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Tecumseh HH100 Handbook Download Page 67

65

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

8-12-19-20-21-23

shut off

Performance unsatisfactory after being serviced ..

1thru 14 and 17 thru 23

1. Open fuel shut-off valve at fuel tank, fill tank

with fuel.

2. Examine and clean fuel line and filter (where

applicable).

3. Check ignition, spark plug and compression.

4. Clean air cleaner, service as required.

5. Dirt or restriction in fuel system, clean tank and

fuel strainers, check for kinks or sharp bends.

6. Check for stale fuel or water in fuel, fill with fresh

fuel.

7. Examine fuel line and pick-up for sealing at fittings.

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.

11. Examine idle and main mixture adjustment screws

and “O” rings for cracks or damage.

12. Adjust main mixture adjustment screw. Check

to see that it is the correct screw.

13. Examine main nozzle and replace with service

nozzle.

14. Adjust idle mixture adjustment screw. Check to

see that it is the correct screw.

15. Adjust idle speed screw.

16. Check position of choke and throttle plates.

17. Adjust control cable or linkage to assure full choke

and carburetor control.

18. Clean carburetor after removing all non-metallic

parts that are serviceable. Trace all passages.

19. Check inlet needle and seat condition and proper

installation.

20. Check sealing of welch plugs, cups, plugs and

gaskets.

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.

24. Check float shaft for wear and float for leaks or

dents.

25. Check seal for fuel drain or bowl gasket.

26. Is carburetor operating at excessive angle, 31°

or more ?

Summary of Contents for HH100

Page 1: ... 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 ...

Page 2: ...ION 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 CONT...

Page 3: ...n 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 n...

Page 4: ...umseh 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 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 ...

Page 5: ...n 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 Bo...

Page 6: ...E TYPE AIR CLEANER Some Tecumseh Large Frame engines may use a polyurethane air filter in conjunction with a paper filter 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 a...

Page 7: ...s used on the Overhead Valve engine 12 14 16 18 horsepower 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 ...

Page 8: ...ter and pull out the throttle shaft lever assembly 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 CHOKE Examine the choke lever shaft and s...

Page 9: ...full travel of the float 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 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 ...

Page 10: ...ositioned 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 When all accessories and shafts have been removed soak the carburetor in carburetor cleaner for a maximum of 30 minutes ...

Page 11: ...oss 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 blade...

Page 12: ...ottle return or realigning the throttle plate 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 Examine the inlet needle A is a needle ...

Page 13: ...oat setting is 140 3 556 mm For engines with the new carburetor without a fuel pump the float setting is 075 1 905 mm 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 Float settings are measured opposite th...

Page 14: ...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 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 W...

Page 15: ... slow position adjust idle speed adjustment screw to obtain correct idle speed If necessary readjust idle adjustment screw until engine idles smoothly 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 shoul...

Page 16: ...sembly 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 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 Position carburetor in an upright position If float is low...

Page 17: ...D 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 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 in...

Page 18: ...losed end for lubrication CAUTION On reassembly make sure hole is open Other models have a groove on the inside that serves the same purpose 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 go...

Page 19: ...unch 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 Move r...

Page 20: ...ease R P M and out counterclockwise to increase R P M CAUTION DO NOT EXCEED RECOMMENDED R P M 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 spee...

Page 21: ... 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 If the flow is erratic or intermittent the pump needs repair or replacement CARBURETOR FITTING VALVE OPEN DIAPHRAGM VALVE CLOSED PULSE LINE TO CRANKCASE FUEL SUPPLY AIR BLEED...

Page 22: ...t 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 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 ret...

Page 23: ...ARTER 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 ...

Page 24: ...ove 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 c Remove dust cover retaining ring spring retainer anti drift spring gear and engaging nut Remove drive end cap from armature 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...

Page 25: ...k 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 eac...

Page 26: ...r 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 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...

Page 27: ...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 Remove wire from starter Use a jumper battery engine 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 c...

Page 28: ...tact with grease or oil Loose or faulty electrical Correct connections 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 Clean drive assembly and armature shaft and disengagement ...

Page 29: ...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 clockw...

Page 30: ...ide 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 ROCKER ARM SHAFT The rocker arm shaft is not a replaceable part The r...

Page 31: ...s 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 VALVE SEAT CUTTING REQUIREMENTS Cut valve seats to 46 and valve to 45 See Specifications VALVE GUIDE DIMENSI...

Page 32: ...h to make contact with the head when pressing out the guides 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 b...

Page 33: ...EAD 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 HEAD ASSEMBLY TORQUE...

Page 34: ...t 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 VALVE IN HEAD ENGINES FOR 8 HP AND LARGER EXCEPT VALVE IN HEAD DRAIN HOLES MUST BE TOWARD ENGINE BASE BREATHER BODY AND VALVE BREATHER BODY AND VALV...

Page 35: ...e 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 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 ...

Page 36: ...ks 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 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 ...

Page 37: ...re 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 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 cr...

Page 38: ...aft 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 shoul...

Page 39: ... 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 VALVE TIMING Match chamfered gear tooth on crankshaft with mark and hobbing hole on camshaft gear VALVE TIMING FOR ENGINE WITH HELICAL CUT GEARS NOTE When matching up helical gears do so with a slight r...

Page 40: ...TRUCTIONS 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 botto...

Page 41: ...ice 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 Determine the gap between the cover and the machined surface on the cylinder which should be from 001 007 025 mm 1...

Page 42: ...shaft and test for freedom of movement There shall not be any crankshaft end play The only exception is the VH100 with oil pump 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 With either fingers or two screwdrivers press the bearing cup inward until tight NOTE When measu...

Page 43: ...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 addi...

Page 44: ...ive 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 OIL SEAL MUST BE SQUARE IN BORE DRIVE OIL SEAL FLUSH TO 025 635 mm BELOW SURFACE CYLINDE...

Page 45: ...he counterbalancing gears are placed top and bottom of crankshaft 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 flang...

Page 46: ...he 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 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 BEARING REPLACEMENT If rep...

Page 47: ...gap Follow through the checks and explanations below if everything checks ok then replace the ignition unit REMOVAL OF FLYWHEEL TRIGGER PINS 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 Use vise grip pliers to remove the pins If the pins are very tight hammer lightly on the pliers ...

Page 48: ...rt through the equipment frame FOR 10 AMP IGNITION SYSTEM 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...

Page 49: ... 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 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 pre...

Page 50: ...IS THRU MT G BOLTS MAGNETO GROUND A C A C A C A C LIGHT ETC SWITCH GROUND IS THRU MT G SCREWS SOLID STATE RECTIFIER REGULATOR BATTERY KEY SWITCH AMMETER BATTERY SOLENOID GROUND IS THRU THE MOUNTING BOLTS STARTING MOTOR A C YELLOW LEADS VIEW A A VIEW F F MAG GROUND GREEN LEAD 30 AMP FUSE LIGHT ETC GROUND IS THRU MT G SCREWS A C B SWITCH PRECAUTIONS CAUTION Electrical components of the 10 amp altern...

Page 51: ...ltmeter 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 1 Defective stator than 16 volts 2 Voltage reads over 16 volts 2 Defective regulator rectifier 3 3000 RPM Voltage reads l...

Page 52: ...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 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 ...

Page 53: ...lator to positive side of battery 1 2500 RPM 12 5 volts load 1 Defective stator current reads less than 13 amps 2 3000 RPM 12 5 volts load 2 Defective stator current reads less than 15 amps 3 3600 RPM 12 5 volts load 3 Defective stator current reads less than 17 amps GREEN YELLOW YELLOW YELLOW YELLOW GREEN GREEN RED RED FUSE SWITCH RECT REG R B M D C VOLTMETER BATTERY TEST SETUP ON NEW 20 AMP SYST...

Page 54: ...battery 3600 RPM 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 Overfilled battery may appear to fume due to expansion GREEN YELLOW YELLOW YELLOW YELLOW GREEN GREEN RED RED FUSE SWITCH RECT REG R B M D C VOLTMETER BATTERY TEST SETUP ON NEW 20 AMP SYSTEMS WITH RECTIFIER REGULATOR IN BLOWE...

Page 55: ...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 4 Check polarity to be sure batter...

Page 56: ...ll 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 SPECIFIC GRAVITY CHECK Use a hydromet...

Page 57: ...55 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 ...

Page 58: ...itch 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 STARTER SWITCH Remove wires from starter switch Place test leads on to switch terminals N...

Page 59: ...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 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 c...

Page 60: ... If either of the tests do not give the correct results replace the switch 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 rever...

Page 61: ...ng chart Panel wiring Correct problem Starter Cranks Engine But Engine Toggle switch If inoperative replace See Does Not Start Service Instructions on preceding pages Insure spade connectors are Correct See Service Instructions secured to appropriate switch on preceding pages See terminals Engine Fails to Start Ammeter Does Not Show A Charge Weak or bad battery Charge or replace If battery is full...

Page 62: ...ys Check battery connections for Correct problem corrosion and or breaks 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 Toggle Switch If inoperative replace See Engine Does Not Start Se...

Page 63: ...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 magne...

Page 64: ...l 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 f...

Page 65: ...leak out Valve guides worn Ream valve guide oversize and install 1 32 787 mm oversize valve Cylinder wall worn or glazed allowing oil to pass Deglaze cylinder as necessary rings into combustion chamber 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 h...

Page 66: ... 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 s...

Page 67: ...for stale fuel or water in fuel fill with fresh fuel 7 Examine fuel line and pick up for sealing at fittings 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 11 Examine idle and main mixture adjustment screws and O rings for cracks or damage 12...

Page 68: ...72 HH100 143 592012 HH120 143 592022 HH120 143 592032 HH120 143 592052 HH120 143 592062 HH120 143 592072 HH120 143 592082 HH120 143 598012 HH80 143 599012 HH100 143 599022 HH100 143 599042 HH100 143 599052 HH100 143 599062 HH100 143 602012 HH120 143 602022 HH120 143 602032 HH120 143 602052 HH120 143 602062 HH120 143 602072 HH120 143 602082 HH120 143 602092 HH120 143 602102 HH120 143 602112 HH120 1...

Page 69: ...052 1 321mm Valve Face Angle 45 45 45 45 45 45 Valve Face Width 089 2 261 089 2 261 089 2 261 099 2 515 099 2 515 099 2 515 Valve Lip Width 06 1 524 06 1 524 06 1 524 Valve Spring Free Length 1 885 47 879 1 885 47 879 1 885 47 879 Valve Guides STD Diameter 312 7 925 312 7 925 312 7 925 313 7 950 313 7 950 313 7 950 Valve Guides Over Size Dimensions 343 8 712 343 8 712 343 8 712 344 8 738 344 8 738...

Page 70: ...Clearance 002 051 002 051 003 076 005 127 005 127 006 127 Camshaft Bearing Diameter 6235 15 837 6235 15 837 6235 15 837 6240 15 850 6240 15 850 6240 15 850 Cam Lobe Diameter Nose to Heel 1 3045 33 134 1 3045 33 134 1 3045 33 134 1 3085 33 326 1 3085 33 236 1 3085 33 236 Magneto Air Gap 006 152 006 152 006 152 010 254 010 254 010 254 Model VH80 VH100 U S Metric U S Metric Displacement 23 7 388 4 cc...

Page 71: ...30 150 Crankshaft End Play None None Piston Diameter 3 308 84 023 3 308 84 023 3 310 84 074 3 310 84 074 Piston Pin Diameter 6873 17 457 6873 17 457 6875 17 463 6875 17 463 Width Comp Ring Groove 0950 2 41 0950 2 41 0960 2 438 0960 2 438 Width Oil Ring Groove 1800 4 572 1800 4 572 1900 4 826 1900 4 826 Side Clearance Ring Groove 0025 635 0025 635 0030 076 0030 076 Ring End Gap 010 254 010 254 020 ...

Page 72: ...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 9...

Page 73: ...25 312 7 925 312 7 925 312 7 925 312 7 925 313 7 950 313 7 950 313 7 950 313 7 950 313 7 950 Dia Crankshaft Conn 1 3750 34 925 1 3750 34 925 1 3750 34 925 1 3750 34 925 1 3750 34 925 Rod Journal 1 3755 34 938 1 3755 34 938 1 3755 34 938 1 3755 34 938 1 3755 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 Crank Bearing Shaft Seat Dia for 1 1865 30 1...

Page 74: ...ROSS REFERENCE LIST CROSS REFERENCE LIST Craftsman Engine Model See Model Craftsman Engine Model See Model 143 626272 OH160 143 630012 OH160 143 630022 OH160 143 640012 OH160 143 640022 OH160 143 640032 OH160 143 640042 OH160 143 640052 OH160 143 650012 OH160 143 650022 OH160 143 650032 OH160 143 660012 OH160 143 660022 OH160 143 670012 OH140 143 670032 OH160 143 670042 OH140 143 670052 OH160 143 ...

Page 75: ...inder 1 4 96 120 10 9 13 6 Starter Recoil Top Mount 40 60 4 5 6 8 Starter Electric Straight Drive 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 ...

Page 76: ...ecumseh 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 relat...

Page 77: ...75 ...

Page 78: ...AMER No 670284 HH VH80 120 and OH120 180 VIBRATION TACHOMETER No 670156 Vibration Tachometer AIR GAP GAUGE No 670216 Air gap gauge 0075 191 mm shim stock for setting air gap VALVE LAPPING TOOL No 670154 Valve lapping tool No 670305 Strap Wrench No 670117 Ring Expander ...

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