut and tighten after removing leads, before timing procedure. Remember to correctly TIME a Tecumseh engine, even when just changing points on a magneto system. Remember to use correct air gap gauge. Check for correct flywheel key which effects timing.

33

71

CHAPTER 9 INTERNAL ENGINE AND CYLINDER GENERAL INFORMATION This chapter covers the cylinder block, piston and rod assemblies, cylinder head, crankshaft, camshaft, valve train, breather, cylinder cover, flywheel, counterbalance systems, and lubrication systems. The governors and the governor systems are covered in Chapter 4. All Tecumseh engines covered in this manual are four cycle engines with the valves in the engine block. The crankshaft position is designated as either horizontal or vertical as the engine rests on its base. The engines identified by decals or model as XL (Extra Life) or XL/C (Extra Life / Commercial ) are made using aluminum alloy diecast around a cast iron cylinder liner. However, not all engines with cast iron cylinder liners are identified as XL or XL/C. Engine blocks of the heavy frame series (HH, VH) are made of cast iron. All other engines use aluminum alloy for the cylinder block along with pistons that are chromium plated.

OPERATION 4-CYCLE ENGINE THEORY All 4-cycle engines require four piston strokes to complete one power cycle. The flywheel on one end of the crankshaft provides the inertia to keep the engine running smoothly between power strokes. The camshaft gear is twice as large as the mating gear on the crankshaft so as to allow proper engine valve timing for each cycle. The crankshaft makes two revolutions for every camshaft revolution. 1. INTAKE. The intake valve is open and the exhaust valve is closed. The piston is traveling downward creating a low pressure area, drawing the air-fuel mixture from the carburetor into the cylinder area above the piston (diag. 1).

INTAKE

COMPRESSION 1

2

2. COMPRESSION. As the piston reaches Bottom Dead Center (BDC) the intake valve closes. The piston then rises, compressing the air-fuel mixture trapped in the combustion chamber (diag. 2). 3. POWER. During this piston stroke both valves remain closed. As the piston reaches the Before Top Dead Center (BTDC) ignition point, the spark plug fires, igniting the air-fuel mixture. In the time it takes to ignite all the available fuel, the piston has moved to Top Dead Center (TDC) ready to take the full combustive force of the fuel for maximum power during downward piston travel. The expanding gases force the piston down (diag. 3). 4. EXHAUST. The exhaust valve opens. As the piston starts to the top of the cylinder, the exhaust gases are forced out (diag. 4). After the piston reaches Top Dead Center (TDC), the four stroke process will begin again as the piston moves downward and the intake valve opens.

72

POWER

3

EXHAUST

4

LUBRICATION SYSTEMS The lubrication system used with all Tecumseh horizontal crankshaft engines covered in this manual utilize a splash type system. An oil dipper on the connecting rod splashes oil in the crankcase to lubricate all internal moving parts. Some engines have the dipper as an integral part of the connecting rod assembly, while others have a dipper that is bolted on with one of the rod bolts (diag. 5). All vertical shaft engines use a positive displacement plunger oil pump or rotary type oil pump. Oil is pumped from the bottom of the crankcase, up through the camshaft and over to the top main bearing. Oil under pressure lubricates the top crankshaft main bearing and camshaft upper bearing (diag. 6). On all Tecumseh vertical shaft 4-cycle engines, the oil is sprayed out under pressure through a small hole between the top camshaft and crankshaft bearing to lubricate the piston, connecting rod, and other internal parts (diag. 7). The plunger style oil pump is located on an eccentric on the camshaft. As the camshaft rotates, the eccentric moves the barrel back and forth on the plunger forcing oil through the hole in the center of the camshaft. The ball on the end of the plunger is anchored in a recess in the cylinder cover (diag. 8).

DIPPER

5 SPRAY MIST HOLE CRANKSHAFT PASSAGE PLUG

MAIN BEARING OIL GROOVE CRANKSHAFT OIL PASSAGE CURRENT (TVM195, 220)

CAMSHAFT DRILLED CAMSHAFT PASSAGE

BARREL TYPE LUBRICATION PUMP

6

ASSEMBLE PUMP BARREL WITH INSIDE CHAMFER TOWARD CAMSHAFT GEAR

SPRAY MIST HOLE OIL DRAIN HOLE

7

8

COUNTERBALANCE SYSTEMS Some Tecumseh engines may be equipped with an UltraBalance® counterbalance system. This system uses a single weighted shaft that is driven off the crankshaft. The shaft's function is to counteract the imbalance caused by the counterweights on the crankshaft and the combustion forces (diag. 9).

DRIVE GEAR

COUNTERBALANCE SHAFT

GOVERNOR FLANGE CAMSHAFT

9 73

COMPONENTS The cylinder block houses the piston, valves and along with the cylinder cover all the internal components. The block is a one piece diecast aluminum alloy or cast iron cylinder casting (diag. 10). The piston transmits the force of the burning and expanding gases through the connecting rod to the crankshaft. The piston rings provide the seal between the cylinder wall and the piston. The rings keep the combustion pressures from entering the crankcase and also wipe the oil off the cylinder wall and return it to the sump. The connecting rod assembly is the link between the piston (piston pin) and the crankshaft. The cylinder head is a one piece aluminum alloy or cast iron casting that is bolted to the top of the cylinder block. The many fins provide cooling for the engine. The crankshaft converts the up and down piston movement to the rotational force (torque) by an offset crankpin or rod journal. The camshaft lobes raise and lower the lifters at the proper time to allow air and fuel in and exhaust out of the cylinder. Teeth on the camshaft gear time the camshaft to the crankshaft. The valves allow air-fuel mixture to enter the cylinder and exhaust gases to exit. The valves provide a positive seal when closed. The valve springs return the valves to the closed position and must be strong enough to maintain valve lifter and cam lobe contact. The valve retainers lock the spring to the valve stem. The valve lifters maintain contact on the camshaft and push the valves open. The crankcase breather is a one way check valve that allows air out and prevents air from coming in. It allows the engine to develop a partial vacuum in the crankcase during operation. The cylinder cover (or flange on verticals) provides the bearing surface for the power take off (P.T.O.) end of the crankshaft and camshaft. This bolted on cover is removed to provide access to all internal components. The oil pump (vertical shaft only) consists of a steel plunger and a nylon housing that rides on the camshaft eccentric. The flywheel provides the mass to smooth the effects of one power stroke every other crankshaft revolution. Flywheels are made of aluminum alloy or cast iron. The flywheel fins act as a fan to cool the engine. CYLINDER COVER

CYLINDER HEAD CYLINDER BLOCK

PISTON RINGS

VALVES

PISTON CONNECTING ROD

VALVE SPRINGS CRANKCASE BREATHER

VALVE LIFTERS CRANKSHAFT

74

CAMSHAFT

FLYWHEEL

10

ENGINE OPERATION PROBLEMS

ENGINE KNOCKS

OVERHEATS

Associated equipment loose or improperly adjusted

Excessive engine loading

Check for excessive carbon in combustion chamber

Low oil level or wrong viscosity oil

Dirty carburetor or air filter

Loose flywheel, examine key, keyway, and proper flywheel nut torque

Cooling air flow, obstructed or clogged cooling fins

Carburetor improperly adjusted

Carburetor improperly adjusted or improper RPM setting

Governor sticking, binding or improper RPM setting

Incorrect spark plug or Ignition timing

Carburetor linkage, shafts or shutters sticking or binding

Carbon in the combustion chamber

Incorrect spark plug or Intermittent spark, check ignition

Incorrect spark plug or Ignition timing

Loose or worn connecting rod

Worn cylinder

SURGES OR RUNS UNEVENLY

Fuel cap vent obstructed

Incorrect or damaged flywheel key

EXCESSIVE OIL CONSUMPTION

Oil level above full

Lean carb setting causing overheating (adjustable carb)

Piston rings worn

Wrong viscosity oil

Worn or glazed cylinder

Excessive engine speed

Valve guides worn excessively

Engine cooling fins dirty causing overheating

Valve guides worn excessively

Breather damaged, dirty or improperly installed

Damaged gaskets, seals or "O" rings 75

ENGINE OPERATION PROBLEMS

ENGINE MISFIRES

ENGINE VIBRATES EXCESSIVELY

BREATHER PASSING OIL

Wrong or fouled spark plug

Bent crankshaft

Oil level too high

Carburetor improperly adjusted

Attached equipment out of balance

Excessive RPM or improper governor setting

Valves sticking or not seating properly

Loose mounting bolts

Damaged gaskets, seals or "O" rings

Incorrect spark plug or Ignition timing

If applicable counter balance not properly aligned

Breather damaged, dirty or improperly installed

Excessive carbon build up

Piston rings not properly seated or ring end gaps are aligned

Improper Valve Lash or Weak valve springs

Angle of operation too severe

LACKS POWER

Air intake obstructed

Lack of lubrication or improper lubrication

Carburetor improperly adjusted

Exhaust Obstructed

Improper valve lash

Loss of compression (worn rings, blown head gasket)

76

TESTING ENGINE KNOCKS 1. Check the blade hub, blade adapter, or crankshaft coupler for loose fit, loose bolts, or crankshaft key damage. Remove, inspect, replace if necessary. Reinstall and re-torque the bolts to the proper torque. 2. Check the flywheel key and the flywheel and crankshaft keyway for wear or partial shearing. Replace if any damage is evident. Tighten the flywheel nut to the proper torque. 3. Check for the correct ignition module air gap or the correct timing (point ignition). Replace the points and condenser if the points show any wear, oil, or pitting. 4. Remove the cylinder head and check for excessive carbon in the combustion chamber. Also check for the correct head gasket used, and check the spark plug for proper reach and heat range (correct spark plug for the engine). 5. Check for the proper valve lash using a feeler gauge, and check the internal components (piston, cylinder, connecting rod, crankshaft journal) for excessive clearance.

ENGINE OVERHEATS 1. Make sure the engine is not being overloaded. Remove excess load (sharpen blades, limit operation speed, process less material). 2. Check the oil level and viscosity. Add or replace as necessary. 3. Check for clogged cooling fins or obstructions to the air flow. Remove the blower housing, clean and reinstall. 4. Check the carburetor for correct adjustment or remove and clean the carburetor using tag wire and compressed air. See Chapter 3 under "Service." 5. Check the engine R.P.M. setting using a vibratach or other tachometer and compare it to the R.P.M. settings found on microfiche card #30 according to the engine model and specification number. Adjust as necessary. 6. Make sure the correct spark plug is being used. Check the ignition timing. See Chapter 8 "Ignition - Service." Correct flywheel key or partially sheared key. 7. Remove the cylinder head to check for excessive carbon buildup. Clean as necessary.

SURGES OR RUNS UNEVENLY 1. Check the fuel cap to make sure it is venting. Loosen the cap and retry engine operation. 2. Replace or clean the air filter. 3. Check the carburetor adjustment or clean the carburetor. See Chapter 3 under "Service." 4. Check the engine R.P.M. setting using a vibratach or other tachometer and compare it to the R.P.M. settings found on microfiche card #30 according to the engine model and specification number. Adjust as necessary. 5. Visually check all linkages. Check the governor shaft, throttle shaft, or pivot points for binding. 6. Check the ignition module operation using a gap type tester inserted in the high tension lead. Check for intermittent spark, incorrect spark plug, or a fouled condition.

ENGINE MISFIRES 1. Check the spark plug for the proper application or a fouled condition. Replace if questionable. 2. Reset the carburetor following the adjustment procedure or clean the carburetor. See Chapter 3 under "Service." 3. Check the ignition timing. See Chapter 8 under "Service." 4. Check for carbon buildup in the combustion chamber. 5. Inspect the valves and valve seats for leakage. Check for scoring or discoloration on the valve stem in the valve guide area. Recut the valves and seats if questionable. See "Valve Service" in this chapter. (continued on top of next page)

77

ENGINE VIBRATES EXCESSIVELY 1. Check the engine crankshaft on the PTO end for bends using a straight edge, square or a dial indicator. Blades or adapters must be removed. Any deflection will cause a vibration problem. 2. Check the engine mounting bolts, make sure they are tight. 3. Remove and check the attached equipment for an out of balance condition. 4. If the engine is equipped with a counterbalance shaft, check the gear timing to determine if the counterbalance is out of time.

BREATHER PASSING OIL 1. Check the oil level, make sure the engine is not overfilled. Also verify that the viscosity rating on the container of the oil being used is to specification. 2. Check the angle of operation. Avoid prolonged use at a severe angle. 3. Check the engine R.P.M. setting for excessive R.P.M. using a vibratach or other tachometer and compare it to the R.P.M. settings found on microfiche card # 30 according to the engine model and specification number. Adjust the high and low R.P.M. as necessary. 4. Check for leaking or damaged gaskets, seals, or "O"-rings. External leaks may not be evident; however, the leak may prevent the engine from achieving a partial crankcase vacuum. 5. Check the breather for damage, dirty condition, or improper installation. The oil return hole(s) must face down. 6. Check the engine compression using a compression tester. If the engine has weak compression, determine the cause of weak compression: worn rings, leaking head gasket, or leaking valves. Follow the compression tester's procedure.

EXCESSIVE OIL CONSUMPTION 1. Check the oil level, oil viscosity on the container of the oil being used, and oil condition. Replace and fill to the proper level. 2. Check the angle of operation. Avoid prolonged use at a severe angle. 3. Check for leaking or damaged gaskets, seals, or "O"-rings. External leaks may not be evident, however, the leak may prevent the engine from achieving a partial crankcase vacuum. 4. Check the engine R.P.M. setting using a vibratach or other tachometer and compare it to the R.P.M. settings found on microfiche card #30 according to the engine model and specification number. Adjust as necessary. 5. Check the breather for damage, dirty condition, or improper installation. The oil return hole(s) must face down. 6. Clean the cooling fins to prevent overheating. 7. Check the carburetor setting causing a lean running condition, overheating the engine. 8. Check the engine compression using a compression tester. If the engine has weak compression, determine the cause of weak compression: worn rings, leaking head gasket, or leaking valves. Follow the compression tester's procedure. 9. Check the valve guide clearance for excessive wear.

LACKS POWER 1. Check the air intake for an obstruction (dirty filter, oil saturated filter, other debris). 2. Check the oil level, oil viscosity on the container of the oil being used and oil condition. Replace and fill to the proper level. 3. Readjust the carburetor or remove the carburetor for cleaning. See Chapter 3 under "Service." 4. Check the exhaust for a restriction preventing proper exhaust flow.

78

(continued on top of next page)

5. Check the engine valve lash. Reset the valves at the proper lash. 6. Check the valves for proper seating and valve guide lash. Recondition the valves and seats. Replace the valves if necessary. 7. Check the ignition timing. Check the flywheel key for partial shearing. PRESS IN AND LIFT HERE TO RELEASE COVER

COVER BEZEL

SERVICE DISASSEMBLY PROCEDURE The following procedures apply to most engine models. Actual procedure may vary. 1. Disconnect the high tension lead from the spark plug. Remove the spark plug. 2. Drain the oil from the crankcase. Drain or shut off the fuel supply. 3. Remove the air cleaner assembly.

MODEL AND D.O.M. NUMBER DECAL LOCATED UNDER COVER (IF SO EQUIPPED)

4. Remove the fuel tank if it is attached to the engine. Fuel tanks may be held on with bolts, screws, or some models require taps upward with a soft face hammer loosening the plastic tank wedged in the blower housing slots.

11 SOCKET WRENCH

FLYWHEEL

On some LEV engine models, removal of the bezel cover is necessary to view the engine identification or to provide access to the recoil assembly screws. Push in toward the spark plug end (as shown), lift up to clear the recoil, then pull the cover away from the spark plug to remove. (diag. 11) 5. Remove the blower housing by first unscrewing the screw holding the dipstick tube to the blower housing or unscrewing the dipstick tube and removing the remaining bolts on the blower housing. 6. Unplug the ignition kill wire from the terminal on top of the ignition module and unbolt the ignition module. 7. Remove the flywheel nut, washer, and starter cup. Use a strap wrench (part # 670305) to hold the flywheel from turning (diag. 12). Thread the appropriate flywheel knock-off tool part # 670103, (7/16") or part # 670169 (1/2") on the crankshaft until it bottoms out, then backoff one complete turn. Using a large screwdriver, lift upward under the flywheel and tap sharply and squarely on the knock-off tool to break the flywheel loose. If necessary, rotate the flywheel a half turn and repeat until it loosens (diag. 13). A flywheel puller (part # 670306) may be used on engines with cored holes and also on flywheels with holes drilled and tapped (diag. 14).

FLYWHEEL TOOL

METAL HAMMER

12

KNOCK OFF TOOL

SCREWDRIVER TO RAISE FLYWHEEL

13

NOTE: DO NOT USE A JAW TYPE PULLER. 8. Remove the flywheel key, stator, and baffle plate. 9. Remove the muffler. 10. Remove the intake pipe and the carburetor. Be careful not to bend or damage the linkage when removing. Mark the hookup points or diagram the linkage arrangement to aid in reassembly. 11. Remove the cylinder head. 12. Remove the crankcase breather. 14 (continued on top of next page)

79

13. Remove the cylinder cover or mounting flange using a seal protector positioned in the seal to prevent seal damage. The crankshaft must be free of rust or scale to slide the cover off the crankshaft. H30-HS50 horizontal crankshaft engines with ball bearings on the crankshaft require the oil seal and the snap ring to be removed prior to the cylinder cover removal. On engines equipped with 8 1/2:1 gear reduction, turn the crankshaft to roll the reduction shaft gear off the crankshaft worm gear when removing the cylinder cover (diag. 15, 16, 17, 18). 1. PTO Shaft 2. Thin Washer

6. Retainer 3. Gear

4. Tang 5. Thick Washer Washer

OIL SLEEVE TOOL MOUNTING FLANGE OIL SEAL

17

15 OIL SEAL REMOVED WORM GEAR

16 14. Remove the internal components. Align the timing marks on all engines except VM70, 80, 100, HHM80, HM70, 80, 100, TVM170, 195, 220 to relieve valve lifter pressure. On these engines it is necessary to rotate the camshaft clockwise three (3) teeth past the aligned position to allow the compression release mechanism to clear the exhaust valve lifter and to allow the camshaft to be removed (diag. 19 & 20).

SNAP RING

BEVELED TOOTH

CRANKSHAFT GEAR

18 TIMING MARK

CAMSHAFT GEAR

19

15. Remove the lifters, rod cap, and balance shaft or gears if applicable. 16. Before removing the piston, remove any carbon from the top of the cylinder bore to prevent ring breakage. Push the piston out the top of the cylinder bore. 17. Remove the valves by using a valve spring compressor to compress the valve spring and rotate the valve spring retainer to allow the valve stem to pass through. Lift the valves out of the cylinder block. Remove the spring assemblies being careful to note the differences, the original placement of the springs and the presence of seals. Reinstall the spring assemblies on the same valve in the reverse order as they are removed.

80

EXHAUST CAM ROLL PIN CAM GEAR

SPRING INTAKE CAM PLUNGER (COMPRESSION RELIEF PIN)

20

CYLINDERS Visually check the cylinder for broken or cracked fins or a scored cylinder bore. Check the main bearings for wear or scoring. If the main bearings are worn or scored they can be replaced on some models. See "Crankshaft Bearing Service" in this chapter. Use a dial bore gauge or telescoping gauge with a micrometer to accurately measure the cylinder bore. Measure in the piston travel area approximately 1/2 to 3/4 of an inch (12.7 to 19.05 mm) from the top and the bottom . Measure at 90 degrees to the piston pin, 45 degrees to the piston pin, and even with the piston pin as the piston would appear when assembled. A rigid hone is recommended to "true" any cylinder irregularities. If the cylinder bore is worn more than .005" (.127 mm) oversize, out of round or scored, it should be replaced or re-sized to .010 or .020 oversize (.254 mm or .508 mm). In some cases engines are built with oversize cylinders. If the cylinder is oversize, the oversize value will be imprinted in the top of the cylinder (diag. 23). To re-size a cylinder, use a commercially available hone of the proper size. Chuck the hone in a drill press with a spindle speed of about 600 R.P.M. Start with coarse stones and center the cylinder under the drill press spindle. Lower the hone so the lower end of the stones contacts the lowest point in the cylinder bore. Rotate the adjusting nut so that the stones touch the cylinder wall and begin honing at the bottom of the cylinder. A light honing oil should be used to lubricate and cool while honing. Move the hone up and down at a rate of 50 strokes per minute to avoid putting ridges in the cylinder wall. Every fourth or fifth stroke, move the hone far enough to extend the stones one inch beyond the top and bottom of the cylinder bore. Check the bore diameter every twenty or thirty strokes for size and a 35o - 45o crosshatch pattern. If the stones collect metal, clean the stones with a wire brush when the hone is removed. (diag. 21). Hone with the coarse stones until the cylinder bore is within .002 inch (.051 mm) of the desired finish size. Replace the coarse stones with finishing stones and continue honing the cylinder to the final size. Tecumseh recommends using a 390 grit hone for finishing. Clean the cylinder and crankcase with soap and water and dry thoroughly.

21 TRENCHING GAPS

Replace the piston and the piston rings with the correct oversize parts as indicated in the parts manual. Trenching has been incorporated in the cylinders of the H50, H60, HHM80, and HM100 series of engines, as well as the TVM125,140, and 220 models. Trenching improves air/fuel flow and results in increased horsepower in these engines. When reinstalling the piston, rings, and rod assembly in these engines, stagger the ring end gaps and place the ring end gaps out of the trenched area. This will prevent the rings from possibly catching the trenched area and breaking during assembly (diag. 22).

GAPS STAGGER RING END GAPS AWAY FROM TRENCHING

22

INDICATES .010 OVERSIZE CYLINDER

23

81

CYLINDER HEADS

8

Check the cylinder head for warpage by placing the head on a precision flat surface. If warped in excess of .005" (.13 mm) replace the head. Slight warpage can be corrected by placing a sheet of #400 wet /dry sandpaper on a precision flat surface and rubbing the head gasket surface in a circular pattern until the entire gasket surface shows evidence of sanding. A small amount of honing oil on the sandpaper will make it easier to slide the head. Always replace the head gasket and torque the head bolts in 50 inch pound increments in the numbered sequence to 200 inch pounds (22.5 Nm) (diag. 24 & 25). Engine models V50, H50, H60, H70, VH50, VH60, VH70 require a flat and a belleville washer on bolts numbered 1, 3, and 7. Current production HM80 and HM100 use flat washers only on bolts numbered 2 and 3 in conjunction with the gas tank mounting bolts. All other head bolts on HM80 and HM100 use a flat and a belleville washer on each bolt.

4

6

2

1

5 7 3 ALL MODELS EXCEPT HM,VM, TVM170,195,220 24 BELLEVILLE WASHER 5 (CROWN TOWARD 9 BOLT HEAD) 7 1

3 2

FLAT WASHER

8 4 TVM170,195,220,VM & HM MODEL ENGINES 6

25

INDICATES .010 OVERSIZE PISTON

Engine models V60, V70, TVM125, 140, 195, 220 require a flat washer and a belleville washer on all head bolts.

PISTONS, RINGS, AND CONNECTING RODS Piston The piston should be checked for wear by measuring at the bottom of the skirt 90 degrees from the piston pin hole with a micrometer. Check the ring side clearance using a feeler gauge with new ring. Clean all carbon from the piston top and the ring grooves before measuring. Visually inspect the piston skirt area for scoring or scratches from dirt ingestion. If scoring or deep scratches are evident, replace the piston. If the cylinder bore needs re-sizing, an oversize piston will be necessary. Oversize pistons are identified by the imprinted decimal oversize value imprinted on the top of the piston (diag. 26).

Rings After the cylinder bore diameter has been checked and is acceptable to rebuild, the ring end gap should be checked using new rings. Place a new compression ring squarely in the center of the ring travel area. Use the piston upside down to push the ring down (diag. 28) and measure the gap with a feeler gauge. The ring end gap must be within the specification to have adequate oil control (diag. 29). This procedure will assure correct piston ring end gap measurement. Ring side clearance should also be checked with a feeler gauge when using new rings with an old piston (diag. 27).

PISTON MEASUREMENTS ARE TAKEN AT BOTTOM OF SKIRT 900 FROM WRIST PIN HOLE

26

1ST COMPRESSION RING

SIDE CLEARANCE

2ND COMPRESSION RING

CYLINDER

3RD OIL CONTROL RING

27

PISTON PISTON RING

28

Replace the rings in sets and install the piston, rings, and rod assembly in the cylinder bore with the ring end gaps staggered. When installing new rings in a used cylinder, the cylinder wall should be de-glazed using a commercially available de-glazing tool or hone.

29 82

(continued on top of next page)

Use a ring expander to remove and replace the rings. Do not spread the rings too wide or breakage will result.

CHAMFER 1ST COMPRESSION RING

If the top compression ring has an inside chamfer, this chamfer must face UP. The second compression ring will have either an inside chamfer or an outside notch. The rule to follow is an inside chamfer always faces up. An outside notch (diag. 31) will face down or towards the skirt of the piston.

2ND COMPRESSION RING 3RD OIL CONTROL RING

30

The oil control ring can be installed with either side up. The expander (if equipped) end gap and the ring end gap should be staggered.

EMISSION RINGS 1ST COMPRESSION RING

Emission Rings

2ND COMPRESSION RING

Used on TVS, LEV, H35, VLV, HM80 and TVXL195 engines that comply with emission standards. These rings have a narrower width and a different profile (barrel faced). Barrel faced rings may be installed in either direction. The underside of the oil control ring utilizes a coil type expander. These rings conform better to the cylinder allowing for better oil control by wiping the cylinder wall cleaner. The coiled expander ring helps create a more uniform load on the cylinder wall which gives a more consistent distribution of oil. NOTE: The use of these rings on a standard nonemission piston will cause ring breakage due to its wider ring grooves.

Connecting Rods Some engine models have offset piston pins (not centered) to centralize the combustion force on the piston. Engine models LAV50, HM70, HM80, HHM80, HM100, TVM170,195, 220, have offset pistons. When installing the connecting rod to the piston it is imperative that the rod be installed correctly. The piston used on these models will have either an arrow stamped above the piston pin hole, a number cast on the inside of the piston skirt or an arrow stamped on the top of the piston (diag. 32 & 33). All other engine models use a centered piston pin. If the piston does not have an arrow or number cast inside, the piston can be installed in either direction on the connecting rod. On all engine models, the match marks on the connecting rod must align and face out when installing the assembly in the engine (diag. 34 & 35).

3RD OIL CONTROL RING

31 SHORT SIDE OF ROD

LONG SIDE OF ROD CASTING NUMBER

ARROW DIRECTION VM70, VM100, HM70-100, V80, H80, HHM80, AND TVM SERIES PISTON AND CONNECTING ROD ASSEMBLIES

32

ARROW POINTS TOWARD THE VALVES

WRIST PIN

MATCH MARKS TVM220 PISTON AND ROD

The arrow on the top of the piston must point toward the valves when installing it in the cylinder (diag. 33). The inside casting number (if present) must face toward the long side of the connecting rod. If there is an arrow on the side of the piston, the arrow must point toward the short side of the connecting rod. (diag. 32). On horizontal shaft engines, oil dippers are attached to the bottom connecting rod bolt. Some engines have the oil dipper cast in the rod cap. Consult the specification chart for the proper rod bolt torque when installing the cap. The rod bolts should be torqued in 50 inch pound (5.5 Nm) increments until the specified torque is achieved.

33

MATCH MARKS

MATCH MARKS (either location)

34

35

83

CRANKSHAFTS AND CAMSHAFTS

BEVEL CHAMFER TOOTH

Inspect the crankshaft visually and with a micrometer for wear, scratching, scoring, or out of round condition. Check for bends on the P.T.O. end using a straight edge, square or a dial indicator. CAUTION: NEVER TRY TO STRAIGHTEN A BENT CRANKSHAFT.

CRANKSHAFT GEAR

PUNCH MARK

CAMSHAFT GEAR TIMING MARK

SMALL HOBBING HOLE

The timing marks on the camshaft and the crankshaft gears must be aligned for proper valve timing. (diag. 36 & 37).

36

Camshafts

CRANKSHAFT

Check the camshaft bearing surfaces for wear using a micrometer. Inspect the cam lobes for scoring or excessive wear. If a damaged camshaft is replaced, the mating crankshaft and governor gear should also be replaced. If the crankshaft gear is pressed on it is not serviceable and the crankshaft must also be replaced. Clean the camshaft with solvent and blow all parts and passages dry with compressed air, making sure that the pins and counterweights are operating freely and smoothly on mechanical compression relief types.

GEAR KEYWAY

SMALL HOBBING HOLE

CAMSHAFT GEAR

37

Camshafts used in rotary mower engines utilize a composite gear (glass filled nylon) for the purpose of reducing internal gear noise. Mechanical Compression Release (MCR) camshafts have a pin located in the camshaft, that extends over the exhaust cam lobe, to lift the valve and relieve the engine compression for easier cranking. When the engine starts, centrifugal force moves the weight outward and the pin will drop back down. The engine will now run at full compression (diag. 38). COMPRESSION RELEASE MECHANISM

Some engines are equipped with Bump Compression Release (BCR) camshafts that have a small bump ground on the exhaust lobe of the camshaft to relieve compression (diag. 39). Newer camshafts are designated as Ramp Compression Release (RCR) and utilize a less aggressive ramp than what is used on the BCR camshaft.

38 EXHAUST

LEV Exhaust Mechanical Compression Release (MCR) Cam Bushing Service (Used in production October 1999)

INTAKE

39

Removal 1. Place an LEV cylinder in a soft jawed vice and using a nonmetallic mallet, tap a #6 easy-out into the bushing so the easy-out makes a solid contact with the cam bushing. 2. Turn counterclockwise until the easy-out goes into the bushing a sufficient amount so that the bushing can be removed without the easy-out releasing. Spin the bushing counterclockwise with the easy-out while pulling for removal. CAUTION: Cam bushings should never be reused. 3. Blow compressed air down the top main bearing oil galley to the top cam bearing. This will clean any plastic particles that might have entered into the passage from the cam bushing removal procedure. Rinse cylinder in a parts tank, then lubricate the cam bearing pocket with oil. 84

AIR FROM TOP MAIN BEARING OIL GALLEY

CAM BUSHING INSTALLED

Þ

40

Installation PLACE BUSHING

1. Lube the small end of the LEV/VSK camshaft and a new cam bushing liberally with oil. (Never reuse cam bushings once removed).

LEV/VSK CAMSHAFT WITH EXHAUST MCR

2. With the strength of your hand, place a new cam bushing on the corresponding end of the camshaft and press the bushing into the cam until flush with the casting.

VALVES 41

The valves should be checked for proper clearance, sealing, and wear. Valve condition is critical for proper engine performance. Valve clearance should be checked before removal from the engine block if a valve problem is suspected or when the valves or seats are recut. No.6

Valve clearance (between the valve stem and valve lifter) should be set or checked when the engine is cold. The piston should be at T.D.C. on the compression stroke (both valves closed). Use a valve grinder or "V" block to hold the valve square when grinding the valve stem to obtain the proper clearance (diag. 43). When servicing the valves, all carbon should be removed from the valve head and stem. If the valves are in a usable condition, the valve face should be ground using a valve grinder to a 45 degree angle. If after grinding the valve face the margin is less than 1/32 of an inch (.793 mm), the valve should be replaced (diag. 43).

CAM BUSHING

Install the valves into the guides making sure the correct valve is in the proper port. The valve stem must pass through the upper valve cap and spring. Hook the valve spring retainer on the groove in the valve stem and release the spring tension to lock the cap in place. Early models may have a pin through the valve stem. Compress the spring and cap and use a needle nose pliers to insert the pin in the valve stem hole. Release the spring and check that the pin is locked under the cap. Emissionized engines have a valve stem seal on the intake valve which prevents excess oil vapor from entering the combustion chamber. This vapor would produce an unsatisfactory exhaust emission and fail today's CARB and EPA emission standards. Tecumseh's position on emissionized engines is that oversized valves are not necessary. The emissionized valve with the valve stem seal should last the life of the engine. Therefore, seals for oversized valves do not exist for our small frame engines. Replacement of this seal is necessary if valves have been removed for service.

EASY-OUT

42

MARGIN FACE

1/32" (.793 mm)

450 FACE

Valves are not identical. Valves marked "EX" or "X" are installed in the exhaust valve location. Valves marked "I" are installed in the intake valve location. If the valves are unmarked, the nonmagnetic valve (head) is installed in the exhaust valve location. To reinstall the valves, position the valve caps and springs in the valve compartment. If the spring has dampening coils, the valve spring should be installed with the dampening coils away from the valve cap and retainer (diag. 44).

LEV/VSK CAMSHAFT WITH EXHAUST MCR

WRONG

MINIMUM DIMENSION

STEM

RIGHT

43 SPRING MUST BE SQUARE DAMPENING COILS LOCATED CLOSER TOGETHER

44 INTAKE VALVE STEM SEAL (EMISSIONIZED ENGINES)

45

NOTE: If the spring has dampening coils, they always go toward the stationary surface. 85

Valve Seats Valve seats are not replaceable. If they are burned, pitted, or distorted they can be reground using a grinding stone or a valve seat cutting tool. Valve seats are ground to an angle of 46 degrees. Check the specifications section for proper width. The recommended procedure to properly cut a valve seat is to use the Neway Valve Cutting System, which consists of three different cutters. LEV engines have a small combustion chamber and require the use of a special Neway cutter #103 for the 46 and 31 degree combination cutter. The 60 degree cutter is Neway cutter #101. The tapered pilots required are; Neway #100-1/4-1 for the .249 (6.325 mm) exhaust guide, and Neway #100-1/4 for the .250 (6.35 mm) intake guide. Consult the cutter's complete procedure guide for additional information. NOTE: The valve seats are cast into the engine block at a slight angle on the LEV engines. When reconditioning valve seats on the LEV engine, the seat cutter will make simultaneous contact with the seat and the aluminum portion of the engine block. There is no detrimental effect to performance or life of the valve seat or block from the procedure if done correctly. First, use the 60 degree cutter to cut the bottom narrowing/angle. The more of bottom narrowing that is removed the higher the contact surface will be on the valve face (closer to the margin diagram 46). Second, use the 31 degree cutter to cut the top narrowing/angle. The more of top narrowing that is removed the lower the contact surface will be on the valve face (away from the margin diagram 47). Lastly, use the 46 degree cutter to cut the middle angle which is where the valve will contact the valve seat (diagram 48). Consult the specifications pages for specific valve seat width dimensions by engine model. BOTTOM NARROWING CUTTER

TOP NARROWING CUTTER 150

SEAT CUTTER

310

460 FINALCUT

600 BOTTOM NARROWING

SEAT

SEAT

46

48

47

Valve Lifters The valve lifters on some engines are different lengths. The shorter lifter is installed in the intake position and the longer lifter is installed in the exhaust position. When removing, mark the lifters to install the lifter in the same position as it was removed from.

Oversize Valve Guides (Pre-emmisionized Engines) The valve guides are permanently installed in the cylinder block. If they get worn excessively, they can be reamed oversize to accommodate a 1/32" (.793 mm) oversize valve stem. The guides should be reamed oversize with a straight shanked hand reamer or low speed drill press. Refer to the "Table of Specifications" (Chapter 10) to determine the correct oversize dimension. Reamers are available through your local Tecumseh parts supplier. Consult the tool section in Chapter 11 for the correct part numbers. The upper and lower valve spring caps must be redrilled to accommodate the oversize valve stems. After oversizing the valve guides, the valve seats must be recut to align the valve seat to the valve guide.

CRANKCASE BREATHERS TUBE

The breather element and case can be cleaned using cleaning solvent. Make sure the small drain hole or holes are clean and installed facing down, so as to allow oil to return back into the crankcase.

Top Mounted Breather This type of breather is mounted in the top and rear of the cylinder block in vertical shaft engines. The check valve allows positive pressure to be vented through the element and out the tube. Some engines have the breather tube connected to the air cleaner assembly (diag. 49). 86

CHECK VALVE ELEMENT BAFFLE OIL RETURN

PRESSURE OUT

49

Late production top mounted breathers use the rubber boot and breather tube as a push in design. Mark or note the location of the breather tube. Use a large flat blade screwdriver to pry the boot up and lift the breather assembly out. Be careful not to drop the breather body out of the rubber boot when removing (diag. 50). A new breather tube boot is recommended for replacement to assure proper crankcase seal. Apply engine oil to the breather tube boot and push the breather in until the top shoulder of the boot contacts the crankcase. 50

Side Mounted Breather

COVER GASKET

This type of breather mounts over the valve compartment and uses a reed style check valve. Most horizontal shaft engines use this style of breather. The filter element is held in place by a small barb in the cover. To remove the filter, insert a knife blade between the filter element and the barb, and depress the filter element (diag. 51).

GASKET BODY REED

Some engine models have two gaskets installed next to the cylinder block. If two gaskets were originally installed, replace them using two gaskets (diag. 52).

BODY

FILTER

DRAIN HOLE

GASKET COVER

TUBE

51

Integral Breather Some ECV engines are equipped with breathers that are part of the cylinder block. Venting is accomplished through passages drilled in the block to route the air flow to the outside (diag. 53).

GASKET

52

BAFFLE

COVER

RETURN HOLE

COVER PLATE

ONE WAY DISC VALVE GASKET

IDENTIFICATION PLATE

WELCH PLUG

ONE WAY DISC VALVE RETURN HOLE

BAFFLE

53

CYLINDER COVER, OIL SEAL, AND BEARING SERVICE Cylinder Cover The following procedures, except oil seal replacement, require engine disassembly. See "Disassembly Procedure" in this chapter. Clean and inspect the cover, look for wear and scoring of the bearing surfaces. Measure the bearing surface diameters using a micrometer and check the specifications for worn or damaged parts. Replace as necessary. When reinstalling the cover, apply a drop of Loctite 242 to the cover screw threads and re-torque to the recommended specification. Always use new oil seals and gaskets after disassembly.

87

Oil Seal Service NOTE: BEFORE REMOVING THE OIL SEAL, CHECK TO SEE IF THE SEAL IS RAISED OR RECESSED. WHEN INSTALLING A NEW OIL SEAL, TAP IT INTO POSITION GENTLY UNTIL IT IS SEATED INTO ITS BOSS. SOME SEALS ARE NOT POSITIONED FLUSH TO THE CYLINDER COVER. ATTEMPTING TO INSTALL THE SEAL TOO FAR IN CAN CAUSE DAMAGE TO THE OIL SEAL AND ENGINE.

OIL SEAL REMOVER TOOL: POSITIONED FOR REMOVAL OF OIL SEAL OIL SEAL

If the crankshaft is removed from the engine, remove the old oil seals by tapping them out with a screwdriver or punch from the inside. If the crankshaft is in place, remove the seal by using the proper oil seal puller (diag. 54).

54 OIL SEAL DRIVER 670272

Select the proper seal protector and driver from the tool list in Chapter 11 to install a new oil seal. Place the oil seal over the protector (spring side of seal faces inward) and place it over the crankshaft. Drive the seal into position using the universal driver part no. 670272. The seal protector will insure that the seal is driven in to the proper depth (diag. 55).

OIL SEAL

OIL SEAL DRIVER PROTECTOR

CRANKSHAFT BEARING SERVICE

55

Ball Bearing Service (H40-HM100 engines) To remove the ball bearing from the cylinder cover, the bearing locks will have to be rotated out of the way. First loosen the locking nuts with a socket. Turn the retainer bolts counterclockwise to the unlocked position with a needle nose pliers (diag. 56). The flat side of the retainer will face away from the bearing in the unlocked position (diag. 57).

UNLOCKED

When reinstalling the locks, the flat side must face the bearing while the locking nuts should be torqued to 15-22 inch pounds (1.695 - 2.486 Nm).

LOCKED

To remove a ball bearing from the crankshaft, use a bearing splitter and a puller (diag. 58). When installing the ball bearing to the crankshaft, the bearing must be heated by either using a hot oil bath or heat lamp to expand the bearing. This will allow the bearing to slide on the crankshaft with no interference fit. Be careful to use adequate protection handling the hot ball bearing. The bearing and the thrust washer must seat tightly against the crankshaft gear.

P.T.O. BALL BEARING

INTERIOR OF COVER

FLAT

TURN COUNTERCLOCKWISE TO UNLOCK

BALL BEARING

FLAT

56

TURN CLOCKWISE TO LOCK

EXTERIOR OF COVER

57

PULLER

BEARING SPLITTER

58 88

COUNTERBALANCE SERVICE To correctly align the Ultra-Balance® system, rotate the piston to top dead center (TDC) and insert the counterbalance shaft into its boss in the cylinder block with the arrow on the gear pointing toward the crankshaft.

DRIVE GEAR

GOVERNOR

Slide the drive gear on the crankshaft, making sure the drive gear is located on the crankshaft key and that the arrow on the drive gear is aligned with the arrow on the gear on the counterbalance shaft (diag. 59 & 60).

CAMSHAFT

FLANGE

59

KEYWAY COUNTER BALANCE SHAFT

DRIVE GEAR

60

FLYWHEEL SERVICE POLYPROPYLENE PORTION OF FLYWHEEL

Some Tecumseh engines have polypropylene fans that are replaceable. A damaged fan can be replaced by tapping on the outside portion of the fan until it separates from the iron portion of the flywheel (diag. 61). A new fan may be installed by heating the polypropylene fan in a pan of boiling water. Suspend the fan off the bottom of the pan while heating. Using adequate protection, install the hot fan to the flywheel. Make sure the fan locators fit into the hub area of the flywheel. Flywheel magnets are factory installed and permanently bonded to the flywheel. If the magnets are damaged or lose their magnetic strength, the flywheel must be replaced.

IRON WHEEL

61

89

CHAPTER 10 ENGINE SPECIFICATIONS

The engine specifications listed on the following pages include tolerances that are considered acceptable to achieve normal engine operation. Observed values inside the listed tolerance range are satisfactory and require no adjustments.

90

FOUR CYCLE TORQUE SPECIFICATIONS The torque specifications listed in this chart are to be used for replacing components after disassembly, not for checking an existing engine bolt torque. Checking a torque value on a new or used engine may be lower due to torque relaxation that occurs on all engines from thermal expansion and contraction. However, sufficient clamping force exists and a re-torque is not necessary.

Lo catio n

in. lb s. ft. lb s.

Nm

ALL TVXL TVS

ALL TNT

ALL ECV

ALL LAV

H, V, HH, VH 30-40

HSSK HS

TVM HSK 125, H50140 60

X

Cyl. He ad Bo lts

200

16.5 22.5

X

X

X

X

X

X

Co nn. Ro d Bo lts

105

8.5

11.5

X

X

X

X

X

X

Co nn. Ro d Bo lts

170

14

19

Co nn. Ro d Bo lts

210

17.5

24

Cyl. Co ve r o r Flang e

115

9.5

13

Cyl. Co ve r o r Flang e (Po we rlo k)

125

10.5

14

Flywhe e l Nut (Aluminum)

450

37.5

51

Flywhe e l Nut

475

40

54

Flywhe e l Nut (Cast iro n)

550

46

62

Flywhe e l Nut

630

52.5

71

Flywhe e l Nut Ext. Ig n.

700

58

79

Sp ark Plug

250

21

28.5

X

X

X

X

Ig n. Mo unting (Dire ct to Cylind e r)

45

4

5

X

X

X

X

Ig n. Mo unting (Dire ct to Cylind e r)

90

7.5

10

Ig n. Mo unting (Stud to Cylind e r)

35

3

4

X

X

Ig n. Mo unting (to Stud )

45

4

5

X

X

Intake Pip e to Cylind e r

95

8

11

X

X

Intake Pip e to Cylind e r

110

9

11.5

X

X

Intake Pip e to Cylind e r

120

10

13.5

X

X

Carb ure to r to Intake Pip e

70

6

8

Carb . Ad ap te r to Cylind e r

85

7

9.5

X

X

X

X

X

X

X

X

X

V50 V60 V70

X

VM TVM & TVXL HMSK HH, HSK 170, HMXL VH LEV H70 195,220 HM 50-70 VSK

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X X

X

X

X

X

X X

X

X

X

X X

X

X

X X

X

X

X

X X

X

X

X

X

X

X

X

X

X

X

X

X

X X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X X

X

X X

X

X

X X

X

X

X

X

X

X

91

FOUR CYCLE TORQUE SPECIFICATIONS - CONTINUED The torque specifications listed in this chart are to be used for replacing components after disassembly, not for checking an existing engine bolt torque. Checking a torque value on a new or used engine may be lower due to torque relaxation that occurs on all engines from thermal expansion and contraction. However, sufficient clamping force exists and a re-torque is not necessary.

Lo catio n

in. lb s. ft. lb s. Nm

ALL TVXL TVS

ALL TNT

ALL ECV

ALL LAV

H, V, HH, VH 30-40

HSSK HS

TVM HSK, V50 125, H50- V60 140 60 V70

V80 VM TVM & TVXL 170, HMSK HH, HSK 195, HMXL VH LEV H70 220 HM 50-70 VSK

Muffle r Mo unting Sho uld e r Scre w

100

8.5

11.5

X

X

X

Muffle r Mo unting No Sho uld e r Scre w

20

2

2.5

X

X

X

Muffle r Mo unting (Pancake )

37.5

3

4

Muffle r Mo unting (Lo ck Tab s)

72.5

6

8

X

Muffle r Mo unting (HTL)

87.5

7.5

10

X

Muffle r Mtg .

120

10

13

Muffle r Mtg . Flang e d

80

6.5

9

Muffle r Mtg . Sho uld e r Bo lt

110

9

12.5

Mag ne to Stato r To Cylind e r

65

5.5

7.5

X

X

X

X

X

X

22.5

2

2.5

X

X

X

X

X

X

Re co il Starte r (To p Mo unt)

50

4

5.5

X

X

X

X

X

X

X

X

X

Re co il Starte r (Sid e Mo unt Plastic)

85

7

9.5

X

X

X

Re co il Starte r (Sid e Mo unt Me tal)

60

5

7

X

X

X

5.5

7.5

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Re co il Starte r To p Mo unt & 8-32 Thre ad Fo rming

Ele ctric Starte r To Cylind e r

65

Ele ctric Starte r To Cylind e r

95

8

11

Ele ctric Starte r To Cylind e r

155

13

17.5

92

X X

X X

X

X

X

X

X

X

X

X

X

X

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X

ENGINE SPECIFICATIONS STANDARD POINT IGNITION All models have point setting of .020" (.508 mm), spark plug gap of .030" (.762 mm), valve seat angle of 460. All U.S. dimensions are in inches.

SPECIFICATIONS

LAV25, LAV30 TVS75-90 Prior to 8/1987, H25, H30-1982 & Prior Me tric U.S. mm

H 30 (1983 Serial no.) Me tric U.S. mm

LAV35, H35 (1982 & prior) Me tric U.S. mm

H 35 (1983 Serial no.) Me tric U.S. mm

E C V 100 Me tric U.S. mm

Displacement (in³) (cc)

7.75

127.02

9.06

148.50

9.06

148.50

9.52

156.03

9.98

163.57

Stroke

1.844

46.838

1.844

46.838

1.844

46.836

1.938

49.225

1.844

46.838

Bore

2.3125 2.3135

58.738 58.763

2.5000 2.5010

63.5 63.525

2.5000 2.5010

63.5 63.525

2.5000 2.5010

63.5 63.525

2.6250 2.6260

66.675 66.700

Timing Dim. B.T.D.C.

0.065

1.651

0.035

.889

0.065

1.651

0.035

.889

0.035

.889

Valve Clearance

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

Valve Seat Width Exhaust

.035 .045

.889 1.143

.035 .045

.889 1.143

.035 .045

.889 1.143

.035 .045

.889 1.143

.035 .045

.889 1.143

Valve Guide Oversize Dim.

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

Crankshaft End Play

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

Crankpin Journal Dia.

.8610 .8615

21.869 21.882

.8610 .8615

21.869 21.882

.8610 .8615

21.869 21.882

.9995 1.0000

25.387 25.400

.8610 .8615

21.869 21.882

Crankshaft Mag. Main Brg. Dia.

.8735 .8740

22.187 22.200

.9985 .9990

25.362 25.375

.8735 .8740

22.187 22.200

.9985 .9990

25.362 25.375

.8735 .8740

22.187 22.200

Crankshaft P.T.O. Main Brg. Dia.

.8735 .8740

22.187 22.200

.8735 .8740

22.187 22.200

.8735 .8740

22.187 22.200

.9985 .9990

25.362 25.375

.8735 .8740

22.187 22.200

Camshaft Journals

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

Camshaft Bearings Cylinder & Cover / Flange

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.712

.4999 .5005

12.675 12.712

.4999 .5005

12.675 12.712

.4999 .5005

12.675 12.712

Connecting Rod Diameter Crank Bearing

.8620 .8625

21.895 21.908

.8620 .8625

21.895 21.908

.8620 .8625

21.895 21.908

1.0005 1.0010

25.413 25.425

.8620 .8625

21.895 21.908

Piston Diameter Bottom Of Skirt

2.3092 2.3100

58.654 58.674

2.4952 2.4960

63.378 63.398

2.4952 2.4960

63.378 63.398

2.4952 2.4960

63.378 63.398

2.6202 2.6210

66.553 66.573

Piston Pin Diameter

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.0005 .0035

.013 .089

.0005 .0035

.013 .089

.0005 .0035

.013 .089

.0005 .0035

.013 .089

.001 .004

.025 .102

.0025 .0043

.064 .109

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.007 .017 .8755 .8760

.178 .432 22.238 22.250

.007 .017 1.0005 1.0010

.178 .432 25.413 25.425

.007 .017 .8755 .8760

.178 .432 22.238 22.250

.007 .017 1.0005 1.0010

.178 .432 25.413 25.425

.007 .017 .8755 .8760

.178 .432 22.238 22.250

.8755 .8760

22.238 22.250

.8755 .8760

22.238 22.250

.8755 .8760

22.238 22.250

1.0005 1.0010

25.413 25.425

.8755 .8760

22.238 22.250

Intake

Ring Groove Side Clearance 1st & 2nd Comp. Ring Groove Side Clearance Bottom Oil Piston Skirt Clearance Ring End Gap Cylinder Main Brg. Cylinder Cover / Flange Main Bearing Diameter

93

ENGINE SPECIFICATIONS STANDARD POINT IGNITION (CONT.) All models have point setting of .020" (.508 mm), spark plug gap of .030" (.762 mm), valve seat angle of 460. All U.S. dimensions are in inches.

SPECIFICATIONS

T N T 100 Me tric U.S. mm

V40-V40B, V H 40, H 40, H H 40 Me tric U.S. mm

Displacement (in³) (cc)

9.98

163.57

11.04

180.95

10.49

Stroke

1.844

46.838

2.250

57.15

Bore

2.6250 2.6260

66.675 66.700

2.5000 2.5010

Timing Dim. B.T.D.C.

0.035

.889

Valve Clearance

.004 .008

E C V 105 Me tric U.S. mm

ECV110 Me tric U.S. mm

171.93

10.5

172.10

11.5

188.49

1.938

49.23

1.938

49.23

1.938

49.23

63.500 63.525

2.6250 2.6260

66.675 66.700

2.6250 2.6260

66.675 66.700

2.7500 2.7510

69.85 69.88

0.050

1.27

0.035

.889

0.035

.889

0.035

.889

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.035 .045

.889 1.143

.042 .052

1.067 1.321

.035 .045

.889 1.143

.035 .045

.889 1.143

.035 .045

.889 1.143

Valve Guide Oversize Dim.

.2807 .2817

7.130 7.155

.3432 .3442

8.717 8.743

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

Crankshaft End Play

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

Crankpin Journal Dia.

.8610 .8615

21.869 21.882

1.0615 1.0620

26.962 26.975

.9995 1.0000

25.387 25.400

.9995 1.0000

25.387 25.400

.9995 1.0000

25.387 25.400

Crankshaft Mag. Main Brg. Dia.

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9990 .9995

25.375 25.387

Crankshaft P.T.O. Main Brg. Dia.

.8735 .8740

22.187 22.200

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

Camshaft Journals

.4975 .4980

12.637 12.649

.6230 .6235

15.824 15.837

.4975 .4980

12.637 12.649

.4975 .4980

25.413 25.425

.4975 .4980

25.413 25.425

Camshaft Bearings Cylinder & Cover / Flange

.4999 .5005

12.675 12.713

.6245 .6255

15.862 15.888

.4999 .5005

12.675 12.712

.4999 .5005

12.675 12.712

.4999 .5005

12.675 12.712

Connecting Rod Diameter Crank Bearing

.8620 .8625

21.895 21.908

1.0630 1.0635

27.000 27.013

1.0005 1.0010

25.413 25.425

1.0005 1.0010

12.637 12.649

1.0005 1.0010

12.637 12.649

Piston Diameter Bottom Of Skirt

2.6202 2.6210

66.553 66.573

2.4945 2.4950

63.360 63.373

2.6202 2.6210

66.553 66.573

2.6202 2.6210

66.553 66.573

2.7450 2.7455

69.723 69.736

Piston Pin Diameter

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

Valve Seat Width

94

LAV40, TVS105, H S 40, T V X L 105 Me tric U.S. mm

Intake Exhaust

Ring Groove Side Clearance 1st & 2nd Comp. Ring Groove Side Clearance Bottom Oil

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

Piston Skirt Clearance

.0040 .0058

.102 .147

.0055 .0070

.140 .178

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.0045 .0060

.114 .152

Ring End Gap

.007 .017

.178 .432

.007 .017

.178 .432

.007 .017

.178 .432

.007 .017

.178 .432

.007 .017

.178 .432

Cylinder Main Brg.

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

Cylinder Cover / Flange Main Bearing Diameter

.8755 .8760

22.238 22.250

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

ENGINE SPECIFICATIONS STANDARD POINT IGNITION All models have point setting of .020" (.508 mm), spark plug gap of .030" (.762 mm), valve seat angle of 460. All U.S. dimensions are in inches.

SPECIFICATIONS

LAV50, TVS120, H S 50 Me tric U.S. mm

T N T 120 E C V 120 Me tric U.S. mm

V 50, VH50*,TVM125 H 50, H H 50* Me tric U.S. mm

V 60, VH60*,TVM140 H 60, H H 60* Me tric U.S. mm

V70, VH70*, VM70 H 70, H H 70* Me tric U.S. mm

Displacement (in³) (cc)

12.04

197.34

12.04

197.34

12.18

199.63

13.53

221.76

15.04

246.51

Stroke

1.938

49.23

1.938

49.23

2.25

57.15

2.5

63.5

2.532

64.31

Bore

2.8120 2.8130

71.425 71.450

2.8120 2.8130

71.425 71.450

2.6250 2.6260

66.675 66.700

2.6250 2.6260

66.675 66.700

2.7500 2.7510

69.85 69.88

Timing Dim. B.T.D.C.

0.035

.889

0.035

.889

0.080

2.032

0.080

2.032

0.080

2.032

Valve Clearance

.004 .010 .035 .045

.102 .254 .889 1.143

.004 .010 .035 .045

.102 .254 .889 1.143

.008 .012 .042 .052

.203 .305 1.067 1.321

.008 .012 .042 .052

.203 .305 1.067 1.321

.008 .012 .042 .052

.203 .305 1.067 1.321

Valve Guide Oversize Dim.

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.3432 .3442

8.717 8.743

.3432 .3442

8.717 8.743

.3432 .3442

8.717 8.743

Crankshaft End Play

.005 .027

.127 .686

.005 .027

.127 .027

.005 .027 no te C

.127 .027

.005 .027 no te C

.127 .027

.005 .027 no te C

.127 .027

Crankpin Journal Dia.

.9995 1.0000

25.387 25.400

.9995 1.0000

25.387 25.400

1.0615 1.0620

26.962 26.975

1.0615 1.0620

26.962 26.975

1.1860 1.1865

30.124 30.137

Crankshaft Mag. Main Brg. Dia.

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

Crankshaft P.T.O. Main Brg. Dia.

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

Camshaft Journals

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

Camshaft Bearings Cylinder & Cover / Flange

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.712

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

Connecting Rod Diameter Crank Bearing

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0630 1.0635

27.000 27.013

1.0630 1.0635

27.000 27.013

1.1880 1.1885

30.175 30.188

Piston Diameter Bottom Of Skirt

2.8072 2.8080

71.303 71.323

2.8072 2.8080

71.303 71.323

2.6210 2.6215

66.573 66.586

2.6210 2.6215

66.573 2.6215

2.7450 2.7455

69.723 69.736

Piston Pin Diameter

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.6247 .6249

15.867 15.872

.6247 .6249

15.867 15.872

.6247 .6249

15.867 15.872

.002 .005

.051 .127

.002 .005

.051 .127

.002 .004

.051 .102

.002 .004

.051 .102

.002 .003

.051 .076

.001 .004

.025 .102

.001 .004

.025 .102

.002 .004

.051 .102

.002 .004

.051 .102

.001 .003

.025 .076

Piston Skirt Clearance

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.089 .127

.178 .432

.007 .017

.178 .432

.254 .508

.254 .508

.0045 .0060 no te B .010 .020

.114 .152

.007 .017

.0035 .0050 no te A .010 .020

.089 .127

Ring End Gap

.0035 .0050 no te A .010 .020

Cylinder Main Brg.

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

Cylinder Cover / Flange Main Bearing Diameter

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

Valve Seat Width

Intake Exhaust

Ring Groove Side Clearance 1st & 2nd Comp. Ring Groove Side Clearance Bottom Oil

.254 .508

* Notes: (A) VH50, 60 .0015/.0055 (.038/.140mm) (B) VH70 .0038/.0073 (.097/.185 mm) (C) VH, HH50-70 Models .003/.031 (.762/.787 mm)

95

ENGINE SPECIFICATIONS STANDARD POINT IGNITION (Cont.) All models have point setting of .020" (.508 mm), spark plug gap of .030" (.762 mm), valve seat angle of 460. All U.S. dimensions are in inches.

SPECIFICATIONS

TVM170, HM70 Me tric U.S. mm

V80, VM80*, H70*, HM80* Me tric U.S. mm

VM80*, TVM195, HM80*, HHM80 Me tric U.S. mm

VM100, HM100 Me tric U.S. mm

TVM220, HM100 Me tric U.S. mm

Displacement (in³) (cc)

17.17

281.42

18.65

305.67

19.43 no te A

318.46

20.2

333.08

21.82

357.63

Stroke

2.532

64.31

2.532

64.31

2.532

64.31

2.532

64.31

2.532

64.31

Bore

2.9375 2.9385

74.613 74.638

3.0620 3.0630

77.775 77.800

3.1250 3.1260

79.375 79.400

3.1870 3.1880

80.950 80.975

3.3120 3.3130

84.125 84.150

Timing Dim. B.T.D.C.

0.090

2.286

0.090

2.286

0.090

2.286

0.090

2.286

0.090

2.286

Valve Clearance

.008 .012

.203 .305

.008 .012

.203 .305

.008 .012

.203 .305

.008 .012

.203 .305

.008 .012

.203 .305

.042 .0938

1.067 2.383

1.067 2.383

.042 .0938

1.067 2.383

.042 .0938

1.067 2.383

.042 .0938

1.067 2.383

Valve Guide Oversize Dim.

.3432 .3442

8.717 8.743

.042 .0938 no te B .3432 .3442

8.717 8.743

.3432 .3442

8.717 8.743

.3432 .3442

8.717 8.743

.3432 .3442

8.717 8.743

Crankshaft End Play

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

Crankpin Journal Dia.

1.1860 1.1865

30.124 30.137

1.1860 1.1865

30.124 30.137

1.1860 1.1865

30.124 30.137

1.1860 1.1865

30.124 30.137

1.1860 1.1865

30.124 30.137

Crankshaft Mag. Main Brg. Dia.

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

Crankshaft P.T.O. Main Brg. Dia.

1.1870 1.1875

30.150 30.163

1.1870 1.1875

30.150 30.163

1.1870 1.1875

30.150 30.163

1.1870 1.1875

30.150 30.163

1.1870 1.1875

30.150 30.163

Camshaft Journals

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

Camshaft Bearings Cylinder & Cover / Flange

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

Connecting Rod Diameter Crank Bearing

1.1880 1.1885

30.175 30.188

1.1880 1.1885

30.175 30.188

1.1880 1.1885

30.175 30.188

1.1880 1.1885

30.175 30.188

1.1880 1.1885

30.175 30.188

Piston Diameter Bottom Of Skirt

2.9325 2.9335

74.486 74.511

3.0575 3.0585

77.661 77.686

3.1195 3.1205

79.235 79.261

3.1815 3.1825

80.810 80.836

3.3090 3.3105

84.049 84.087

Piston Pin Diameter

.6247 .6249

15.867 15.872

.6247 .6249

15.867 15.872

.6247 .6249

15.867 15.872

.6873 .6875

17.457 17.463

.6873 .6875

17.457 17.463

Ring Groove Side Clearance 1st & 2nd Comp. Ring Groove Side Clearance Bottom Oil

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

Piston Skirt Clearance

.004 .006

.102 .152

.0035 .0055

.089 .140

.0045 .0065

.114 .175

.0045 .0065

.114 .175

.0015 .0040

.038 .102

Ring End Gap

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

Cylinder Main Brg.

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

Cylinder Cover / Flange Main Bearing Diameter

1.1890 1.1895

30.201 30.213

1.1890 1.1895

30.201 30.213

1.1890 1.1895

30.201 30.213

1.1890 1.1895

30.201 30.213

1.1890 1.1895

30.201 30.213

Valve Seat Width

Intake Exhaust

* Check to determine bore size Notes: (A) VM & HM80 - Displacement 19.41 (318 cc), (B) H70 Exhaust Valve Seat Width .052"

96

SOLID STATE AND EXTERNAL IGNITION

All solid state models have air gap settings of .0125" (.3175 mm), spark plug gap of .030" (.762 mm), valve seat angle of 460. All U.S. dimensions are in inches.

T V S 75 Prior to 8/87 Me tric U.S. mm

T V S 90 Me tric U.S. mm

U.S.

Me tric mm

V 40, T V S 105, H S 40 Me tric U.S. mm

Displacement (in³) (cc)

7.75

127.02

9.06

148.50

9.52

156.03

10.49

171.93

9.98

163.57

Stroke

1.844

46.838

1.844

46.838

1.938

49.225

1.938

49.225

1.844

46.838

Bore

2.3125 2.3135

58.738 58.763

2.500 2.501

63.500 63.525

2.500 2.501

63.500 63.525

2.625 2.626

66.675 66.700

2.625 2.626

66.675 66.700

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.035 .045

.889 1.143

.035 .045

.889 1.143

.035 .045

.889 1.143

.035 .045

.889 1.143

.035 .045

.889 1.143

Valve Guide Oversize Dim.

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

Crankshaft End Play

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

Crankpin Journal Dia.

.8610 .8615

21.869 21.882

.8610 .8615

21.869 21.882

.9995 1.0000

25.387 25.400

.9995 1.0000

25.387 25.400

.8610 .8615

21.869 21.882

Crankshaft Mag. Main Brg. Dia.

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

Crankshaft P.T.O. Main Brg. Dia.

.8735 .8740

22.187 22.200

.8735 .8740

22.187 22.200

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.8735 .8740

22.187 22.200

Camshaft Journals

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

Camshaft Bearings Cylinder & Cover / Flange

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

Connecting Rod Diameter Crank Bearing

.8620 .8625

21.895 21.908

.8620 .8625

21.895 21.908

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

.8620 .8625

21.895 21.908

Piston Diameter Bottom Of Skirt

2.3092 2.3100

58.654 58.674

2.4952 2.4960

63.738 63.398

2.4952 2.4960

63.738 63.398

2.6202 2.6210

66.553 66.573

2.6202 2.6210

66.553 66.573

Piston Pin Diameter

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

Ring Groove Side Clearance 1st & 2nd Comp.

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

Ring Groove Side Clearance Bottom Oil

.0005 .0035

.013 .089

.0005 .0035

.013 .089

.0005 .0035

.013 .089

.001 .004

.025 .102

.001 .004

.025 .102

Piston Skirt Clearance

.0025 .0043

.064 .109

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.0040 .0058

.102 .147

Ring End Gap

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

Cylinder Main Brg.

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

Cylinder Cover / Flange Main Bearing Diameter

.8755 .8760

22.238 22.250

.8755 .8760

22.238 22.250

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

.8755 .8760

22.238 22.250

SPECIFICATIONS

Valve Clearance Valve Seat Width

Intake Exhaust

H 35

T V S 100, E C V 100, T N T 100 Me tric U.S. mm

97

SOLID STATE AND EXTERNAL IGNITION

All solid state models have air gap settings of .0125" (.3175 mm), spark plug gap of .030" (.762 mm), valve seat angle of 460. All U.S. dimensions are in inches.

SPECIFICATIONS

TVS/ TVXL115 57000 Series ONLY Me tric U.S. mm

T V S 105 56000 Series TVS/TVXL 115 57000 A & later Me tric U.S. mm

T V S 120 J & later HS50 H & later HSSK 50-55 N & later Me tric U.S. mm

LAV50,TVS120 HS50 G & earlier HSSK50 M & earlier Me tric U.S. mm

VH50, TVM125 H 50, H H 50 Me tric U.S. mm

Displacement (in³) (cc)

11.44

187.50

11.32

185.53

11.9

195.04

12.04

197.34

12.18

199.63

Stroke

1.844

46.838

1.844

46.838

1.938

49.23

1.938

49.23

2.250

57.15

Bore

2.812 2.813

71.425 71.450

2.795 2.796

70.993 71.018

2.795 2.796

70.993 71.018

2.812 2.813

71.425 71.450

2.625 2.626

66.675 66.700

Valve Clearance

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.008 .012

.203 .305

.035 .045

.889 1.143

.035 .045

.889 1.143

.035 .045

.889 1.143

.035 .045

.889 1.143

.042 .052

1.067 1.321

Valve Guide Oversize Dim.

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.2807 .2817

7.130 7.155

.3432 .3442

8.717 8.743

Crankshaft End Play

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

Crankpin Journal Dia.

.8610 .8615

21.869 21.882

.8610 .8615

21.869 21.882

.9995 1.000

25.387 25.400

.9995 1.000

25.387 25.400

1.0615 1.0620

26.962 26.975

Crankshaft Mag. Main Brg. Dia.

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

Crankshaft P.T.O. Main Brg. Dia.

.8735 .8740

22.187 22.200

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

Camshaft Journals

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.4975 .4980

12.637 12.649

.6230 .6235

15.824 15.837

Camshaft Bearings Cylinder & Cover / Flange

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

.6245 .6255

15.862 15.888

Connecting Rod Diameter Crank Bearing

.8620 .8625

21.895 21.908

.8620 .8625

21.895 21.908

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0630 1.0635

27.000 27.013

Piston Diameter Bottom Of Skirt

2.8072 2.8080

71.303 71.323

2.790 2.791

70.866 70.891

2.790 2.791

70.866 70.891

2.8072 2.8080

71.303 71.323

2.6212 2.6220

66.578 66.599

Piston Pin Diameter

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.5628 .5630

14.295 14.300

.6247 .6249

15.867 15.872

Ring Groove Side Clearance 1st & 2nd Comp.

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

Ring Groove Side Clearance Bottom Oil

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

Piston Skirt Clearance

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.0040 .0058

.102 .147

.0030 .0048

.076 .122

Ring End Gap

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

.010 .020

.254 .508

Cylinder Main Brg.

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

Cylinder Cover/Flange Main Bearing Diameter

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

Valve Seat Width

98

Intake Exhaust

SOLID STATE AND EXTERNAL IGNITION

All solid state models have air gap settings of .0125" (.3175 mm), spark plug gap of .030" (.762 mm), valve seat angle of 460. All U.S. dimensions are in inches.

SPECIFICATIONS

L E V 80

L E V 100

V S K 100

LEV115

L E V 120

U.S.

Me tric mm

U.S.

Me tric mm

U.S.

Me tric mm

U.S.

Me tric mm

U.S.

Me tric mm

Displacement (in³) (cc)

7.75

127.02

9.98

163.57

9.98

163.57

11.32

185.53

11.90

195.04

Stroke

1.844

46.838

1.844

46.838

1.844

46.838

1.844

46.838

1.938

49.23

Bore

2.311 2.312

58.750

2.625 2.626

66.675 66.700

2.625 2.626

66.675 66.700

2.795 2.796

70.993 71.018

2.795 2.796

70.993 71.018

Valve Clearance

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

.004 .008

.102 .203

Valve Seat Width Exhaust

.035 .045

.889 1.143

.066 .086

1.676 2.184

.066 .086

1.676 2.184

.066 .086

1.676 2.184

.066 .086

1.676 2.184

Valve Guide Oversize Dim.

.2505 N/A

6.363 N/A

.2505 N/A

6.363 N/A

.2505 N/A

6.363 N/A

.2505 N/A

6.363 N/A

.2505 N/A

6.363 N/A

Crankshaft End Play

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

.005 .027

.127 .686

Crankpin Journal Dia.

.8610 .8615

21.869 21.882

.9995 1.000

25.837 25.400

.9995 1.000

25.837 25.400

.9995 1.000

25.837 25.400

.9995 1.000

25.837 25.400

Crankshaft Mag. Main Brg. Dia.

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

Crankshaft P.T.O. Main Brg. Dia. Camshaft Journals

.8735 .8740 .4975 .4980

22.187 22.200 12.637 12.649

.9985 .9990 .4975 .4980

25.362 25.375 12.637 12.649

.9985 .9990 .4975 .4980

25.362 25.375 12.637 12.649

.9985 .9990 .4975 .4980

25.362 25.375 12.637 12.649

.9985 .9990 .4975 .4980

25.362 25.375 12.637 12.649

Camshaft Bearings Cylinder & Cover / Flange

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

.4999 .5005

12.675 12.713

Cam Journal Bushing End

.3725 .3730 no te A .376 .378 no te A .8620 .8625

9.462 9.474

9.462 9.474

N/A

N/A

N/A

N/A

25.413 25.425

25.451 25.464

25.413 25.425

25.413 25.425

2.309 2.310 .5628 .5630

58.649 58.674 14.295 14.300

2.620 2.622 .5628 .5630

66.548 66.599 14.295 14.300

1.0020 1.0025 no te B 2.620 2.622 .5628 .5630

.3725 .3730 no te A .376 .378 no te A 1.0005 1.0010

9.462 9.474

9.550 9.601

.3725 .3730 no te A .376 .378 no te A 1.0005 1.0010

9.462 9.474

21.895 21.908

.3725 .3730 no te A .376 .378 no te A 1.0005 1.0010

66.548 66.599 14.295 14.300

2.790 2.792 .5628 .5630

70.866 70.917 14.295 14.300

2.790 2.792 .5628 .5630

70.866 70.917 14.295 14.300

.0011 .0043

.028 .109

.005 Max.

.127

.005 Max.

.127

.005 Max.

.127

.005 Max.

.127

.001 .004

.025 .102

.0035 Max.

.089

.0035 Max.

.089

.0035 Max.

.089

.0035 Max.

.089

.0025 .0045 .005 .013 1.0005 1.0010

.064 .114 .127 .330 25.413 25.425

.003 .006 .005 .024 1.0005 1.0010

.076 .152 .127 .610 25.413 25.425

.003 .006 .005 .024 1.0005 1.0010

.076 .152 .127 .610 25.413 25.425

.003 .006 .005 .024 1.0005 1.0010

.076 .152 .127 .610 25.413 25.425

.003 .006 .005 .024 1.0005 1.0010

.076 .152 .127 .610 25.413 25.425

.8755 .8760

22.238 22.250

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

Intake

Cam Bushing Inside Diameter Connecting Rod Diameter Crank Bearing Piston Diameter Bottom Of Skirt Piston Pin Diameter Ring Groove Side Clearance 1st & 2nd Comp. Ring Groove Side Clearance Bottom Oil Piston Skirt Clearance Ring End Gap Cylinder Main Brg. Cylinder Cover/Flange Main Bearing Diameter

9.550 9.601

9.550 9.601

9.550 9.601

Note A - LEV's built after 10-99 have the new Exhaust MCR Camshaft which require the bushing. Note B - VSK100 - Connecting Rod Diameter is larger than LEV models.

99

SOLID STATE AND EXTERNAL IGNITION All solid state models have air gap settings of .0125" (.3175 mm), spark plug gap of .030" (.762 mm), valve seat angle of 460. All U.S. dimensions are in inches.

V70, VH70,H70, H S K 70, HH70, TVM170 (E) MODEL Me tric U.S. mm

TVM170 Models F & UP ), HM70 Models (E & up) Me tric U.S. mm

SPECIFICATIONS

H S K 60 VH60, TVM140, H 60, H H 60 Me tric U.S. mm

Displacement (in³) (cc)

13.53

221.76

15.04

246.51

17.17

281.42

17.17

281.42

19.43

318.46

Stoke

2.500

63.5

2.532

64.31

2.532

64.31

2.532

64.31

2.532

64.31

Bore

2.625 2.626

66.675 66.700

2.750 2.751

69.85 69.88

2.9375 2.9385

74.613 74.638

2.9375 2.9385

74.613 74.638

3.125 3.126

79.374 79.400

Valve Clearance

.008 .012

.203 .305

.008 .012

.203 .305

.008 .012

.203 .305

.008 .012

.203 .305

.008 .012

.203 .305

.042 .052

1.067 1.321

.042 .052

1.067 1.321

.042 .052

1.067 1.321

.042 .052

1.067 1.321

.042 .052

1.067 1.321

8.717 8.743 .127 .686

.3432 .3442 .005 .027

8.717 8.743 .127 .686

.3432 .3442 .007 .029

8.717 8.743 .178 .737

.3432 .3442 .007 .029

8.717 8.743 .178 .737

26.962 26.975 25.362 25.375

.3432 .3442 .005 .027 No te (A) 1.1862 1.1865 .9985 .9990

8.717 8.743 .127 .686

Crankshaft Mag. Main Brg. Dia.

.3432 .3442 .005 .027 No te (A) 1.0615 1.0620 .9985 .9990

30.129 30.137 25.362 25.375

1.1860 1.1865 .9985 .9990

30.124 30.137 25.362 25.375

1.3740 1.3745 1.3745 1.3750

34.900 34.912 34.912 34.925

1.3740 1.3745 1.3745 1.3750

34.900 34.912 34.912 34.925

Crankshaft P.T.O. Main Brg. Dia.

.9985 .9990

25.362 25.375

.9985 .9990

25.362 25.375

1.1870 1.1875

30.150 30.163

1.3745 1.3750

34.912 34.925

1.3745 1.3750

34.912 34.925

Camshaft Journals

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

Camshaft Bearings Cylinder & Cover / Flange

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

1.0630 1.0635

27.000 27.013

1.0630 1.0635

27.000 27.013

1.1880 1.1885

30.175 30.188

34.950 34.963

66.578 66.599

2.6212 2.6220 No te (E)

66.578 66.599

2.9325 2.9335

74.486 74.511

74.486 74.511

1.3760 1.3765 No te (F) 3.1195 3.1205

34.950 34.963

2.6212 2.6220 No te (D)

1.3760 1.3765 No te (F) 2.9325 2.9335

79.235 79.261

.6247 .6249

15.867 15.872

.6247 .6249

15.867 15.872

.6247 .6249

15.867 15.872

.6247 .6249

15.867 15.872

.6247 .6249

15.867 15.872

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.002 .005

.051 .127

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.0030 .0048 No te (B)

.076 .122

.0030 .0048 No te (C)

.076 .122

.004 .006

.102 .152

.004 .006

.102 .152

.0045 .0065

.114 .165

.010 .020 1.0005 1.0010

.254 .508 25.413 25.425

.010 .020 1.0005 1.0010

.254 .508 25.413 25.425

.010 .020 1.0005 1.0010

.254 .508 25.413 25.425

.010 .020 1.3765 1.3770

.254 .508 34.963 34.976

.010 .020 1.3765 1.3770

.254 .508 34.963 34.976

1.0005 1.0010

25.413 25.425

1.0005 1.0010

25.413 25.425

1.1890 1.1895

30.200 30.213

1.3765 1.3770

34.963 34.976

1.3765 1.3770

34.963 34.976

Valve Seat Width

Intake Exhaust

Valve Guide Oversize Dim. Crankshaft End Play Crankpin Journal Dia.

Connecting Rod Diameter Crank Bearing Piston Diameter Bottom Of Skirt Piston Pin Diameter Ring Groove Side Clearance 1st & 2nd Comp. Ring Groove Side Clearance Bottom Oil Piston Skirt Clearance Ring End Gap Cylinder Main Brg. Cylinder Cover/Flange Main Bearing Diameter

HM70 (Models ending in C) Me tric U.S. mm

HM70 (Models ending in D) Me tric U.S. mm

Notes: (A) VH, HH50-70 models .003/.031 (.762/.787 mm) (B) VH, HH50-60 .0015/.005 (.038/.140 mm) (C) VH, HH70 .0038/.0073 (.097/.185 mm) (D) VH, HH50-60 2.6235/2.6205 (66.637/66.561 mm) (E) VH, HH70 2.7462/2.7437 (69.754/69.69 mm) (F) After Serial Number 9274 1.3775/1.3780 (34.989/35.001 mm)

100

SOLID STATE AND EXTERNAL IGNITION (Cont.) All solid state models have air gap settings of .0125" (.3175 mm), spark plug gap of .030" (.762 mm), valve seat angle of 460. All U.S. dimensions are in inches.

SPECIFICATIONS

HMSK80 VM80*, TVM195 (A-K), HM80** Me tric U.S. mm

Displacement (in³) (cc)

19.43

318.46

19.43

318.46

21.82

357.63

21.82

357.63

Stroke

2.532

64.31

2.532

64.31

2.532

64.31

2.532

64.31

Bore

3.125 3.126 .008 .012

79.375 79.400 .203 .305

3.125 3.126 .008 .012

79.375 79.400 .203 .305

3.312 3.313 .008 .012

84.125 84.150 .203 .305

3.312 3.313 .008 .012

84.125 84.150 .203 .305

.042 .0938

1.067 2.383

.042 .0938

1.067 2.383

.042 .0938

1.067 2.383

.042 .0938

1.067 2.383

.3432 .3442 .007 .029

8.717 8.743 .178 .737

.3432 .3442 .007 .029

8.717 8.743 .178 .737

.3432 .3442 .007 .029

8.717 8.743 .178 .737

8.717 8.743 .178 .737

1.1860 1.1865 .9985 .9990 1.1870 1.1875

30.124 30.137 25.362 25.375 30.150 30.163

1.3740 1.3745 1.3745 1.3750 1.3745 1.3750

34.900 34.912 34.912 34.925 34.912 34.925

1.1860 1.1865 .9985 .9990 1.1870 1.1875

30.124 30.137 25.362 25.375 30.150 30.163

.3432 .3442 .007 .029 No te (B) 1.3740 1.3745 1.3745 1.3750 1.3745 1.3750

34.900 34.912 34.912 34.925 34.912 34.925

Camshaft Journals

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

.6230 .6235

15.824 15.837

Camshaft Bearings Cylinder & Cover / Flange

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

.6245 .6255

15.862 15.888

Connecting Rod Diameter Crank Bearing

1.1880 1.1885

30.175 30.188

1.3760 1.3765 No te (A)

34.950 34.963

1.1880 1.1885

30.175 30.188

1.3760 1.3765 No te (A)

34.950 34.963

Piston Diameter Bottom Of Skirt

3.1195 3.1205

79.235 79.261

3.1195 3.1205

79.235 79.261

3.3090 3.3105

84.049 84.087

3.3098 3.3108

84.069 84.094

Piston Pin Diameter

.6247 .6249

15.867 15.872

.6247 .6249

15.867 15.872

.6873 .6875

17.457 17.463

.6873 .6875

17.457 17.463

Ring Groove Side Clearance 1st & 2nd Comp.

.002 .005

.051 .127

.002 .005

.051 .127

.0015 .0035

.038 .039

.0015 .0035

.038 .039

Ring Groove Side Clearance Bottom Oil

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.001 .004

.025 .102

.0045 .0065 .010 .020 1.0005 1.0010

.144 .165 .254 .508 25.413 25.425

.0045 .0065 .010 .020 1.3765 1.3770

.144 .165 .254 .508 34.963 34.976

.0015 .0040 .010 .020 1.0005 1.0010

.038 .102 .254 .508 25.413 25.425

.0012 .0032 .010 .020 1.3765 1.3770

.030 .081 .254 .508 34.963 34.976

1.1890 1.1895

30.200 30.213

1.3765 1.3770

34.963 34.976

1.1890 1.1895

30.200 30.213

1.3765 1.3770

34.963 34.976

Valve Clearance Valve Seat Width

Intake Exhaust

Valve Guide Oversize Dim. Crankshaft End Play Crankpin Journal Dia. Crankshaft Mag. Main Brg. Dia. Crankshaft P.T.O. Main Brg. Dia.

Piston Skirt Clearance Ring End Gap Cylinder Main Brg. Cylinder Cover/Flange Main Bearing Diameter

HM80**, HM90, HMSK80-90, TVM195 (L & up), TVXL195 Me tric U.S. mm

TVM220 (A-F), HM100** Me tric U.S. mm

HMSK100, HMSK110 TVM220 (G & up), TVXL220, HM100** Me tric U.S. mm

* Check to detemine bore size Notes: (A) After Serial Number 9274 1.3775/1.3780 (34.989/35.001 mm) (B) TVM 220 Ultra Balance .002/.042 (.153/2.184 mm) ** Check to determine crankshaft bearing diameters

101

CHAPTER 11 EDUCATIONAL MATERIALS AND TOOLS AVAILABLE TECHNICIAN'S HANDBOOKS 692508 Covers the diagnosis and repair of Tecumseh 2-cycle engines. Except the TC Engine and TVS840. 692509 Covers the diagnosis and repair of the Tecumseh 4-cycle light/medium frame engines. 691462A Covers the diagnosis and repair of Tecumseh 4-cycle large frame engines. 691218 Covers the diagnosis and repair of Peerless® power train components. 694782 Contains technical information for the repair of the TC series, 2-cycle engines. 694988 Contains diagnosis and technical information for the repair of TVS840, HSK/HXL845/850, 2-cycle engines. 695244A Covers the diagnosis and repair of the OVRM/OVM/OHM/ OHV 4-cycle overhead valve engines. 695578 Covers the diagnosis and repair of the Vector Series, 4cycle engines. AVAILABLE FOREIGN TECHNICIAN'S HANDBOOKS 694732 Spanish This manual covers the following models: VH80, VH100, HH80, HH100, HH120, OH120-180 Model numbers are located on the engine shroud. 695555 Spanish Covers the diagnosis and repair of the Tecumseh 4-cycle light/medium frame engines. 695657 German Covers the diagnosis and repair of the Tecumseh 4-cycle light/medium frame engines. 695562 French Covers the diagnosis and repair of the Tecumseh 4-cycle light/medium frame engines. VIDEO PROGRAMS 695015 Carburetor Troubleshooting. Covers identification of carburetors used on Tecumseh engines and how to troubleshoot and repair them. VHS only. 695059 Understanding Tecumseh Ignition Systems. A basic program designed to give the small engine technician first hand knowledge of Tecumseh ignition systems so the technician can understand the system and perform repairs to it. VHS only. 695148 Teardown and reassembly of the 900 series transaxles. This video will show a complete step-by-step procedure for teardown and reassembly of the 900, 910 and 920 series transaxles.

102

695185 Electrical Troubleshooting. This video training program will assist the small engine technician in the proper procedures for troubleshooting electrical systems on outdoor power equipment. 695285 An in-depth look at the 800 series transaxles. Detailing the teardown and reassembly procedures for the 800, 801 and 820 transaxles. SPECIAL BOOKLETS INSTRUCTIONAL GUIDE 692738 Assists in the use and understanding of the Tecumseh Master Parts Manual. Illustrates time saving features incorporated into the manual. Explains new carburetor parts breakdown format. 4-CYCLE ENGINE FAILURE ANALYSIS 695590 This booklet is designed as a tool for the average technician to correctly assess the cause of failure. CARBURETOR TROUBLESHOOTING BOOKLET 695907 This booklet is designed as a quick reference to carburetion problems and related repair procedures. IGNITION SYSTEMS TROUBLESHOOTING BOOKLET 694903 This booklet contains information on the identification, possible problems and related repair procedures of Tecumseh Ignition Systems. SPECIAL TOOLS BOOKLET 694862 This booklet depicts all specialty tools offered by Tecumseh which can be used on 2 and 4 cycle engines and Peerless units. QUICK REFERENCE CHART BOOKLET 695933 This booklet contains the quick reference information found on Tecumseh wall charts. This booklet is designed to be used as a work bench quick reference guide when servicing Tecumseh engines and motion drive systems. TESTER BOOKLETS 694529 Test procedures for Tecumseh electrical components using Graham-Lee Tester 31-SM or 31-SMX-H. 694530 Test procedures for Tecumseh electrical components using Merco-O-Tronic Tester 9800. (Tests are similar for 98, 98A and 79.)

OIL SEAL DRIVER

FLYWHEEL KNOCK-OFF TOOL

No. 670272 - Oil Seal Driver. Used with all oil seal protector-drivers to drive the seal into position. No. 670103 - Knock-off tool (right hand) (7/16"). OIL SEAL PROTECTOR / INSTALLER Consult the specification chart or measure the shaft diameter to determine the correct tool. 670260 - Seal Protector PTO & Magneto w/dia. of 1.187”-1.875” HH80-120, VH80-120, OH120-180, VM70-100, HM70-100 670261 - Seal Protector PTO & Magneto w/dia. of .811”-.815” External ignition lightweight engines 670262 - Seal Protector PTO & Magneto w/dia. of .749”-.750” Standard ignition lightweight engines 670308 - Seal Adaptor PTO & Magneto on HM70-100, TVM170-220, OVM120, TVXL195-220, HMSK100, w/shaft dia. of 1.3745"-1.3750" 670309 - Seal Protector PTO & Magneto on HM70-100, TVM170-220, OVM120, TVXL195-220, HMSK100, w/shaft dia. of 1.3745"-1.3750" 670310 - Seal Protector / Installer PTO & Magneto on HM70-100, TVM170-220, OVM120, TVXL195-220, HMSK100, w/shaft dia. of 1.3745"-1.3750" 670263 - Seal Protector Driver Oil seal on extended camshaft medium frame engines w/dia. of .6248”-.6253” Extended 5/8" camshaft medium frame engines 670264 - Seal Protector Driver Oil seal on 1/2" extended camshaft small frame engines w/dia. of .4998”-.5001” 670272 - Seal Driver Used with all oil seal installers 670277 - Seal Protector Oil seal on 8-1/2:1 1/2” shaft on light weight vertical crankshaft engines 670292 - Seal Protector and Installer Assy. Includes 670265, 670266, & 670267 (I.D. 1.002", 1.052" and 1.050") for V70, VM70-100, H70, HM70-100, V50-70, H50-70, HS40-50, LAV40-50, TVS105-120, TNT120 670293 - Seal Protector and Installer Assy. Includes 670268 & 670269 (I.D. .875" and .935") H30-35, LAV30-35, TNT100, TVS75-90, ECV90-100 670294 - Seal Protector and Installer Assy. Includes 670273 & 670274 (I.D. .680" and 1.005") AH520 & AH600 with one piece oil seal 670330 - Seal Protector / Installer OHV13.5-17 w/ 1-1/2” extended camshaft 670335 - Seal Protector / Installer HM70-100 PTO & Magneto w/dia. of 1.1870”-1.1875” 670336 - Seal Installer - Adpator HM70-100 w/ 1-1/8” crankshaft 670337 - Seal Installer for Ball Bearing PTO OHH engines, use w/ tool 670265

No. 670169 - Knock-off tool (right hand) (1/2"). No. 670314 - Knock-off tool (right hand) (5/8"). No. 670329 - Knock-off tool (right hand) (3/4").

OIL SEAL REMOVER

Consult the specification chart or measure the shaft diameter to determine the correct tool. NOTE: Due to variations in oil seal dimensions, these removers may not pull all oil seals. USE WITH: No. 670287. 7/8" Crankshaft bearing diameters No. 670288. 3/4" Crankshaft bearing diameters No. 670289. 13/16" Crankshaft bearing diameters No. 670290. 1" Crankshaft bearing diameters No. 670312. 1-3/8" Crankshaft bearing diameters No. 670331. 1-1/2" Crankshaft bearing diameters

VIBRATION TACHOMETER

No. 670156 Vibration tachometer.

TAPER GAP GAUGE

Use tool 670266

No. 670256 Taper Gap Gauge 103

VALVE LAPPING TOOL

1/32" (.794 mm) OVERSIZE VALVE GUIDE REAMER

No. 670154 Valve lapping tool. REBUSHING DRIVERS No. 670283. Used on small frame 4 cycle engines on Intake and Exhaust valve guides. Oversize diameter .2807 .2817 No. 670284. Used on medium and large frame 4 cycle engines on Intake and Exhaust. Oversize diameter .3432 .3442 Tool Number A. 670158 B. 670159 A. 670162 B. 670163 A. NONE B. 670311 670317

Description Use with: Bearing Driver 7/8'’ (22.225 mm) Main Bearings where bushings are available. Bushing Driver

OVRM and OHV11-17 ADJUSTMENT TOOL

Bearing Driver 1'’ (25.4 mm) Main Bearings where bushings are available Bushing Driver Bushing Driver 1-3/8'’ (41.275 mm) HM70 100, TVM170 220 and OVM120. Bushing Driver 1-3/16'’ (20.6375 mm) HM70, HM80 and HM100 Cylinder cover No. 670326

FLYWHEEL PULLER

No. 670298 Alignment Tool. No. 670306

104

DECIMAL/FRACTION CONVERSIONS .016 .031 .047 .063 .078 .094 .109 .125 .141 .156 .172 .188 .203 .219 .234 .25 .266 .281 .297 .312 .328 .344 .359 .375 .391 .406 .422 .438 .453 .469 .484 .50

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

1/64 1/32 3/64 1/16 5/64 3/32 7/64 1/8 9/64 5/32 11/64 3/16 13/64 7/32 15/64 1/4 17/64 9/32 19/64 5/16 21/64 11/32 23/64 3/8 25/64 13/32 27/64 7/16 29/64 15/32 31/64 1/2

.516 .531 .547 .563 .578 .594 .609 .625 .641 .656 .672 .688 .703 .719 .734 .75 .766 .781 .797 .813 .828 .844 .859 .875 .891 .906 .922 .938 .953 .969 .984

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

33/64 17/32 35/64 9/16 37/64 19/32 39/64 5/8 41/64 21/32 43/64 11/16 45/64 23/32 47/64 3/4 49/64 25/32 51/64 13/16 53/64 27/32 55/64 7/8 57/64 29/32 59/64 15/16 61/64 31/32 63/64

105

SEARS CRAFTSMAN CROSS REFERENCE CHARTS Craftsman Tecumseh

Craftsman Tecumseh

Craftsman Tecumseh

Craftsman Tecumseh

143.001000

TVM220-157285G

143.006512

LEV120-361037C

143.016700

LEV120-361515A

143.255012

LAV50-62027

143.001001

HM100-159411R

143.006700

LEV120-361501A

143.016702

LEV120-361517A

143.255022

LAV50-62029

143.001002

TVM220-157286G

143.006702

LEV120-361502A

143.016704

LEV120-361518A

143.255042

LAV50-62037

143.001101

HMSK110-159960A

143.006712

LEV120-361503A

143.016706

LEV120-361520A

143.255052

LAV50-62039A

143.001103

HMSK110-159961A

143.006714

LEV120-361509A

143.016708

LEV120-361521A

143.255062

LAV50-62043

143.001105

HMSK110-159963A

143.006716

LEV120-361510A

143.016710

LEV120-361522A

143.255072

LAV50-62043A

143.003001

H30-35517Y

143.008001

HM80-155658T

143.016712

LEV120-361523A

143.255082

LAV50-62015A

143.003500

LEV100-335023D

143.008003

HM80-155680T

143.016714

LEV120-361524A

143.255092

LAV50-62037A

143.003501

H35-45767Z

143.008501

HM85-155851B

143.016718

LEV120-361526A

143.255102

LAV50-62029A

143.003502

LEV100-335010D

143.009001

HMSK90-156530D

143.016720

LEV120-361527A

143.255112

LAV50-62039A

143.003504

LEV115-350144E

143.009003

HMSK90-156531D

143.016722

LEV120-361528A

143.257012

LAV40-50358D

143.003504

LEV115-350144E

143.009005

HM90-156017E

143.016724

LEV120-361529A

143.257022

LAV40-50358C

143.003506

TVS90-43775R

143.009007

HM90-156018E

143.016726

LEV120-361530A

143.257032

LAV40-50366D

143.003508

LEV100-335011D

143.009009

HM90-156019E

143.016728

LEV120-361531A

143.257042

LAV40-50201D

143.003800

VSK100-338501A

143.011000

TVM220-157220H

143.016730

LEV120-361532A

143.257052

LAV40-50369D

143.003802

LEV100-338012D

143.011002

TVM220-157286H

143.016732

LEV120-361533A

143.257062

LAV40-50369E

143.003804

TVS90-46129F

143.011004

TVM220-157285H

143.016734

LEV120-361534A

143.257072

LAV40-50366E

143.004000

LEV100-340048D

143.011101

HMSK110-159964A

143.016736

LEV120-361535A

143.265012

LAV50-62015A

143.004001

H40-55704A

143.011103

HMSK110-159965A

143.016738

LEV120-361536A

143.265032

LAV50-62047A

143.004002

LEV100-340037D

143.013500

LEV100-335011E

143.018001

HM80-155680U

143.265042

LAV50-62030A

143.004004

LEV100-340024D

143.013501

H35-45768Z

143.018501

HM85-155853C

143.265052

LAV50-62049A

143.004006

TVS90-48048D

143.013502

LEV100-335010E

143.019001

HMSK90-156534D

143.265062

LAV50-62039B

143.004008

LEV115-350159E

143.013503

H35-45777Z

143.019003

HMSK90-156536D

143.265072

LAV50-62047B

143.004010

LEV100-340031D

143.013802

LEV100-338022E

143.019005

HMSK90-156537D

143.265082

LAV50-62015B

143.004012

LEV100-340033D

143.014000

LEV100-340031E

143.019007

HM90-156021F

143.265092

LAV50-62029B

143.004014

LEV100-340015D

143.014001

H40-55705A

143.019009

HM90-156018F

143.265112

LAV50-62037B

143.004016

LEV100-340016D

143.014002

LEV100-340032E

143.019011

HM90-156019F

143.265122

LAV50-62043B

143.004018

LEV115-350168E

143.014004

LEV100-340033E

143.021101

HMSK110-159964B

143.265132

LAV50-62050B

143.004500

LEV120-361069C

143.014006

LEV100-340015E

143.021103

HMSK110-159965B

143.265142

LAV50-62051B

143.004502

LEV100-345014D

143.014008

LEV100-340016E

143.025001

HSSK50-67410S

143.265152

LAV50-62052B

143.004504

LEV100-345006D

143.014010

LEV100-340017E

143.025003

HSSK50-67411S

143.265162

LAV50-62053B

143.004506

TVS115-57065G

143.014012

LEV100-340021E

143.025005

HSSK50-67412S

143.265172

LAV50-62024B

143.005001

HSSK50-67399S

143.014014

LEV100-340024E

143.029001

HMSK90-156534E

143.265192

LAV50-62049B

143.005003

HSSK50-67400S

143.014016

LEV100-340052E

143.029003

HMSK90-156536E

143.267012

LAV40-50368E

143.005004

LEV115-350128E

143.014500

LEV120-361082C

143.029005

HMSK90-156537E

143.267022

LAV40-50368F

143.005006

LEV115-350090E

143.014502

LEV100-345006E

143.207012

LAV40-50254B

143.267042

LAV40-50369F

143.005008

LEV115-350060E

143.014504

LEV100-345021E

143.207022

LAV40-50205B

143.274092

LAV35-40938L

143.005504

LEV115-355021E

143.014506

LEV120-361105C

143.207032

LAV40-50207B

143.274102

LAV35-40939L

143.005506

TVS115-62124D

143.015000

LEV115-350121E

143.207042

LAV40-50254B

143.274112

LAV35-40940L

143.005508

LEV120-361504A

143.015001

HSSK50-67405S

143.207052

LAV40-50201B

143.274122

LAV35-40941L

143.005510

LEV115-355022E

143.015002

LEV115-350189E

143.207072

LAV40-50270B

143.274132

LAV35-40942L

143.005512

LEV120-361075C

143.015003

HSSK50-67406S

143.217042

LAV40-50254C

143.274162

LAV35-40899L

143.006000

LEV115-360021D

143.015004

LEV115-350192E

143.217062

LAV40-50207C

143.274172

LAV35-40943L

143.006002

TVS120-66021C

143.015005

HSSK50-67407S

143.217072

LAV40-50201C

143.274182

LAV35-40944L

143.006004

LEV115-360025D

143.015007

HSSK50-67408S

143.217102

LAV40-50217C

143.274252

LAV35-40751L

143.006006

LEV115-360024D

143.015500

LEV115-355026E

143.235032

LAV50-62002

143.274272

LAV35-40948L

143.006200

LEV115-360026D

143.015502

LEV120-361096C

143.235072

LAV50-62010

143.274282

LAV35-40949L

143.006202

TVS120-66020C

143.015504

LEV120-361097C

143.237042

LAV40-50336C

143.274292

LAV35-40950L

143.006204

LEV120-361505A

143.016000

LEV115-360033D

143.245012

LAV50-62012

143.274302

LAV35-40951L

143.006206

LEV115-360030D

143.016002

LEV115-360034D

143.245012

LAV50-62012

143.274312

LAV35-40952L

143.006502

LEV120-361044C

143.016004

LEV115-360035D

143.245092

LAV50-62015

143.274322

LAV35-40953L

143.006504

LEV120-361013C

143.016200

LEV115-360031D

143.245142

LAV50-62018

143.274332

LAV35-40954L

143.006506

LEV120-361054C

143.016202

LEV120-361519A

143.245152

LAV50-62019

143.274352

LAV35-40955L

143.006508

LEV120-361047C

143.016502

LEV120-361093C

143.245172

LAV50-62023

143.274372

LAV35-40956L

143.006510

LEV120-361045C

143.016504

LEV120-361537A

143.245182

LAV50-62024

143.274472

LAV35-40957L

E

SEARS CRAFTSMAN CROSS REFERENCE CHARTS Craftsman Tecumseh

Craftsman Tecumseh

Craftsman Tecumseh

Craftsman Tecumseh

143.274492

LAV35-40858L

143.284712

LAV35-40926M

143.314482

TVS90-43150B

143.331012

TVS75-33025D

143.274552

LAV35-40961L

143.284722

LAV35-40917M

143.314542

TVS90-43066B

143.331022

TVS75-33012D

143.274592

LAV35-40962L

143.284732

LAV35-40859M

143.314552

TVS90-43088B

143.334022

TVS90-43173D

143.274642

LAV35-40626L

143.284762

LAV35-40463M

143.314562

TVS90-43116B

143.334032

TVS90-43174D

143.274662

LAV35-40967L

143.285012

LAV50-62050C

143.314702

LAV35-40906N

143.334052

TVXL105-54012B

143.274682

LAV35-40882L

143.285022

LAV50-62024C

143.314722

TVS90-43139B

143.334062

TVS90-43175D

143.274702

LAV35-40926L

143.285032

LAV50-62066C

143.314732

TVS90-43140B

143.334072

TVS90-43176D

143.274772

LAV35-40924L

143.285042

LAV50-62049C

143.314742

TVS90-43141B

143.334112

TVS90-43177D

143.274792

LAV35-40774L

143.285052

LAV50-62067C

143.314752

TVS90-43142B

143.334122

TVS90-43178D

143.275012

LAV50-62059B

143.285062

LAV50-62065C

143.314762

TVS90-43143B

143.334142

TVS90-43068D

143.275012

LAV50-62059B

143.285072

LAV50-62037C

143.314772

TVS90-43144B

143.334152

TVS90-43019D

143.275022

LAV50-62060B

143.285082

LAV50-62063C

143.315022

LAV50-62071D

143.334162

TVS90-43145D

143.275042

LAV50-62018B

143.285092

LAV50-62068C

143.315032

TVS105-53018B

143.334192

LAV35-40917P

143.275052

LAV50-62063B

143.285102

LAV50-62043C

143.315042

TVS105-53025B

143.334202

TVS90-43116D

143.275062

LAV50-62065B

143.287012

LAV40-50389E

143.315062

LAV50-62065D

143.334262

TVS90-43139D

143.275072

LAV50-62019B

143.287022

LAV40-50391D

143.315072

TVS105-53006B

143.334272

TVS90-43140D

143.275082

LAV50-62066B

143.287032

LAV40-50392E

143.315092

LAV50-62037D

143.334282

TVS90-43141D

143.277012

LAV40-50387D

143.294552

TVS105-53012A

143.315102

LAV50-62053D

143.334292

TVS90-43142D

143.277022

LAV40-50382D

143.294562

TVS105-53013A

143.315112

LAV50-62050D

143.334302

TVS90-43143D

143.284012

LAV35-40969M

143.294622

TVS105-53017A

143.315122

LAV50-62067D

143.334312

TVS90-43144D

143.284022

LAV35-40970M

143.294632

TVS105-53018A

143.321012

TVS75-33010C

143.334332

TVS90-43201D

143.284032

LAV35-40971M

143.294642

TVS105-53016A

143.321022

TVS75-33012C

143.334352

TVS90-43121D

143.284052

LAV35-40972M

143.294702

TVS105-53025A

143.324052

TVS90-43020C

143.334362

TVS90-43215D

143.284062

LAV35-40973M

143.295012

LAV50-62071C

143.324112

TVS90-43116C

143.334372

TVS90-43220D

143.284082

LAV35-40974M

143.295022

LAV50-62072C

143.324142

TVS90-43139C

143.334382

TVS90-43226D

143.284092

LAV35-40975M

143.295032

LAV50-62053C

143.324152

TVS90-43121C

143.335032

LAV50-62037E

143.284112

LAV35-40977M

143.297012

TVS105-53006A

143.324162

TVS90-43025C

143.335042

LAV50-62067E

143.284142

LAV35-40980M

143.304362

LAV35-40906M

143.324172

TVS90-43142C

143.335052

TVS120-63209A

143.284152

LAV35-40981M

143.305042

LAV50-62073C

143.324182

TVXL105-54009A

143.335062

LAV50-62065E

143.284162

LAV35-40982M

143.305062

LAV50-62074C

143.324192

TVS90-43144C

143.335072

TVS120-63210A

143.284182

LAV35-40986M

143.313012

TVS75-33010B

143.326012

TVM195-150016H

143.336012

TVM140-70371K

143.284222

LAV30-30538M

143.313022

TVS75-33012B

143.326022

TVM195-150062H

143.336022

TVM220-157058D

143.284242

LAV35-40990M

143.314032

TVS90-43020B

143.326032

TVM195-150063H

143.336032

TVM220-157062D

143.284252

LAV35-40991M

143.314042

TVS90-43022B

143.326042

TVM195-150114H

143.336042

TVM220-157069D

143.284282

LAV35-40992M

143.314052

TVS90-43023B

143.326052

TVM195-150122H

143.341012

TVS75-33039D

143.284292

LAV35-40993M

143.314062

TVS90-43025B

143.326062

TVM195-150017H

143.344022

TVS90-43213D

143.284302

LAV35-40994M

143.314072

TVS90-43032B

143.326072

TVM195-150065H

143.344032

TVS90-43214D

143.284312

LAV35-40882M

143.314082

TVS90-43033B

143.326082

TVM195-150071H

143.344042

TVS90-43221D

143.284322

LAV35-40858M

143.314092

TVS90-43094B

143.326092

TVM195-150039H

143.344072

TVS90-43219D

143.284392

LAV35-40751M

143.314102

TVS90-43095B

143.326102

TVM195-150080H

143.344102

TVS90-43222D

143.284402

LAV35-40995M

143.314112

TVS90-43096B

143.326112

TVM195-150064H

143.344112

TVXL105-54017B

143.284412

LAV35-40996M

143.314182

TVS90-43121B

143.326122

TVM220-157028D

143.344142

TVS90-43230D

143.284422

LAV35-40962M

143.314262

TVS90-43059B

143.326132

TVM220-157035D

143.344162

TVS90-43250D

143.284442

LAV30-30539M

143.314272

TVS90-43061B

143.326142

TVM220-157014D

143.344182

TVS90-43252D

143.284482

LAV35-40961M

143.314282

TVS90-43107B

143.326152

TVM220-157026D

143.344192

TVS90-43253D

143.284512

LAV35-40997M

143.314292

TVS90-43019B

143.326162

TVM220-157047D

143.344202

TVS90-43254D

143.284522

LAV35-40998M

143.314302

TVS90-43134B

143.326172

TVM220-157027D

143.344212

TVS90-43255D

143.284542

LAV35-40999M

143.314322

TVS90-43040B

143.326182

TVM220-157025D

143.344222

TVS90-43256D

143.284552

LAV35-41000M

143.314332

TVS90-43112B

143.326282

TVM140-70281K

143.344402

TVXL105-54020B

143.284562

LAV35-41001M

143.314342

TVS90-43111B

143.326292

TVM140-70259K

143.344412

TVXL105-54021B

143.284572

LAV35-41002M

143.314362

TVS90-43145B

143.326302

TVM140-70304K

143.344422

TVS90-43268D

143.284592

LAV35-41003M

143.314382

TVS90-43044B

143.326322

TVM170-127008C

143.344432

TVS90-43269D

143.284632

LAV35-41006M

143.314402

TVS90-43068B

143.326332

TVM195-150116H

143.344442

TVS105-53059D

143.284652

LAV35-40923M

143.314412

TVS90-43108B

143.326342

TVM195-150134H

143.344462

TVS105-53067D

143.284662

LAV35-40938M

143.314432

LAV35-40917N

143.326372

TVM170-127009C

143.345032

TVS120-63211A

EE

SEARS CRAFTSMAN CROSS REFERENCE CHARTS Craftsman Tecumseh

Craftsman Tecumseh

Craftsman Tecumseh

Craftsman Tecumseh

143.345042

LAV50-62082E

143.356082

TVM220-157083F

143.374072

TVS90-43358E

143.384392

TVS90-43403F

143.346012

TVM220-157058E

143.356092

TVM220-157084F

143.374082

TVS90-43359E

143.384402

TVS105-53107F

143.346022

TVM220-157062E

143.356102

TVM170-127013E

143.374212

TVS90-43360E

143.384412

TVS105-53602F

143.346032

TVM170-127008D

143.356122

TVM195-150154K

143.374222

TVS90-43361E

143.384422

TVS105-53607F

143.346042

TVM195-150116J

143.356132

TVM195-150155K

143.374232

TVS90-43362E

143.384432

TVS100-44604B

143.346052

TVM195-150134J

143.356142

TVM195-150156K

143.374292

TVS105-53601E

143.384442

TVS90-43405F

143.346062

TVM220-157069E

143.356152

TVM195-150157K

143.374302

TVS90-43371E

143.384452

TVS90-43375F

143.346072

TVM220-157035E

143.356162

TVM220-157085F

143.374312

TVS105-53101E

143.384462

ECV100-145273G

143.346082

TVM170-127009D

143.356172

TVM220-157086F

143.374322

TVS90-43342E

143.384472

ECV100-145291G

143.346092

TVM195-150016J

143.356182

TVM220-157087F

143.374332

TVS90-43375E

143.384482

ECV100-145292G

143.346102

TVM195-150114J

143.356192

TVM220-157088F

143.374362

TVS90-43307E

143.384492

ECV100-145266G

143.346112

TVM195-150122J

143.356202

TVM220-157089F

143.374372

TVS105-53602E

143.384502

ECV100-145290G

143.346122

TVM195-150039J

143.356212

TVM220-157090F

143.374382

TVS90-43215E

143.384512

ECV100-145288G

143.346132

TVM195-150080J

143.356222

TVM220-157091F

143.374422

TVS105-53102E

143.384522

ECV100-145297G

143.346142

TVM220-157028E

143.356232

TVM220-157093F

143.374432

TVS90-43389E

143.384532

ECV100-145289G

143.346152

TVM220-157014E

143.356252

TVM220-157097F

143.375042

LAV50-62037F

143.384542

ECV100-145310G

143.346162

TVM220-157026E

143.356362

TVM125-60251L

143.376022

TVM220-157106H

143.384552

TVS90-43389F

143.346172

TVM220-157047E

143.361012

TVS75-33054D

143.376042

TVM195-150164M

143.384562

ECV100-145320G

143.346182

TVM220-157027E

143.364012

TVS90-43333D

143.376052

TVM220-157115H

143.384572

TVS90-43415F

143.346192

TVM220-157025E

143.364082

TVS90-43334D

143.376062

TVM195-150151M

143.385042

LAV50-62037G

143.346202

TVM125-60249K

143.364102

TVS90-43335D

143.376092

TVM220-157083H

143.385052

LAV50-62082G

143.351012

TVS75-33046D

143.364112

TVS90-43336D

143.381012

TVS75-33061F

143.386022

TVM220-157120J

143.351022

TVS75-33052D

143.364122

TVS90-43337D

143.381022

TVS75-33059F

143.386042

TVM220-157122J

143.354012

TVS90-43290D

143.364132

TVS90-43338D

143.384012

TVS90-43379F

143.386052

TVM195-150152N

143.354062

TVS90-43291D

143.364142

TVS90-43339D

143.384022

TVS90-43380F

143.386062

TVM220-157083J

143.354092

TVS90-43292D

143.364202

TVS90-43341D

143.384032

TVS90-43381F

143.386072

TVM220-157084J

143.354102

TVS90-43293D

143.364222

TVS90-43342D

143.384042

TVS90-43382F

143.386082

TVM220-157097J

143.354122

TVS90-43294D

143.364262

TVS105-53087D

143.384052

TVS90-43383F

143.386122

TVM195-150151N

143.354132

TVXL105-54024B

143.364352

TVS90-43346E

143.384062

TVS90-43384F

143.386132

TVM195-150164N

143.354142

TVS90-43295D

143.364362

TVS90-43347E

143.384072

TVS90-43385F

143.386142

TVM220-157115J

143.354162

TVS90-43289D

143.364372

TVS90-43348E

143.384082

TVS90-43386F

143.386172

TVM220-157126H

143.354172

TVS90-43288D

143.364392

TVS90-43351D

143.384092

ECV100-145313G

143.386182

TVM220-157128J

143.354182

TVS90-43296D

143.364402

TVS105-53090D

143.384102

ECV100-145314G

143.391012

TVS75-33066F

143.354192

TVS90-43297D

143.366022

TVM195-150134L

143.384112

ECV100-145315G

143.394012

ECV100-145323G

143.354202

TVS90-43298D

143.366032

TVM220-157069G

143.384122

ECV100-145316G

143.394022

TVS90-43420F

143.354212

TVS90-43299D

143.366042

TVM195-150151L

143.384172

ECV100-145317G

143.394032

TVS90-43422F

143.354232

TVS90-43300D

143.366052

TVM220-157093G

143.384202

ECV100-145318G

143.394042

TVS90-43423F

143.354282

LAV35-40917R

143.366062

TVM220-157081G

143.384212

ECV100-145319G

143.394052

TVS90-43424F

143.354292

TVS90-43307D

143.366082

TVM125-60252L

143.384222

ECV100-145258G

143.394062

TVS90-43425F

143.354312

TVS90-43312D

143.366102

TVM195-150152L

143.384232

ECV100-145295G

143.394072

TVS90-43426F

143.354322

TVS90-43315D

143.366112

TVM220-157083G

143.384242

ECV100-145296G

143.394082

ECV100-145324G

143.354332

TVS90-43316D

143.366122

TVM220-157084G

143.384252

ECV100-145286G

143.394122

TVS90-43438F

143.354342

TVS90-43321D

143.366132

TVM220-157097G

143.384262

ECV100-145287G

143.394132

TVS90-43421F

143.354352

TVS90-43322D

143.366152

TVM195-150163L

143.384272

TVS90-43342F

143.394142

TVS90-43428F

143.354482

TVS105-53077D

143.366172

TVM220-157108G

143.384282

TVS90-43347F

143.394152

TVS90-43443F

143.354492

TVS105-53083D

143.366182

TVM125-60254L

143.384292

TVS90-43346F

143.394162

ECV100-145333G

143.354502

TVS105-53084D

143.366192

TVM220-157106G

143.384302

TVS90-43215F

143.394172

ECV100-145327G

143.355032

LAV50-62050F

143.366222

TVM220-157110G

143.384312

TVS90-43396F

143.394222

ECV100-145326G

143.356012

TVM220-157081F

143.371012

TVS75-33056E

143.384322

ECV100-145321G

143.394232

ECV100-145325G

143.356022

TVM125-60249L

143.371022

TVS75-33057E

143.384332

ECV100-145322G

143.394242

TVS90-43451F

143.356032

TVM195-150134K

143.371032

TVS75-33059E

143.384342

TVS90-43348F

143.394252

ECV100-145330G

143.356042

TVM220-157069F

143.374012

TVS90-43352E

143.384352

ECV100-145285G

143.394262

ECV100-145332G

143.356052

TVM195-150151K

143.374022

TVS90-43353E

143.384362

ECV100-145294G

143.394272

ECV100-145331G

143.356062

TVM125-60251L

143.374032

TVS90-43354E

143.384372

ECV100-145293G

143.394282

ECV100-145329G

143.356072

TVM195-150152K

143.374052

TVS90-43356E

143.384382

TVS90-43402F

143.394302

TVS90-43454F

EEE

SEARS CRAFTSMAN CROSS REFERENCE CHARTS Craftsman Tecumseh

Craftsman Tecumseh

Craftsman Tecumseh

Craftsman Tecumseh

143.394312

TVS90-43455F

143.404382

TVS105-53906G

143.414342

TVS105-53903H

143.424322

TVS105-56006

143.394322

TVS90-43456F

143.404392

TVS105-53907G

143.414362

TVS105-53911H

143.424332

TVS120-63134H

143.394332

TVS90-43457F

143.404402

TVS120-63902F

143.414372

TVS105-53169H

143.424342

TVS120-63135H

143.394342

ECV100-145334G

143.404412

TVS105-53147G

143.414382

TVS105-53151H

143.424352

TVS105-53180J

143.394352

ECV100-145335G

143.404422

TVS105-53148G

143.414402

TVS105-53902H

143.424362

TVS90-43555H

143.394362

ECV100-145336G

143.404432

TVS105-53149G

143.414412

TVS105-53168H

143.424372

TVS90-43556H

143.394372

ECV100-145337G

143.404442

TVS105-53150G

143.414422

TVS120-63115G

143.424382

TVS105-56007

143.394382

ECV100-145338G

143.404452

TVS105-53151G

143.414482

TVS105-53139H

143.424392

TVS105-56907

143.394392

ECV100-145339G

143.404462

TVS105-53152G

143.414492

TVS120-63120G

143.424402

TVS120-63902H

143.394402

ECV100-145340G

143.404472

TVS120-63120F

143.414502

TVS90-43534G

143.424412

TVS90-43558H

143.394412

ECV100-145341G

143.404482

TVS120-63903F

143.414522

TVS90-43901G

143.424462

TVS100-44038D

143.394422

ECV100-145342G

143.404502

TVS90-43504F

143.414542

TVS105-53907H

143.424472

TVS90-43515H

143.394442

ECV100-145344G

143.404532

TVS90-43497F

143.414572

TVS120-63902G

143.424482

TVS120-63137H

143.394452

ECV100-145345G

143.406022

TVXL220-157205A

143.414582

TVS105-53910H

143.424492

TVS105-53920J

143.394462

ECV100-145346G

143.406032

TVXL220-157215A

143.414592

TVS105-53912H

143.424502

TVS120-63915H

143.394472

ECV100-145347G

143.406042

TVXL220-157220A

143.414602

TVS105-53913H

143.424512

TVS90-43298H

143.394482

ECV100-145348G

143.406082

TVM125-60261L

143.414612

TVS90-43537G

143.424532

TVS100-44043D

143.394492

TVS90-43458F

143.406092

TVXL195-150233

143.414622

TVS120-63127G

143.424542

TVS100-44045D

143.394502

LAV35-40917S

143.406102

TVXL220-157230A

143.414632

TVS105-53914H

143.424552

TVS100-44046D

143.394512

ECV100-145349G

143.406122

TVXL220-157206A

143.414642

TVS120-63907G

143.424562

TVS90-43389H

143.394522

TVS100-44605B

143.406172

TVXL195-150238

143.414652

TVS105-53175H

143.424572

TVS90-43299H

143.395012

ECV120-152044D

143.414012

TVS90-43512G

143.414662

TVS105-53176H

143.424582

TVS120-63916H

143.395022

ECV120-152045D

143.414022

TVS105-53162H

143.414672

TVS105-53177H

143.426012

TVM125-60261M

143.396022

TVXL220-157213

143.414032

TVS90-43513G

143.414682

ECV100-145349H

143.426032

TVXL195-150238A

143.396042

TVXL220-157206

143.414042

TVS90-43514G

143.416032

TVXL220-157240A

143.426042

TVXL220-157205B

143.396052

TVXL220-157205

143.414052

TVS90-43515G

143.416052

TVM125-60254M

143.426052

TVXL220-157206B

143.396082

TVXL220-157215

143.414062

TVS105-53163H

143.416072

TVXL220-157241A

143.426062

TVXL220-157220B

143.396102

TVM125-60258L

143.414072<