Aen Aenl Aens Instr Parts

8/7/2019 Aen Aenl Aens Instr Parts

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Wisconsin Motors, LLC2020 Fletcher Creek Dr.Memphis, TN 38133

Ph 901-371-0353 or 800-932-2858Fax 901-372-2183

.Yi''W. wisconsinmotors.com


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IMPORTANTREAD THESE INSTRUCTIONSCAREFULLY

SERVICEFACIUTIESWISCONSINMOTORSDistributors and Service Centers, located throughoutthe U.S. and foreigncountries,havebeencarefully selectedto insurecompleteandefficient repair andinspectionservicto ownersof WISCONSINMOTORSEngines. Theseservice centers, equippedand staffed forcompleteenginerepair, also stockengineparts to facilitate immediatedeliveryfor the completelineof WISCONSINMOTORSEngines.

STARTING AND OPERATING OF NEW ENGINESCarefulbreakingin of a newenginewill greatlyincreaseits life andresult in trouble-freeoperation.Afactorytest is notsufficientto establishthepolishedbearingsurfaces,whichareso necessaryto thepropperformanceandlong life of anengine.Neitheris therea quickwayto forcethe establishmentof goobearingsurfaces.Thesecan only be obtainedby runninga newenginecarefully andunderreducespeedsandloadsfor a short time, as follows:First, besurethe engineis filled to the properlevel witha goodquali~of engineoil, see"Gradeof Oil"chart.Beforea newengineis put to its regularwork,the engineshouldbe operatedat low idle speed(100to 1200R.P.M.)foronehalf hour, withoutload. TheR. P. M. shouldthenbe increasedto engineopespeed,still without load, for an additional ~o hours. If at all possible,operatethe engineat light loads,for a periodtotaling abouteighthours,beforemaximloadis applied.Thiswill greatlyincreaseenginelife.Thevariousbearingsurfacesin a newenginehavenot beenglazed, as they will be with continueoperation,andit is in this periodof"runningi "n, that specialcaremustbeexercised,otherwisethe highldesired glaze will never be obtained. A newbearing surface that has oncebeen damagedbycarelessnesswill be ruinedforever.Ourenginewarrant,/is printedon the insidebackcoverof this manual.Readit carefully.For yourownrecordandfor orderingpurposes:

MODEL II SPECIFICATION SERIAL NUMBERTHEABOVEINFORMATION,WHICHWILL BE FOUNDON THEINSTRUCTIONPLATEATTACHTOTHEAIR SHROUDOFTHEENGINE,SHOULDBE FILLEDIN. YOURPROMPTATTENTIONTOTHISMA-FrERWILLMAKEIT CONVENIENTFORYOUIN THEFUTURE,AS THIS INFORMATIONMUSTBEGIVENWHENORDERINGENGINEREPAIRPARTS.


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BOOK OF INSTRUCTIONS

WISCONSINSINGLE CYLINDER ENGINES

READ THE STARTING AND OPERATING INSTRUCTIONS THOROUGHLY BEFORESTARTING A NEW ENGINE. BECOMEACQUAINTED WITH THE ENGINE COMPONENTS;THEIR LOCATION, MAINTENANCEAND ADJUSTMENTREQUIREMENTS.NOTE:MODELS AEN and AENS ARE OBSOLETE and WERE REPLACED BY MODEL AENL.ALL SERVICE REPLACEMENT PARTS FOR MODEL AENL CAN BE APPLIED TOMODELSAEN and AENS.FLYWHEELALTERNATORInstructions and Parts List ore located in the rear section ofthis manual.

Models AENLAEN, AENS

ISSUE WM20253

3" Bore - 3-1/4" Stroke23 cu. in. Displacement

The AENL engine with LONGLIFE exhaust valve and seat insert has the letterD suffixed to the model designation and is referred to as the Model AENLD.

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INDEXPAGE

AirCleaners.......................................................... 9Alternator -Rear of Manual.BatteryIgnition- Timing.................................... 12NeontampTiming.................................... 13CarburetorAdjustment........................................ 9Carburetor Repair - See ManufacturersBulletinin Rear of Manual.ClutchTake-Off.................................................... 14ClutchAdjustment................................................ 15Cooling.................................................................. 7Compression.......................................................... 17Compression- Restoring.................................... 14CrossSectionof Engine...................................... 6DisassemblyandReassembly............................ 18AirShroud........................................................ 19Camshaft.......................................................... 23CarburetorandAir Cleaner.......................... 19ConnectingRodandPiston.......................... 20Crankshaft...................................................... 22Cylinder.......................................................... 22CylinderHead............................................... 19EngineBase.................................................... 20Flywheel.......................................................... 18FuelTank........................................................ 18

OilPump.......................................................... 20Piston, Ring and RodClearanceChart ...... 22PistonRings................................................. 21StarterSheave................................................ 18Valves,GuidesandSeatInserts.................. 22ElectricWiringCircuits...................................... 13Fuel........................................................................ 8FuelPump............................................................ 10FuelStrainer........................................................ 10GearTrain............................................................ 22GeneralDesign................................................... 7GeneratorandTimerMaintenance...................... 13GovernorAdjustment............................................ 24Governor- Description- Operation.................... 23HighTemperatureSafetySwitch........................ 14Horsepower............................................................ 7

PAGEIgnition.................................................................. 7IgnitionSwitch.................................................... 10Illustrationof Engine.......................................... 4-5lubrication.......................................................... 7lubricationSystem.............................................. 7Magneto- BreakerPoint Adjustment................ 11MagnetoIgnitionSpark........................................ 11MagnetoRepair - SeeManufacturers Bulletinin Rear of Manual.MagnetoTiming.................................................... 11Motor-GeneratorOperatingInstructions............ 13Oil- Gradeof ...................................................... 8PartsListSection.............................................. 27ReductionGears.................................................. 15Rotation................................................................ 7SafetyPrecautions.............................................. 2Service CenterDirectory - Rear of Manual.SparkPlug............................................................ 14StartingandOperatingInstructions.................. 7Starting and Operation of NewEngine (SeeInside of Front Cover)Starting - RopeStarter - Starting Procedure.... 8StoppingEngine................................................ 9Storageof Engine................................................ 16Testingof RebuiltEngine.................................. 18Troubles-CausesandRemedies...................... 16BackfiringThroughCarburetor.................... 18Ignition............................................................ 17Knocking........................................................ 18Missing............................................................ 17Overheats........................................................ 18StartingDifficulties...................................... 16Stops................................................................ 17Surgingor Galloping...................................... 17Valves-GrindingandTolerances.................... 22ValveTappet- Adjustment................................ 23Warm-UpPeriod- Overspeeding........................ 9

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IGNITION CABLE

OIL BATHAIR CLEANER SPARK PLUG

VALVE TAPPETINSPECTIONCHOKE LE~(CLOSED) SPRING

CARBURETORNEEDLE VALVE

MAGNETOSTOP SWITCHTIMINGINSPECTION PLUG

MAGNETOBREAKER COVER

MI-887

Fig. ICARBURETOR=n,:l MAGNETOside view of ENGINE4

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AIR VENT HOLE

GASOLINE STRAINER3FF VALVE

~FLYWHEELSHROUD

HOLE AT VERCENTER, FOR TIMING.SLOTTED HOLE FCRUNNING SPARKADVANCE "rIMING

OIL FILLER P

OIL DRAIN PLUG~ ~

ROPE STARTERSHEAVE

Fig. 2FUELTANKside of ENGINE

5

287041C

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0Z

00I11m

mZm

OIL BATHAIR CLEANER\\\\

SPLIT- SKIRTPISTONSPLITSIDEOFPISTONTOWARDMANIFOLDCAM- GROUNDPISTONVALVETAPPETINSPECTIONPLATE~-_

CARBURETOR

MAGNETO

GROUNDING

TIMINGINSPECTIONPLUG

FUELPUMf

VALVEPISTON~\

AIR V[NT HOLE~~FUEL TANK/ CONNECTINGROD

\OIL STRAINER

CAMSHAFT~

GOVERNORASSEMBLY\FUELSTRAINER

\ SHUT-OFFVALVE

~RNORSPRINGADJUSTINGSCREWSPRING

OIL FILLERPLUG

OIL BRAINPLUG/CRANKSHAFT/ OIL PUMP"

SPARKPLUG

~ ]~L~. ~P ~STARTINGRO

~AIR SHROU

JROPESTAR/ SHEAVE

FAN-FLYWHEEL


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GENERALDESIGNWisconsin engines are of the four cycle type, in whicheach of the four operations of suction, compression,expansion and exhaust constitutes a complete stroke.This produces one power stroke for each two revolu-tions of the crankshaft.COOLINGCooling is accomplished by a flow of air, circulatedover the cylinder and head of the engine, by a combi-nation fan-flywheel encased in a sheet metal shroud.The air is divided and directed by ducts and baffleplates to insure uniform cooling of all parts.

Never operate an engine with any part of theshrouding removed- this will retard air cooling.Keep the cylinder and head fins free from dirtand chaff. Improper circulation of cooling air willcauseengine to overheat.

CAR BURETORThe proper combustible mixture of gasoline and airis furnished by a balanced carburetor, giving correctfuel to air ratios for all speeds and loads.GOVERNORA governor of the centrifugal flyball type controls theengine speed by varying the throttle opening to suitthe load imposed upon the engine. These engines areequipped with either a fixed speed or variable speedcontrol, to regulate the governed speed of the engine.IGNITIONThe spark for ignition of the fuel mixture is furnishedby a high tension magneto driven off the timing gearsat crankshaft speed. The magneto is fitted with animpulse coupling, which makes possible a powerfulspark for easy starting. Also, the impulse couplingautomaUcally retards the spark for starting, thus elim-inatingpossible kick back from engine while cranking.

Fig. 4 141162C-1

Battery ignition (12 volt) timer, is furnished in placeof magneto on engines equipped with flywheel alter-nator or generator.LUBRICATION SYSTEM(Fig. 4)A plunger type pump supplies oil to a spray nozzlewhich directs an oil stream against the connectingrod. Part of the oil enters the rod bearings thru holesin the rod, and the balance of oil forms a spray ormist which provides ample lubrication for all internalfriction surfaces of the engine.ROTATIONThe rotation of the crankshaft is clockwise whenviewing the flywheel or starting end of the engine.This gives counter-clockwise rotation when viewingthe power take-off end of the crankshaft.

HORSEPOWERR.P.M. HORSEPOWER16001800200022002400260028003000320034003600

4.75.46.16.87.47.98.58.99.29.29.2Horsepowergiven in the accompanying chart is for anatmospheric temperature of 60 Fahrenheit at sealevel and at a Barometric pressure of 29.92 inchesof mercury.For each inch lower Barometer reading deduct 3%from above horsepower.For each 10 higher temperature there will be a re-duction in horsepower of 1%.For each 1000 ft. altitude above sea level, there willbe a reduction in horsepower of 3%.The friction in new engines cannot be reduced to theultimate minimum during the regular block test, butengines are guaranteed to develop atleast 85 per centof maximum power when shipped from the factory. Thepower will increase as friction is reduced during afew days of operation. The engine will develop .atleast 95% of maximumhorsepower when friction is re-duced to a minimum.For continuous operation, allow 20% of horsepowershown, as a safety factor.

INSTRUCTIONSFORSTARTINGAND OPERATINGLUBRICATIONBefore starting a new engine, fill crankcase base withthe proper grade of engine oil, as specified in "grade

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o[ oil chart ~. Fill thru the filler plug opening, illus-trated in Fig. 4, to the level of the hole. The crank-case capacity is 3 pints.For run.in of new engines, use same oil as recom-mendedin Grade of Oil Chart.Use only high-grade highly refined oils, correspondingin body to the S. A. E. (Society of Automotive En-gineers) Viscosity Numbers listed in Grade of OilChart. These will prove economical and assure longengine life.SERVICE CLASSIFICATION OF OILIn addition to the S.A.E. Viscosity grades, oils are alsoclassified according to severity of engine service, useoils classified by the American Petroleum Institute asService SE or $~ This type of oil is for enginesperforming under unfavorable or severe operatingconditions such as: high speeds, constant startingand stopping, operating in extreme high or lowtemperatures and excessive idling.

GRADE OF OILSEASONOR GRADETEMPERATURE OF OIL

Spring, Summeror Autumn SAE 30 120Fto -t- 40F

Winter+ 40F to + 15F SAE20-20W+ 15F to 0F SAE 10WBelow Zero SAE5W-20

Useoils classified as Service SE or SFCrankcaseCapacity 3 Pts.

Follow summer recommendations in winter if engineis housed in warm building.Check oil level every 8 hours of operation.The old oil should be drained and fresh oiladded after every 50 hours of operation.

To drain oil, remove drain plug illustrated in Fig. 4.Oil should be drained while engine is hot, as it willthen flow more freely.FUELThe fuel tank should be filled with a good qualitygasoline free from dirt and water. The capacity of thetank is |~ gallons. Some of the poorer grades of gas-oline contain gum which will deposit on valve stems,piston rings, and in the various small passages inthe carburetor, causing trouble in operating, and infact might prevent the engine from operating at all.

Use only reputable, well known brands of gas-oline of the REGULARGRADE.The gasoline should have an octane rating of at least90. Fuel with a low octane rating will cause detona-tion, and if operation is continued under this condi-tion, severe damage will result to the engine. The

cylinder and piston will be scored, head gasket blownout, bearings will be damaged, etc.Be sure that air vent in fuel tank cap is not pluggedwith dirt, as this would impede the flow of gasolineto the carburetor.

STARTINGROPE STARTER (Fig. 5)This engine is equipped with a rope starter, whichhas an advantage over a starting crank in that a pullon the rope will give two full revolutions of thecrankshaft. This will result in easier starting, espe-cially if direct connected loads are coupled to theengine, such as generators, compressors, or beltedequipment, and when no clutch is used.STARTING PROCEDURE1.

2.:3.4.

So

Check crankcase and air cleaner oil level, andfuel supply. Open fuel valve.If applicable, open high speed needle valve oncarburetor 1 turns (See "Carburetor-A djustm ent).Disengage clutch, if furnished.Set throttle about 1/2 open if variable speed gov-ernor control is furnished. With a fixed speed gov-ernor, spring will hold throttle open for starting.Close choke on carburetor and turn engine overonce. Open choke half-way, turn engine over tocompression with starter sheave and then turn backone-half turn. Wind rope fully on sheave and pullbriskly to turn crankshaft over.

Fig. 5 140443C-1

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With starting motor, pull out ignition switch anddepress starter button.6. After engine starts, open choke fully. Less chok-ing is necessary in warm weather or when engineis warm, than when it is cold. Should flooding oc-cur, open choke fully and continue cranking.If all conditions are right, engine will start promptlyafter one or two attempts. After engine starts, allowit to warm up a few minutes, before applying load, asprescribed in Worm.Up Period paragraphs.New engines should be "run-in" gradually to insuretrouble-free service. Refer to "Starting and Operationof New Engine", on the inside frontcover of this man-ual, for correct "running-in" procedure.CARBURETORADJUSTMENT (Fig. 6)The main metering jet in the standard engine carbure-tor is of the fixed type and therefore no adjustmentcan be made.On engines with an adiustoble let carburetor, the highspeed needle valve should be opened to 1 turns.With the engine warmed up and running at normaloperating speed, the needle valve should then be re-adjusted for best operation. This adjustment needonly be made the first time the engine is started. Incold weather, starting may be facilitated by openingthe needle valve slightly more, then readjusted tonormal running position after engine is started.

THROTTLE PLATE IDLE ADJUSTMENT

FUEL

CHOKE LEVEROPTIONALFUELINLET HIGH SPEEDNEEDLE VALVE

THROTTLESTOP ADJUSTMENT

Fig. 6 289224C

The correct amount of throttle plate opening for lowidle speed is obtained by means of the throttle stopadjustment. However, this is set at the factory sothat no further adjustment is necessary. The idle ad-iustment is for smooth low speed operation and thisadjustment, if necessary, must be made with thecarburetor throttle lever closed.For further information, refer to carburetor serviceinstructions in the rear of this manual.WARM-UP PERIODThe engine should be allowed to warm up to operatingtemperature before load is applied. This requires onlya few minutes of running at moderate speed. Racingan engine or gunning it, to hurry the warm-up period,is very destructive to the polished wearing surfaceson piston, rings, cylinder, beatings,etc., as the pro-per oil film on these various surfaces cannot betablished until the oil has warmed up and become suf-ficiently fluid. This is especially important on newengines and in cool weather.Racing an engine by disconnecting the governor, orbydoing anything to interfere with the governor controlledengine speed, is extremely dangerous. The governoris provided as a means for controlling the enginespeed to suit the load applied, and also as a safetymeasure to guard against excessive speeds, whichnot only overstrain all working parts, but which mightcause wrecking of the engine and possible iniury tobystanders.Strict adherenceto the above instructions cannot betoo strongly urged, and greatly increased engine lifewill result as a reward for these easily appliedrecommendations.

STOPPING ENGINEEngines with magneto ignition have a lever typeground switch on the side of the magneto. To stop,depress lever and hold down until engine stops. SeeFig. 1. Battery ignition engines are furnished with anignition switch, "To Stop Push In".If the engine has been running hard and is hot, do notstop it abruptly from full load, but remove the loadand allow engine to run idle at 1000 to 1200 R.P.M.for three to five minutes. This will reduce the internaltemperature of the engine much faster, minimize valvewarping, and of course the external temperature, including the manifold and carburetor will also reducefaster, due to air circulation from the flywheel.

MAINTENANCEAIR CLEANERSAENLengines are provided with a dry element typeair cleaner, as illustrated in Fig. 7A, with the pre-viously standard oil bath air cleaner, Fig. 7, now fur-nished as optional equipment.

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The air cleaner must be serviced frequently, depend-ing on the dust conditions where engine is operated.Daily attention to the air cleaner is one of the mostimpo,rtant considerations in prolonging engine life.OIL BATH AIR CLEANER, (Fig. 7)Once each week; the filtering element should bethoroughly washed in a solvent. Remove oil and cleanout air cleaner bowl. Add fresh oil to the level lineindicated on bowl, using the same grade oil as is usedin the crankcase.Service daily, if engine is operating in very dustyconditions. Detailed instructions are on air cleaner.

Operating the engine under dusty conditions with-out oil in the air cleaner or with dirty oil, maywear out cylinder, piston, rings and bearings in afew days time, and result in costly repairs.DRY ELEMENT AIR CLEANER, (Fig. 7A)Service daily, if engine is operating in very dustyconditions. Remove cartridge and shake out the ac-cumulated dirt (do not tap or strike element - it maybecome damaged). Wipe out dirt from inside cover.Once each week; the filtering cartridge should betaken out and rinsed under a faucet with cold water,then wash by repeated dipping for several minutes ina solution of lukewarm water and a mild, non-sudsingdetergent. Rinse in cold water from the inside out,and allow to dry overnight before installing. In coldweather, protect element from freezing until dry. Ex-cessive smoke or loss of power are good indicationsthat the element requires cleaning.Do not use gasoline, kerosene or solvent for cleaning- Do not oil element.After five washings or one year of service, replacecartridge. New cartridges are available at your Wis-consin Motordealer.

COVER ANDFILTERING ELEMENT

AIR CLEANERBOWL

Fig. 7 208064C

311 747C

Fig. 8 208072CFUEL STRAINERA fuel strainer is very necessary to prevent dirt fromentering the carburetor and causing trouble, or evencomplete stoppage of the engine.The strainer is an integral part of the shut-off valve atthe bottom of the tank. Remove and clean periodically.A glass bowl fuel filter, Fig. 8, can be furnished inplace of the shut-off valve strainer. When dirt andwater accumulate the glass bowl and screen can beeasily removed for cleaning. Twist bowl when remov-ing to prevent damage to the gasket. Replace gasketif it has become damaged or hardened. Repair kits areavailable for service replacement, refer to parts list.FUEL PUMPFuel pump is an optional accessory and can be fur-nished only upon request when engin.e is purchasedfrom the factory. Instructions for fuel pump main-tenance and repair are located in the back of manual.IGNITION SWITCHMagneto ignition is standard on these engines, witha lever type ground switch on the side of the mag-neto, which is always in the on or running position,

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except when depressed for stopping the engine. SeeFig. l for location of stop switch.

MAGNETOBREAKERPOINTADJUSTMENT(Figs. 9, 10)Magnetos are properly adjusted and timed beforeleaving the factory. The breaker point gap of the Fair-banks-Morse magneto and Wico magneto should havean opening of .015 inch at full separation. If the sparkbecomes weak after continued operation, it may benecessary to readjust the breaker points. To do this.first remove the end cover on the magneto. See l~igs.9 and lO which show the end cover removed and thebreaker points of the magneto exposed. The followinginstructions are for the Fairbanks-Morse magneto, butcan be applied to the Wico magneto as well. Thecrankshaft should be rotated by turning the startingrope sheave by hand (this also rotates the magneto),until the breaker points are wide open. The openingor gap should then be measured with a feeler gauge.~md if necessary reset as shown in Fig. 9. To re-adjust points, first loosen the locking screws on thecontact plate enough so that the plate can be moved.Insert the end of a small screw driver into the odiust-ing slot at the bottom of the contact plate and openor close the contacts by moving the plate until t~.eproper opening is obtained. After tightening the lock-ing screws, recheck breaker point gap to make sure

it has not changed. If it is found that the breakerpoints have become rough, they should be smoothedwith a breaker point file before the above adjustmentsare made. Replace magneto end cover and gasketcarefully, so that it ~ill seal properly. For furtherinformation see Fairbanks-t,,~orse or ~/ico MagnetoMaintenanceInstructions in the rear of this manual.MAGNETOIGNITION SPARK (Fig. 11)If difficulty is experienced in starting the engine orif engine misses firing, the strength of the ignitionspark can be tested as follows: Remove the ignitioncable from the spark plug and then wedge a piece ofstiff bare wire up into the terminal boot with one endo the wire extending out. With the extended wire held9bout 1/8 inch away from the cylinder head shroud~tud, as shown in Fig. ll, turn the engine over slow-

WIRE1/8"

Fig. 9

CONDENSERMEASURE BREAKERPOINT GAP WHENOPEN. ADJUST TO.015 INCHFULCRUM PIN RINGBREAKER ARMLOCKING SCREWS

TERMINAL SCREW

END VIEW OF FAIRBANKS-MORSEMAGNETOF~g. 10

Fig. 11 140450C-2ly by means of the rope starter sheave. When the im-pulse coupling in the magneto snaps, there should bea good spark at the wire to stud gap. If there is aweak spark or no spark at all, check breaker pointgap as explained in the preceding paragraph. If thisdoes not remedy the trouble, refer to magneto manu-facturers maintenance instructions in the rear sectionof this manual for condenser replacement and furtherservice procedures.MAGNETOTIMING (Figs. 12, 13, 14)If it becomes necessary to remove the magneto forcleaning or repairs, it is important that the magnetobe reassembled properly so that it is timed correctlyto the engine.,~.emoval of the rope sheave an,! air intake screen onthe flywheel shroud, will expose the timing marks onthe shroud and flywheel, as shown in Fig. 12. It ishowever, possible to time the magneto to the enginewithout removing the flywheel screen. A 3/8" dia.hole in line with the vertical center is located in thealrintake screen as illustrated in Fig. 13. The markedair vane on the flywheel is visible thru this opening.1. Remove spark plug to make cranking easier.2. Turn engine over with the starter sheave until theedge of the D-C and X marked vane on flywheel isin line with the mark on the vertical centerline of


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RUNNINGSPARKADVANCETIMING HOLEFORCHECKIbWITHA NE(LIGHT

ENGINE ROTATIC(CLOCKWISE) FLYWHEELAIR SHROUDFig. 12 z08068C-1

Fig. 13 287043C

MARKED GEAR TOOTH VISIBLETHRU OPENING WHENFLYWHEELIS LOCATEDAS SHOWNIN FIG. 12Fig. 14 208069C

the shroud as shown in Fig. 12, or in the center ofthe timing hole as illustrated in Fig. 13.3. Leave the flywheel in this position. At this pointthe keyway for mounting the flywheel is on top.4. Mount magneto to engine, meshing the gears so thatwhen the magneto is in place, the X marked toothon the magneto gear will be visible in the center ofthe inspection hole of the crankcase as shown in

Fig. 14.

~OOILRETURNHOLE(IF APPLICABLE)

BREAKERPOINTSJUST STATIONARYCONTACTBEGINNINGTO OPEN. --~ LOCKNUT\RUBBINGBLOCK ~ OILER \~

Fig. 15, IGNITIONTIMERWhen the magneto is properly timed, the impulsecoupling will snap when the DC marked vane of theflywheel, lines up v~th the vertical centerline mark onthe flywheel shroud, or with the timing hole in air in-take screen, while turning the engine over slowly withthe rope starter sheave.The running spark advance is 20. For checking tim-ing with a neon light, the running spark advance isindicated by a slotted hole on the flywheel screen rim,as shown in Fig. 13. The center of the radii for theright handedge of the slotted hole is 20 or |~ inchesbefore the vertical center of the cylinder.

BATTERY IGNITIONTIMING(Figs. 12, 13, 15)Ignition timer is used in place of a magneto, when 6or 12 volt separate starter and generator is used.Time engine or check timing in the following manner:The ignition timer breaker point gap should be .020inch. This opening must be checked before the timerbody is set, otherwise any adjustment made to thebreaker point opening will change the ignition ad-vance adjustment. To readjust the breaker point gap,turn the engine over by means of the rope startersheave so that the ignition timer breaker arm rubbingblock is on a high point of the cam. Loosen the sta-tionary contact locknut and screw fixed contact, in orout, until correct gap of .020 inch is obtained. Tightenlocknut and recheck gap. See Fig. 15.Timing marks on the flywheel and shroud are exposedwhen the rope starter sheave and air intake screenare removed, as illustrated in Fig. 12. tlowever, a3/8" din. hole on the vertical center and a slottedhole to the left, on the rim of the a~r intake screen asshown in Fig. 13, makes it possible to time the en-gine without removing the sheave and screen, if sodesired.1. ~emove spark plug to make cranking easier.2. Turn engine over with the starter sheave until theedge of the D-C and X marked vane on the fly-

wheel is in line with the mark on the vertical cen-terline of the shroud as shown in Fig. 12, or inthe center of the 3/8" timing hole as shown inFig. 13.


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3. Leave flywheel in this position, for mountingignition timer assembly.

4. Assuming the timer assembly is removed from theengine, turn cam, by means of drive gear, in acounter-clockwise direction until breaker pointsare just beginning to open. Mount timer assemblyto engine, being sure that oil return hole in adapteris in the downward position, see Fig. 15.

5. Since the running, spark advance of the engine is20, and the timer automatic advance is 15, aninitial advance setting of 5 must be obtained.6. With the timer assembly mounted in place, loosenthe clamp lever screw. Obtain the intial 5 advance

as follows; with the breaker points just beginningto open, turn timer body in a clockwise directionthrough an angle of 5, which is equal to 1/8 inchon the outside circumference of the timer body.Tighten clamp lever screw.

7. Mount timer cover and connect primary wire fromignition timer to coil. See wiring diagram, Fig. 16.

If care is exercised in the above operations, the sparktiming will be accurate enough for satisfactory start-ing, however, the running spark advance must bechecked with a neon lamp, as described in "Neo~Lamp Timing paragraph.NEON LAMP TIMING FOR TIMER IGNITIONChalk or paint the end of the X marked vane on theflywheel, white. Then, with the engine operating at1800 R.P.M. or over, allow the flash from the neonlamp to illuminate the whitened vane. At the time ofthe flash, the leading edge of the vane should line upwith the running spark advance timing hole on theflywheel shroud, shown in Fig. 12, or the correspond-ing 20 location in the slotted hole of the air intakescreen rim, as shown in Fig. 13. If it does not, theclamp lever screw, shown in Fig. 15, should beloosened and the timer body turned slightly clock-wise or counter-clockwise, as required, until the ad-vance timing mark and the white vane coincide. Besure clamp lever screw is then securely tightened.Do not time engine below 1800 R.P.M. The automaticadvance in the ignition timer will not be fully ad-vanced and the timing would not be accurate.GENERATOR AND TIMER MAINTENANCEThis model of engine can be equipped with either a12 volt combination motor.generator or separate 6 and12 volt starter and generator. Battery is not furnished.The generator, motor-generator, and ignition timershould be periodically lubricated and inspected forexternal conditions which would affect their oper-ation. Motor-generators without oilers have pre-lub-ricated bearings. It is; recommended that the generatorand motor-generator oilers be given 3 to 5 drops ofmedium engine oil after every 50 hours of operation.

STARTERSWITCH BATTERY~, SpPLARK

REGULATORi_ } hi ~,~. ~ /~._~ ~[~-~(12 VOLT}

",GNITIO~SWITCH ....

C~~ ~-~ SWITCH ~ I I

_z GENERATOR GENERATOR

Fig. 16, STARTER AND GENERATOR WIRING

f ~~--I~ VOLTAGEREGULATOR

[ ~ AMMETER

IGNITIONSWITCH

Fig. 17~ COMBINATIONMOTOR-GENERATORWIRINGInspect the brushes for wea~, approximately every 200hours of operation. If they are worn to less than halftheir original length, they should be replaced.The oiler on the ignition timer and felt wick in thecam sleeve should have 3 to 5 drops of mediumengine oil every 100 hours of operation.ELECTRICAL WIRING CIRCUITSNOTE:Beginning with engine serial No. 3991018,the standard wiring circuits for all 12 volt electricalequipment is negative ground polarity, instead of thepreviously furnished positive ground. All ~ voltsystems remain positive ground.The wiring diagrams, Fig. 16 and 17, illustratenegative ground circuits. If polarity of generator ormotor-generator is for a positive ground circuit(engines built previous to serial No. 3991018),terminal connections at ammeter, coil and battery arejust reversed from those illustrated.Do not use positive ground generator and regulator ina negative ground circuit, or vice versa. Polaritydoes not affect starting motor, timer and coil.MOTOR-GENERATOR OPERATING INSTRUCTIONSThe combination motor-generator functions as a crank-ing motor when the starting switch is closed. Whenthe switch is open and the engine is running, theunit will function as a generator. The generator out-

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CURRENT- VOLTAGEREGULATOR

~ ~

MOTOR SWITCHFig. 18

FIELDTERMINAL

MOTOR- GENERATOR

MOTOR-GENERATORREGULATORWIRINGput and circuit voltage for the various battery andoperating requirements are controlled by a current-voltage regulator mounted to the generator.The total electrical output of this 12 va/tcombinationmotor-generator is |2 amperes. However, all of thecurrent is not taken off of a single terminal. Thereare twa terminals on the current-voltage regulator,illustrated in Fig. l& for distributing the generatoroutput. One terminal is marked BAT and a wire isconnected from it to the battery, thru an ammeter. Theother terminal marked / is for the timer ignitionsystem, if applicable, and for operating lights or anyother customer accessory. For a continuous load, notmore than 5 or 6 amps should be taken from this ter-minal if engine has magneto ignition. With timerignition, maximum draw should be 3 or 4 amps, since2 amps is required for the ignition system. Currentfrom the L terminal is continuous and is not affectedby the regulator windings. Whereas, the current to theBAT terminal goes thru the regulator windings andis controlled to keep the battery charged.The ammeterin this circuit indicates only the currentgoing into the battery to keep it chargedanddoes notindicate the total generatoroutput. If it is necessaryto check the amount of current coming from the Lterminal, it will be necessary to put a second ammeterin the circuit between the L terminal and the load.Add the two values indicated on the ammeters to getthe total generator output.To check if the generator is charging, it is only nec-essary to observe the ammeter that is connected inthe battery circuit. If it shows a charge, the systemis functioning properly. If it shows a discharge, re-move the load connected to the L terminal until thebattery current is restored and the ammeter doesregister a charge.SPARK PLUG(Fig. 19)The spark plug gap should be thirty thousandths(.030) of an inch, and plugs should be kept cleanboth inside and out. If the porcelain insulator iscracked, replace with a new plug of correct heatrange, like Champion No. D-16J, AC No. C86 Com-mercial, or equal. The thread is 18 millimeter.

SET GAP

Fig. 19 104713C

Use a new gasket when mounting either old or newplug and thoroughly clean threads in cylinder headbefore installation. Tighten spark plug 25 to 30 ft.poundstorque in reassembly.RESTORING COMPRESSIONOn a new engine or one ~hich has been out of oper-ation for some time, the oil may have drained off thecylinder so that compression will be weak. This maycause difficulty in starting. To remedy this condition,remove the spark plug and pour about a fluid ounce ofcrankcase oil through the spark plug hole. Turn theengine over several times with the rope starter todistribute the oil over the cylinder wall. Assemblespark plug and compression should be satis factory.HIGH TEMPERATURE SAFETY SWITCHThe high temperature safety switch is an accessorymounted to the cylinder head bolt at the take-off endand toward the fuel tank side. This safety switch willautomatically stop the engine whenever cylinder headtemperatures become critically high.The switch is set by the manufacturer to operate ata predetermined temperature and consequently shouldnot be tampered with. If an extreme cylinder headtemperature causes the switch to automatically shortout the magneto or timer and stop the engine, awaiting period of about |0 minutes will be requiredbefore the switch has cooled off sufficiently to allowthe engine to be re-started. An overheated enginewill score the cylinder walls, burn out connecting rodand crankshaft bearings, also warp piston and valves.The cause of the overheating condition will have tobe remedied before the engine is re-started.

CLUTCHANDREDUCTIONGEARSCLUTCH TAKE-OFF (Fig. 20)The clutch in the take-off assembly, that can be fur-nished with this model of engine, is of the multipledisc type running in oil. Use the same grade of oil inthe clutch housing as is used in the crankcase. Theoil should be filled to the height of the oil levelplug in the clutch housing. Fill through the inspectionplate opening; about 1 pint of oil is required.

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. HEREION PLATE

OIL LEVEL PLUGOIL DRAIN PLUG

Fig. 20 140451C-I

OIL FILLERPLUG

OIL LEVEL PLUGOIL DRAIN PLUGFig. 21 140449C.1

REDUCTIONGEARS(Fig. 21 and Fig. 22)Reduction gears are furnished in several differentratios, some with spur gears, others with chains. Allare of the same general design, except that some arefurnished with clutches, others without.

Use samegrade all as used in engine crankcase.For different installations these gears are assembledto the engines in various positions. Several plugsare furnished on these reduction gears so that thelubrication may be properly taken care of regardlessof the position of installation. For instance, therewill always be one plug on top to be used for fillingoil. There will always be one plug below for drainingoil, and there will be one plug on the side, slightlyabove the bottom, to be used as an oil level plug. Theoil should always be filled when the engine is atrest. When the oil becomes dirty it should be drainedwhile the engine is hot, and fresh oil added. Thefrequency at which these oil changes should be madedepends entirely on the kind of service in whichthese gears are used, but even with light service;

FILL HEREPLATE

OIL DRAINPLUG

ADJUSTMENTLOCKSCREWHOLEFig. 22 140457C-1

ADJUSTMENTLOCKFig. 23Changeoil at least every 500 hours of operation.

Add sufficient oil between changes to keep oil up tothe oil level plug. The oil capacity for the reductionunit shown in Fig. 2l is 2/3 pint, and for the clutchreduction unit, Fig. 22, I pint.CLUTCH ADJUSTMENT(Fig. 23)If the clutch begins to slip, it should be readjusted toprevent it from becoming overheated and damaged.The clutch in the clutch take-off and clutch reductionunits is adjusted by first removing the clutch inspec-tion plate which will expose the notched adjustingring. Release the clutch, by pushing the engaginglever forward.

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Turn engine over by means of the rope starter sheave,until the clutch adjustment lock is visible thru theinspection opening of the housing. Loosen adjustmentIockscrew, one full turn. On take-off units, the lock-screw is accessible thru the pipe plug hole behindthe inspection opening.Keep the clutch from turning by holding the ropestarter sheave firmly in place with the left hand.Then, by means of a screw driver, turn the adjustingring one notch at a time in a clockwise direction,until a definite pressure is felt on the clutch leverwhen the clutch is being engaged. Securely tightenadjustment lockscrew. Assemble inspection plate,being sure that the gasket fits properly and is notbroken.

INSTRUCTIONSFOR PROTECTINGENGINESFOR WINTEROR SHORTSTORAGEPERIODSWhen the work interval is completed, the followinginstructions should be carried out very carefully toprotect the engine from the weather.The outside of the engine, including the cooling finson the cylinders and heads, should be thoroughlycleaned of all dirt and other deposits.The air cleaner at the carburetor intake should bethoroughly cleaned of all oil and accumulated dust,and the sediment removed from the oil cup at thebottom of the cleaner.To protect the cylinder, piston, rings and valvesand keep them from rusting and sticking, a half andhalf mixture of kerosene and good engine oil, (thesame kind of oil as used in the crankcase of the en-gine), should be injected into the pipe tap openingon the intake manifold while the engine is warm andrunning at moderate speed. About a quarter of a pintis necessary, or enough so that a heavy bluish smokewill appear at the exhaust. The ignition switch shouldthen be shutoff and the engine stopped. This foggingoperation will give a coating of oil on the abovementioned parts, protecting them from the atmosphere.After the engine has stopped, disconnect the sparkplug cable and turn engine over slowly thru the com-pression stroke until the flywheel key or take-offshaft keyway is up, or in the 12 oclock position.Both valves will be closed and the piston will be ontop in the cylinder bore, with the crankshaft in thedescribed position. This will minimize rusting of thecylinder bore and help in retaining the oil fog pre-viously injected into the engine.All old used oii should be drained from the crankcasewhile the engine is warm, as the oil will then flowmore freely than when cold.Drain fuel system, including gasoline lines, carbu-retor, fuel pump and tank of all gasoline, to preventlead and gum sediment interfering with future opera-tion. Gasoline fumes from gradual evaporation is adangerous fire hazard.The air cleaner or carburetor intake, as well as theexhaust manifold opening, should be taped or other-

wise sealed off, for the duration of the storage period.All exposed unpainted metal parts should be coatedwith grease or heavy oil.Before starting the engine, after the storage period,remove crankcase drain plug so that any condensa-tion which may have collected may be drained, beforenew crankcase oil is added. It is highly recommend-ed that the engine base be removed, and scrubbed ofall sediment which may have collected ~here. Whenreassembling the base, a new gasket should be used.

Be sure to fill crankcase with the correct gradeof oil to the level of the filler plug hole. Do notuse any oil heavier than SAE No. 30. Also besure to put oil to the proper level in the aircleaner. (Refer to Lubrication and Air Cleaner.)

It is advisable to use a new spark plug at the begin-ning of the operating interval, especially if the en-gine has given considerable service.!~efuel engine and follow the starting instructions asshown on preceding pages of this manual.

It is suggested that machines be stored insidea building. If this is not possible, the engineshould be protected from the weather by a propercovering.

TROUBLESCAUSESANDREI~EDIESThree prime requisites are essential to starting andmaintaining satisfactory operation of gasoline en-gines. They are:1. A proper fuel mixture in the cylinder.2. Good compression in the cylinder.3. Good spark, properly timed, to ignite the mixture.If all three of these conditions do not exist, the en-gine cannot be started. There are other factors whichwill contribute to hard starting; such as, too heavy aload for the engine to turn over at a low startingspeed, a long exhaust pipe with high back pressure,etc. These conditions may affect the starting, but donot necessarily mean that the engine is improperlyadjusted.As a guide to locating any difficulties which mightarise, the following causes are listed under the threeheadings: Fuel Mixture, Compression, and Ignition.In each case the causes of trouble are given in theorder in which they are most apt to occur. In manycases the remedy is apparent, and in such cases nofurther remedies are suggested.

STARTINGDIFFICULTIESFUEL MIXTURENo fuel in tank or fuel shut-off valve closed.Fuel pump diaphragm worn out, so pump does notsupply carburetor with fuel.

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Carburetor not choked sufficiently, especially if en-gine is cold. See "Starting Procedure, Page 8.Water, dirt, or gum in gasoline interfering with freeflow of fuel to carburetor.Poor grade or stale gasoline that will not vaporizesufficiently to form the proper fuel mixture.Carburetor flooded, caused by too much choking espe-cially if engine is hot.Needle valve on carburetor insufficiently opened.See Carburetor Adjustment, Page 9.Dirt or gum holding float needle valve in carburetoropen. This condition would be indicated if fuel con-tinues to drip from carburetor with engine standingidle. Often tapping the float chamber of the carbu-retor very lightly with the wood handle of a screwdriver or similar instrument will remedy this trouble.Do not strike carburetor with any metal tools, it maybe damaged. If the mixture in the cylinder, due toflooding, is not too rich to start the engine, startingshould be tried, as it will usually correct the trouble.In this case the choke should be left open.If, due to flooding, too much fueI should have enteredthe cylinder in attempting to start the engine, themixture will most likely be too rich to bum. In thatcase the spark plug should be removed from the cyl-inder and the engine then turned over several timeswith the starting sheave, so the rich mixture will beblown out through the spark plug hole. The chokeon the carburetor should of course be left open duringthis procedure. The plug should be dried off, assem-bled, starting tried again.To test for clogged fuel line, loosen fuel line nut atcarburetor slightly. If line is open, fuel should dripout at loosened nut.

COMPRESSIONIf the engine has proper compression, considerableresistance will be encountered in the pull on thestarting sheave. If this resistance is not encounter-ed, compression is faulty. Following are some rea-sons for poor compression:Cylinder dry dueto engine having been out of use forsome time. See "Restoring Compression, Page 14.Loose spark plug or broken spark plug. In this casea hissing noise will be heard in cranking engine dueto escaping gas mixture on compression stroke.Damaged cylinder head gasket or loose cylinderhead.This will likewise cause hissing noise on compres-sion stroke.Valve stuck open due to carbon or gum on valve stem.Removetappet inspection plate and note if valves aremoving up and down as engine is turned over by hand.A stuck valve will not follow down. To clean valvestems, see Valves, Page 22.Vatve tappets adjusted with insufficient clearanceunder valve stems. See Valve Tappets, Page 23.Piston rings stuck in piston due to carbon accumu-

lation, If tings are stuck very tight this will neces-sitate removing piston and connecting rod assemblyand cleaning parts. See Connecting Rod and Piston,Page 20.Scored cylinder. This will require reboring of thecylinder and fitting with new piston and rings. Ifscored too severely an entirely new cylinder crank-case may be necessary.IGNITIONSee "Magneto Ignition Spark, Page 1l or BatteryIgnition Timing, Page 12. No spark may also beattributed to the following:Ignition cable disconnected from magneto, time;, coilor spark plug.Broken ignition cables, causing short circuits.Ignition cable wet or oil soaked.Spark plug insulator broken.Spark plug wet or dirty.Spark plug point gap wrong. See Page 14.Condensation on spark plug electrodes.Magneto or Timer breaker points pitted or fused.Magneto or Timer breaker arm sticking.Magneto or Timer condenser leaking or grounded.Spark timing wrong. See llagneto Timing, Page 11,or "Battery Ignition Timing, Page 12.ENGINE MISSESSpark plug gap incorrect. See Page 14.Worn and leaking ignition cable.Weak spark. See Magneto Ignition Spark, Page ll,or Battery Ignition Timing, Page 12.Loose connections at ignition cable.Magneto or Timer breaker points pitted or worn.Water in gasoline.Poor compression. See Compression, Page 17.ENGINE SURGES OR GALLOPSCarburetor flooding.Governor spring hooked into wrong hole in lever, orgovernor rod incorrectly adjusted. See Governor Ad-fustment, Page 24.ENGINE STOPSFuel tank empty.Water, dirt or gum in gasoline.Gasoline vaporized in fuel lines due to excessiveheat around engine (Vapor Lock). See Stopping En-gine, Page 10.Vapor lock in fuel lines o~ carburetor due to usingwinter gas (too volaUle) in hot weather.Air vent hole in fuel tank cap plugged. Engine scoredor stuck due to lack of oil.

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Ignition t~oubles.SeeIgnition, Page17.ENGINE OVERHEATSCrankcase oil supply low. Replenish immediately.Ignition spark timed wrong. See Magneto Timing,Page 11, or Battery Ignition Timing, Page 12.Lowgrade of gasoline.Engine overloaded.Restricted cooling air circulation.Part of air shroud removedfrom engine.Dirt between cooling fins on cylinder and head.Engine operated in confined space where cooling airis continually recirculated, consequently becomingtoo hot.Carbon in engine.Dirty or incorrect grade of crankcase oil.Restricted exhaust.Engine operated while detonating due to low octanegasoline or heavy load at low speed.ENGINE KNOCKSPoor grade of gasoline or of low octane rating. SeeFuel, Page 8.Engine operating under heavy load at low speed.Carbon or lead deposits in cylinder head.Spark advanced too far. See Magneto Timing, Pagell, or "Battery Ignition Timing, Page 12.Loose or burnt out connecting rod bearing.Engine overheated due to causes under previousheading.Wornor loose piston pin.ENGINE BACKFIRES THROUGHCARBURETORWateror dirt in gasoline.Engine cold.Poor grade of gasoline.Sticky inlet valve. See Valves, Page 22.Overheated valves.Spark plug too hot. See Spark Plug, Page 14.Hot carbon particles in engine.

DISASSEMBLYANDREASSEt~BLYOF ENGINE

Engine repairs should be made only by a mechanicwho has had experience in such work. Whendisassem-blingthe engine, it is advisable to have several boxesavailable so that parts belonging to certain groupscan be kept together. Capscrews of various lengthsare used in the engine, therefore great care must be

exercised in reassembly so the right screw will beused in the proper place.Tighten the cap screws and nuts of the manifold,cylinder head, engine base, connecting rod, mainbearing plate and the spark plug to the specifiedtorque readings indicated in the paragraphs of reas-sembly, relative to these parts.While the engine is partly or fully dismantled, all ofthe parts shoald be thoroughly cleaned. Use all newgaskets in reassembly and lubricate all bearingsurfaces.The following procedure is for complete disassemblyof an engine. As disassembly progresses, the ordermay be altered somewhat, as will be self-evident tothe mechanic, l~eassembIy of the engine should bemade in the reverse order.TESTING OF REBUILT ENGINEAn engine that has been completely overhauled, suchas having the cylinder rebored and fitted with newpiston, rings and valves, should go through a thorougharun-in ~ period before any load is applied to theengine.The engine should be started and allowed to run forabout one-half hour, at about 1200 to 1400without load. The R.P.M. should then be increased toengine operating speed, still without load, for anadditional three and one-half to four hours.The proper grunning-in ~ of the engine will help toestablish polished bearing surfaces and proper clear-ances between the various operating parts and thusadd years of trouble free service to the life of the

ACCESSORIESOn engines furnished with clutch or reduction units,these should be removedfirst if the engine is to becompletely overhauled. Also remove muffler, sparkplug cable and electrical equipment.FUELTANK(Fig. 24)Disconnect fuel line at fuel strainer. Removecap-screws mounting the fuel tank bracket to the crank-case and cylinder head. The tank and bracket assem-bly can be removedas a unit.C),linder bead cover can also be removedat this time.ROPESTARTERSHEAVE(Fig. 25)The rope starter sheave can be loosened by a sharpblow against the handle of a wrench, fitted to thehexagon hub of the sheave, in a counter-clockwisedirection. Removesheave as shown in Fig. 25.FLYWHEEL(Fig. 26)Remove air intake screen by taking out the fourscrews which mount the screen to the shroud.The flywheel is mountedto a taper on the crankshaft.Take a firm hold on the flywheel fins, pull outward

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Fi~. 24 140436C-I

Fig. 25 140445C.1

Fig. 26 140448C-1and at the same time strike the end of the crankshaftseveral times with a babbitt hammer. The flywheelwill slide off the taper of the crankshaft. Do not usea hard hammer as it may ruin the crankshaft andbearings. Remove Woodruff key from crankshaft.In reassembly; be sure the Woodruff key is in positionon the shaft and that the keyway in the flywheel is

Fig. 27 140455C-1lined up accurately with the key. After mounting; seatflywheel on crankshaft taper by slipping a piece ofpipe over the end of the crankshaft and against thehub of the flywheel, and striking the end of the pipea sharp blow with the hammer.CARBURETORAND AIR CLEANER (Fig. 27)Loosen the fuel line at the carburetor and breatherline at the cylinder. Then, remove the cotter pin fromthe governor control rod and pull the rod out of thegovernor lever. Loosen and remove the capscrew andlockwasher which holds the air cleaner bracket tothe engine and the two capscrews and lockwasherswhich clamp the manifold to the cylinder. The entireassembly of the manifold, carburetor and air cleanercan then be removed as illustrated.In reassembly; tighten the screws for mounting themanifold to 9 foot pounds torque.AIR SHROUD(Fig. 28)Take out the four screws which mount the air shroudto the cylinder and cylinder head. Remove the twolower screws that fasten the shroud to lugs on thecrankcase and take off the air shroud as shown.CYLINDER HEADThe cylinder head must be removed if it is necessaryto regrind valves, or to work on the piston, rings orconnecting rod. All of the cylinder head screws areplainly in view and can be easily removed.Before reassembling the cylinder head, all carbon andlead deposits should be removed. It is recommendedthat a new cylinder head gasket be used in reassem-bly as the old gasket will be compressed and hardso that it may not seal properly. Use a mixture of

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OIL PUMP

Fig,29 140437C-Igraphite and oil on the cylinder head screws to pre-vent them from rusting tight in the block. Torquecylinder head screws to 32 foot pounds.ENGINE BASEand OIL PUMP(Figs. 29 and 30)Magnetocan be removed at this time to prevent itfrom becoming damaged while removing engine hase.Be sure oil is drained from base - place engine onits side and remove the twelve base to crankcase cap-screws and washers. In reossemhly, use a new basegasket - tighten capscrews7 to 9 foot pounds torque.Dismantle the oil pump by taking out the two cap-screws which hold it to the crankcase. All parts ofthe pump should be thoroughly washed in solvent toremove all tr~ces of thickened oil and sludge.

SPRAY

PLUNGEROIL PUMP

Fig.30 140435C-2The oilpump plunger is fitted to the bore with a clear-ance of .003 to .005 inch. If the clearance is greaterthan .008 inch, the plunger and oil pump body shouldbe replaced. Inspect the check ball seat in the bot-tom of the pump cylinder. This seat must be perfectlyclean, and must not be worn or pitted. The check ballshould be dropped into the cylinder and tapped intothe seat lightly. Insert retainer spring and plunger in-to bore.Before ~ssembling oil pump to crankcase, fill basepartially with engine oil and test the operation ofthe pump by working the plunger up and down asshown in Fig. 30.In reassembly; be sure push rod makes contact withplunger and the strainer screen is in good conditionand properly mounted. See oil pump in Fig. 32.CONNECTINGRODand PISTON(Figs. 31, 32, 33, 34)After removal of engine base and oil pump, the con-necting rod will be accessible. By means of a 1/2"socket wrench, loosen and remove hex locknuts fromthe rod bolts. Then, by tapping the ends of the boltslightly, the connecting rod cap will break free fromthe bolts.

Fig.31 140444C-1

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Fig. 32 141162C-ITHRUST FACE

WIDE THRUSTFACE TowardFuel TankSide of Engine

HOLE(Toward Oil Pump)

Fig. 33 287047CScrape off all carbon deposits that might interfere withremoval of pistons from upper end of cylinder. Turncrankshaft until piston is at top, then push connectingrod and piston assembly upward and out thru top ofcylinder, Fig. 31. Be careful not to mar the crank pinby allowing the rod bolts to strike or scrape across it.NOTE:This model of engine was originally furnishedwith babbitt cast cormecting rod bearings. Shell bear.ing rods are now being used for current production en-gines, and are interchangeable with babbitt bearingrods for service replacement. Care should be taken inreassembly to mount bearings properly. The capshould be assembled to the rod so that the locatinglug of both bearing halves are on the same side as il-lustrated in Fig. 34L Refer to chart, Fig. 37, forclearance between bearing and crank pin.Cam ground piston is mounted to the connecting rodwith the wide thrust Face, Fig. 33, opposite oil bole

LOCATING LUGSSTAMPEDNUMBERS

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