Detailed instructions for use are in the User's Guide.
[. . . ] TECUMSEH
TECHNICIAN'S HANDBOOK
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.
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3 TO 11 HP 4-CYCLE L-HEAD ENGINES
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CONTENTS
CHAPTER 1 GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ENGINE IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 INTERPRETATION OF MODEL NUMBER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SHORT BLOCKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] 8
7
9
10 44
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BASIC CHECKS
Before going into extensive checks, be sure to perform the more basic checks first, such as: 1. Corroded or loose terminals and connections, or wrong connections. A wire "grounding out" in the system. 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.
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TROUBLESHOOTING ELECTRICAL STARTER CIRCUIT FLOW CHART
Starter will not turn
Intermittent starter operation
Starter turns at low rpms or stalls under load
NO
Is there power at the power source?
YES
Repair or replace power source
NO
Is power supplied to the starter terminal?
YES
Check wiring, connections, safety switches, starter switch
NO
Isolate engine from the equipment, does engine turn over?
YES
Check starter for binding brushes, worn brushes, dirty or oily commutator
NO
Remove spark plug, does engine turn over freely?
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. Does the engine turn over without binding now?
NO Repair or replace electric starter Internal engine failure, repair or replace engine
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TROUBLESHOOTING ELECTRICAL CHARGING CIRCUIT FLOW CHART
Identify the charging system used by model and specification number or visually check the electrical plug
Consult the Technician's Handbook or Electrical Troubleshooting booklet for test procedure for the charging system used
Test for either AC or DC voltage as directed at the proper engine RPM
NO
Is the voltage greater than or equal to the minimum value?
YES
NO
Is AC voltage before diode or YES rectifier greater than the minimum value?
Check wiring, switches, or ammeter for breaks, shorts
Alternator coil failure, replace coil assy.
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
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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. Check the electric starter terminal for the required voltage (12v D. C. CAUTION: FOLLOW ALL SAFETY PRECAUTIONS WHEN TESTING FOR A. C. Check wiring, connections, fuses, ignition or starter switch, safety switches, or solenoid for continuity using a ohmmeter or a continuity light. 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. 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. 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. 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. [. . . ] 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 Includes 670268 & 670269 (I. D. . 875" and . 935") H30-35, LAV30-35, TNT100, TVS75-90, ECV90-100 670294 Includes 670273 & 670274 (I. D. . 680" and 1. 005") AH520 & AH600 with one piece oil seal 670330 OHV13. 5-17 w/ 1-1/2" extended camshaft 670335 HM70-100 PTO & Magneto w/dia. of 1. 1870"-1. 1875" 670336 HM70-100 w/ 1-1/8" crankshaft 670337 OHH engines, use w/ tool 670265
Use tool 670266
No. [. . . ]