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Service Manual

1. SPRING 8 FLAT WASHER REED VALVE C 7 BREATHER 22 BAFFLE C 1003 FIGURE 3 CRANKCASE BREATHER PRESSURE LUBRICATION All engines use an oil pump to provide a constant flow of oil to the engine parts The oil supply collects in the oi base where it is picked up by the oil pump pick up cup A by pass valve is used to control oil pressure Drain oil before removing oil base and always use a new gasket when replacing the oil base Oil Pump The oil pump Figure 4 is mounted behind the gear cover and is driven by the crankshaft gear Inlet pipe and screen assembly are attached directly to the pump body discharge passage in pump cover registers with a drilled passage in the crankcase Parallel passages distribute oil to the front main bearing rear main bearing and pressure control bypass valve OIL PUMP PICK UP CUP OIL PUMP ASSEMBLY CRANKCASE TURNED ON LEFT SIDE LS 1109 FIGURE 4 OIL PUMP ASSEMBLY Circumferential grooves in the main bearings supply oil to connecting rod bearings through drilled pas sages from each main journal A drilled passage connects the front main bearing oil supply to the front camshaft bearing rear cam bearing is splash lubrica ted Oil overflow from the bypass valve furnishings lubrication to the camshaft drive gears Normal oil pressure should be 30 psi 207 kPa or higher when the engine is at normal operating temperature If pressure drops below
2. 9 9 EXHAUST VALVE Stem Diameter ERA Clearance Stem to Valve Angle LAG NAR EXHAUST VALVE SEAT Seat Bore Diameter Seat Outside Diameter Dev ov E OU Sea Valve Seat Width Valve Seat Angle B 9 9 4 9 0 9 9 9 V v B 9 9 b 9 9 4 5 8 8 9 B D S9 b 9 9 b 4 9 9 9 9 BP VALVE GUIDE Inside Mediates PEU MP TAPPET Body Diameter iater ee ka eese bt xm Kee p Bore vex icc ERN Rd e PA ORE ER S E ANA Clearance in Sese veo tok E ER queue eed e bed VALVE SPRINGS INTAKE AND EXHAUST Valve Spring Free Length Approx Valve Spring Length OPEN pude Eas A a 224i er EU Rt Gia ei x ep Gene Spring Load 1 375 inch Valve Spring Load 1 125 inch Valve GEAR BACKLASH Timing GOA dits uires OllPump Goal GOVERNOR Dashpot to Governor Arm MINIMUM Inches
3. 3 Ww PN M e Rr 4 4 p SS MOUNTING SCREWS LA FIGURE 1 SETTING POINT GAP 8 1 GEARCASE TIMING 7 Replace breaker box cover coil wire spark plugs and spark plug cables Timing Test As a check for proper ignition timing a continuity test may be performed 1 Adjust breaker points 2 Remove blower housing to expose timing marks on top of gearcase cover and flywheel Figure 2 S FLYWHEEL TIMING TC MARK MARKS Tj A M 1397 FIGURE 2 TIMING MARKS 3 Rotate flywheel clockwise unti timing mark is aligned with the proper number of timing degrees Figure 2 stamped on the top of gearcase cover Refer to SPECIFICATIONS for proper number of timing degrees 4 Connect an ohmmeter or a continuity test lamp set across the ignition breaker points Touch one test prod to the coil lead terminal screw B Figure 1 5 Touch the other test prod to a good ground on the engine 6 Turn crankshaft against rotation counterclockwise until the points close Then slowly turn the crankshaft with rotation clockwise 7 The lamp should go out or continuity lost just as the points break which is where ignition occurs if timing is early advanced the point gap is too large If timing is late retarded the point gap is too small Adjust point
4. Service Manual BASG BASG 965 0757 B43E Spec A D B43G Spec A D B48G Spec A G 6 88 Printed in USA Safety Precautions is recommended that you read your engine manual and become thoroughly acquainted with your equipment before you start the engine This symbol if used warns of imme diate hazards which will result in severe personal injury or death This symbol refers to a hazard or AA WARNING unsafe practice which can result in severe personal injury or death This symbol refers to a hazard or A CAUTION unsafe practice which can result in personal injury or product or property damage Fuels electrical equipment batteries exhaust gases and moving parts present potential hazards that can result in serious personal injury Take care in following these recom mended procedures All local state and federal codes should be consulted and complied with AWARNING This engine is not designed or in tended for use in any type of aircraft Use of this engine aircraft can result engine failure and causes serious personal injury or death General Provide appropriate fire extinguishers and install them in convenient locations Use an extinguisher rated ABC by NFPA Makesurethatallfasteners on the engine are secure and accurately torqued Keep guards in position over fans driving belts etc e Ifitis necessary to make adjustments while the engine is running use extrem
5. 1 Usethe proper bearing driverto install front main bearing after coating it with a light film of oil 2 Insert rear main bearing in rear bearing plate 3 Insert crankshaft rear bearing plate and crank shaft gear 4 Install piston and connecting rods 5 Install camshaft and gear assembly align crank gear mark with cam gear mark 6 Install valve assemblies oil pump oil base and cylinder heads 7 Install breaker point box 8 Install all accessories such as oil filter starter fuel lines and spark plugs 9 Install gear cover with oil seal and flywheel 10 Set breaker points to obtain proper timing 11 Check valve clearance 12 Install all housings and air cleaner 13 Fill crankcase with oil Operation Start engine and check oil pressure Run for approx imately 15 minutes to bring engine to operating temperature Check for oil leaks fuel leaks and exhaust leaks Adjust carburetor and governor for speed and sensitivity Testing Compression The compression tester is used to determine the condition of valves pistons piston rings and cylinders To check compression 1 Run the engine until thoroughly warm 2 Stop engine and remove spark plugs 3 Remove air cleaner and place throttle and choke in the wide open position 4 Insert the compression gauge in one spark plug hole 5 Crank the engine and note the reading Refer to SPECIFICATIONS section for compression pressures There may be variations due t
6. mm Inches 0 00004 0 0010 0 00064 0 0002 0 005 0 0007 0 6875 17 46 0 6877 0 003 0 076 0 008 0 010 0 254 0 020 0 3425 8 70 0 3430 0 0010 0 025 0 0025 44 1 4395 36 56 1 4405 1 443 36 65 1 444 0 031 0 787 0 047 45 8 561 0 3415 0 064 0 040 44 30 20 1 190 30 28 1 198 0 787 0 047 45 8 74 0 346 18 99 0 7480 19 06 0 7515 0 038 0 003 1 662 42 21 1 125 28 58 1 375 34 93 4216 32kg 7916 0 025 0 006 0 051 0 005 1 02 0 060 MAXIMUM mm 0 0162 0 018 17 47 0 203 0 508 8 71 0 064 36 59 36 67 1 194 8 674 0 102 30 23 30 30 1 194 8 79 19 00 19 09 0 076 19 kg 36 kg 0 152 0 127 1 52 Assembly Torques The torque values given in Table 1 have been deter mined for the specific applications Standard torque values must not be used where those listed Table 1 apply The engine assembly torques given here will assure proper tightness without danger of stripping threads Allthreads must be clean and lubricated with new engine oil before torquing Check all studs nuts and capscrews and tighten as required to keep them from working loose Refer to the PARTS MANUAL for the location of washers and Capscrews TABLE 1 TORQUE TORQUE DESCRIPTION SPECIFICATION DESCRIPTION SPECIFICATION Ft Lb Nm Ft Lb Nm Gearcase 8 10 11 14 Intake Manifold Mo
7. E 6 Table of Contents TITLE PAGE General Information 1 1 SPOCHICATIONS lt 2 1 Dimensions and Clearances 3 1 Assembly Torques and Special Tools 4 1 Engine Troubleshooting 5 1 6 1 duke 7 1 Ignition and Battery Charging 8 1 Starling System 5 9 1 Engine Disassembly 10 1 EXHAUST GAS IS DEADLY Exhaust gases from all fuels including diesel gasoline liquid propane natural gas contain carbon monoxide an odorless and colorless gas Carbon monoxide is poisonous and can cause unconsciousness and death Symptoms of carbon monoxide poisoning can include Dizziness Throbbing in Temples Nausea Muscular Twitching Headache Vomiting Weakness and Sleepiness Inability to Think Coherently IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS GET OUT INTO THE FRESH AIR IMMEDIATELY If symptoms persist seek medical attention Shut down the unit and do not operate until it has been inspected and repaired Protection against carbon monoxide inhalation includes proper installation ventilation and regular frequent visual and audible inspections of the complete exhaust system Redistri
8. ENDPLAY HERE REFER TO DIMENSIONS AND CLEARANCES FIGURE 23 CRANKSHAFT ENDPLAY Checking Bearing Clearance With Plastigauge The most accurate means of determining bearing clearance is by using micrometers However if crank shaft is installed in engine bearing clearance may be measured by using a plastic strip Plastigauge manu factured for this purpose 1 Make certain that all parts are marked or identified so that they are reinstalled in their original positions using a clean dry cloth thoroughly clean all oil from crankshaft journal and connecting rod 2 Place a piece of correct size Plastigauge in the bearing cap the full width of the journal surface and about 1 4 inch 6 35 mm off center Figure 24 3 Rotate the crankshaft about 30 degrees from bottom dead center and reinstall the bearing cap tighten rod bolts to the torque specified in ASSEMBLY TORQUES AND SPECIAL TOOLS Do not turn the crankshaft 4 Remove bearing cap The flattened Plastigauge will be found adhering to either the bearing cap or crankshaft 5 Compare flattened Plastigauge with the graduations on Plastigauge envelope to determine clearance The number within the matching graduation on the envelope indicates total clearance in millimetres or thousandths of an inch MOUNTING FACE OIL SEAL GEAR COVER 645 INCH FRONT 16 4 h D MA ICALI my TIRS OR 001 TO Gog c
9. FUEL SYST EM Out of Fue Check ee Eee DER I MEUS ie AEN 8 ME Dirty Carburetor 444444 Dirty AirCleaner 85 1 bmwfulFhe HE KJ M CANTERNAL ENGINE 2 Valve or Valve Seal Leaking COOLING SYSTEM AIR COOLED Poor Air Circulation Dirty or Otly Cooling Fins Blown Head Gasket m M etu MIL BOTE seers a Bese saree voeem ES Sn LUBRICATION SYSTEM Oil Too Heav Dirty Crankcase Breather Valve T UY DEPO M ad 111414 1 leje HEEN HKA Linkage Worn or Disconnected E Governor Spring Sensitivity Too Great tt tT tT IL I E 9 1 Redistribution or publication of this document by any means is strictly prohibited Oil System CRANKCASE OIL Refer to Periodic Maintenance Schedule located in the Operator s Manual for oil change interval If operating in extremely dusty high ambient or low ambient conditions change more often Hot crankcase oil can cause burns if AWARNING it comes in contact with skin Wear protective clothing and keep fingers and hands clear when draining oil Excess oil can cause high oil con ACAUTION sumption high operating temper atures and oil foaming Do not over
10. bearing journals for cracks if overheating has occurred Measure crankshaft main bearing and connecting rod journals at several places on their diameter to check for roundness and taper The only recommended method of reconditioning the crankshaft is regrinding as required to accommodate undersize bearings Metallizing of bearing journals is not recommended If regrinding of crankshaft journals is necessary the work should be done by a reputable machine shop that has suitable equipment to handle precision work of this type Undersize main bearings are available in sizes of 0 010 0 020 and 0 030 inch Undersize connecting rods are available in sizes of 0 010 0 020 0 030 and 0 040 inch Whenever making major repairs on the engine always inspect the drilled passages of the crankshaft Clean them to remove any foreign material and to assure proper lubrication of the connecting rods BEARINGS With camshaft and crankshaft removed use a micro meter to measure diameter of bearing journals Use a dial bore gauge or a telescopic gauge and micrometer to measure inside diameter of bearings Refer to DIMENSIONS AND CLEARANCES to determine if clearances are within specifications Any bearing that is scored chipped pitted or worn beyond the specified limits must be replaced Removal of the camshaft bearings requires complete disassembly of the engine Use a press or a suitable driver to remove bearings Support casting to avoid dis
11. by step removal disassembly inspection repair and assembly of the engine components Use only Genuine Onan replacement parts to ensure quality and the best possible repair and overhaul results When ordering parts always use the complete model and spec number as well as the serial number shown on the nameplate ENGINE MODEL REFERENCE Identify your model by referring to the model and specification spec letter as shown on the unit name plate Always use these numbers and the engine serial number when making reference to your engine How to interpret MODEL and SPEC NO 1 Factory code for general identification of basic engine series Cubic inch displacement Engine duty cycle Fuel required G gasoline Cooling system description A air cooling pressure BHP rating 7 Factory code for designated optional equipment if any 8 Specification spec letter which advances with factory production modifications 4 G o INCORRECT SERVICE OR REPLACEMENT OF PARTS CAN RESULT IN SEVERE PERSONAL INJURY AND OR EQUIPMENT DAMAGE SERVICE PERSONNEL MUST BE QUALIFIED TO PERFORM ELECTRICAL AND OR MECHANICAL SERVICE Redistribution or publication of this document by any means Is strictly prohibited Specifications This manual contains SI metric equivalents that follow immediately in parentheses after the U S customary units of measure UNIT OF SERIES SPECIFICATION MEASURE B43E B43G B
12. corrosion Poor contact at the battery cable connections is often a source of trouble Make sure battery cables are in good condition and that contacting surfaces are clean and tightly connected Do not reverse battery leads Use recommended battery tools when disconnecting leads to avoid mechanical battery damage A WARNING Ignition of explosive battery gases can result in severe personal injury Do not smoke or allow any ignition source near the battery SPECIFIC GRAVITY READING SHOULD BE 1 260 at 77 F 25 C FIGURE 5 SPECIFIC GRAVITY TEST BATTERY POST CABLE TERMINAL FIGURE 6 BATTERY CABLE CONNECTION 8 2 BATTERY JUMP STARTING Occasionally it may be necessary to jump start charge a weak battery using a charged booster battery to start your engine If jump starting is necessary the following procedure is recommended in order to prevent starter damage battery damage and personal injuries Overcranking the engine can cause ACAUTION starter damage Allow 5 minutes for starter to cool if engaged for longer than 30 seconds 1 Disconnect engine load 2 Use only a battery of the same voltage 12V as is used with your engine 3 Attach one end ofthe positive booster cable red to the positive terminal of the booster battery Attach the other end of the positive cable to the positive terminal of your engine battery 4 Attach one end of the negative booster cable black to negative termi
13. oil PRODUCE CROSS HAT CH SCRATCHES 10 12 Deglazing Cylinder Bores Deglazethe cylinder bores if there are no scuff marks and no wear or out of round beyond specifications before installing new rings Deglazing gives a fine finish but does not enlarge cylinder diameter so the original pistons with new rings may still be used The reason for deglazing a cylinder is to provide cavities to hold oil during piston ring break in 1 Wipe cylinder bores with a clean cloth which has been dipped in clean light engine oil Use a brush type deglazing tool with coated bristletips to produce a crosshatch pattern in the cylinder bore Use a slow speed drill to drive the deglazing tool Move deglazing tool up and down in cylinder 10 to 12 complete strokes rapidly enough to obtain a crosshatch pattern Figure 19 AVOID THIS FINISH FOR FAST RING SEATING FIGURE 19 CROSS HATCHING Improper cylinder cleaning will ACAUTION result in engine damage Do not use gasoline solvents or commercial cleaners to clean cylinder bores Clean cylinder bore thoroughly with soap water and clean rags Continue cleaning until a clean white rag shows discoloring when wiped through cylinder bore CRANKSHAFT Clean crankshaft thoroughly and inspect journals for scoring chipping cracking or signs of overheating If crankshaft has overheated is scored or excessively worn reconditioning or replacement will be required Examine
14. replacement of worn parts Carburetor repair parts are available General instructions for overhauling a carburetor are given below Carefully note the position of all parts while removing to assure correct placement when reassembling Read through all the instructions before beginning for a better understanding of the pro cedures involved Carburetor components are shown Figure 3 Ignition of fuel can result in severe A WARNING personal injury or death Do not smoke or allow any spark pilot light or arcing equip ment near the fuel system NEEDLE VALVE FIER MAIN JET amp ium d b O DLE ADJUSTMENT THROTTLE der ANS NEEDLE SHAFT lt a Z AND LEVER Pa CAP FS 1440 3 NIKKI CARBURETOR WITH SEMI AUTOMATIC CHOKE AND LIMITED IDLE MIXTURE SCREW CHOKE PLATE CHOKE SHAFT FLOAT 5 3 ASSEMBLY 1 SESS FUEL INLET VALVE THROTTLE SHAFT AND LEVER THROTTLE STOP ees SCREW Ge me IDLE ADJUSTMENT NEEDLE THROTTLE PLATE WALBRO CARBURETOR CHOKE PLATE p CHOKE SHAFT FLOAT ASSEMBLY i OPTIONAL MAIN FUEL ADJUSTMENT FIXED MAIN JET S AS oa FUEL 34 VALVE f IDLE ADJUSTMENT NEEDLE THROTTLE STOP SCREW 7 THROTTLE PLATE 1 FS 1440 NIKKI CARBURETOR FIGURE 3 CARBURETOR ASSEMBLY 1 3 Removal 1 2 3 Remove air cleaner and hose Disconnect governor and throttle linkage choke control and fu
15. 0 82 55 0 005 0 13 0 003 0 08 2 187 55 55 2 188 55 58 2 0015 50 84 2 0040 50 90 1 3760 34 95 1 3770 34 98 1 9992 50 78 2 0000 50 80 0 0025 0 064 0 0038 0 097 1 6252 41 28 1 6260 41 30 0 006 0 15 0 012 0 30 1 6280 41 35 1 6285 41 36 0 0020 0 051 0 0160 0 406 0 6879 17 47 0 6882 17 48 0 0020 0 051 0 0033 0 084 1 3740 34 90 1 8745 34 91 0 0015 0 038 0 0030 0 076 0 0030 0 076 0 300 7 62 0 258 6 55 0 0033 0 084 0 0053 0 135 0 68774 17 47 0 68814 17 48 0 080 2 032 0 081 2 057 0 080 2 032 0 081 2 057 0 188 4 775 0 189 4 801 DESCRIPTION PISTON PIN Clearance in Clearance in Connecting Rod ROG See ieee Soe ERU Ed en wate PISTON RINGS Clearance TOD s cats et ieee yea ved tae Ring End Gap in INTAKE VALVE Stem Diameter RO SIRE T E Poe RUE S pe Clearance Stem to Valve Face C ES INTAKE VALVE SEAT Seat Bore Diameter Seat Outside Diametr SCA Ta ERAT CREE Valve Seat Width Valve Seat Angle 9 6 9 S 9 9 S 1 B e 9 9 B R
16. 10 0 mm 0 213 5 41 NEEDLE BEND FLOAT ARM AND SEAT HERE TO ADJUST FLOAT LEVEL ADJUSTMENT WITH FUEL NO FUEL FLOAT DROP ADJUSTMENTS When checking float level and float drop measure to float body not seam FS 1689 NIKKI FLOAT LEVEL ADJUSTMENT BEND FLOAT ANO SEAT TANG HERE BEND FLOAT ARM TO ADJUST MINIMUM HERE TO ADJUST FUEL LEVEL FLOAT DROP 472 12 0 mm 0512 028 1 3 71 eer FLOAT LEVEL ADJUSTMENT WITH FUEL NO FUEL FLOAT DROP ADJUSTMENTS When checking float level and float drop measure to float body not seam NIKKI FLOAT LEVEL ADJUSTMENT WITH SEMI AUTOMATIC CHOKE AND LIMITED IDLE MIXTURE SCREW FIGURE 4 CARBURETOR FLOAT LEVEL ADJUSTMENTS 1 9 PULSATING DIAPHRAGM FUEL PUMP Pulsating diaphragm fuel pumps or pulse pumps rely on changes in crankcase vacuum to create a pulsating movement of the pump diaphragm As the engine s pistons move outward a vacuum is created This vacuum is transmitted to the pump diaphragm causing it to pull back and suck fuel into the pump As the engine s pistons move inward crankcase vacuum is reduced and the diaphragm return spring pushes the pump diaphragm forward forcing fuel through the pump outlet Fuel Pump Test Procedure Before testing make certain that fuel pump vacuum line connections are tight and free of leaks 1 Operate engine at an idle for five minutes to ensure that carburetor 1 full of fuel 2 Shut engine off and remo
17. 48G Number of Cylinders 2 2 2 Bore in 3 250 3 250 3 250 mm 82 55 82 55 82 55 Stroke in 2 620 2 620 2 875 mm 66 55 66 55 73 00 Displacement cu in 43 3 43 3 47 7 cm 710 710 782 Compression Ratio 6 2 to 1 6 5 to 1 7 0 to 1 Rated Speed Maximum RPM 3600 3600 3600 Power at BHP 16 18 20 Rated Speed KW 11 9 13 4 14 9 Cil Capacity Qts 1 5 1 5 1 5 Without Filter litre 1 4 1 4 1 4 Oil Filter Capacity Qts 3 3 litre 3 3 3 Crankshaft Rotation viewed from flywheel Clockwise Clockwise _ Clockwise Valve Clearance Cold Intake in 005 005 005 13 13 13 Exhaust in 013 013 013 mm 33 33 33 Spark Plug Gap in 025 025 025 mm 64 64 64 Breaker Point Gap Static SpecA amp B Full Separation and Engine Cold in 016 016 020 mm 41 41 53 Begin Spec C in 016 mm 41 Ignition Timing Spec A amp B BTC 16 16 20 Begin Spec C BTC 16 Cylinder Compression psi 75 to 115 75 to 115 75 to 115 kPa 517 to 793 517 to 793 517 to 793 2 1 Redistribution or publication of this document by any means is strictly prohibited Dimensions and Clearances All clearances given at room temperature of 70 F 21 C All dimensions in inches approximate millimetre dimensions in parentheses unless otherwise specified DESCRIPTION CYLINDER BLOCK Cylinder Bore Honed Maximum Allowable E E E obese ea beds OU
18. Adjust carburetor and governor according to directions given in this section Reassembly and Installation Nikki limited idle mixture 1 4 1 Install needle valve main jet and float assembly Make sure float pivot pin is properly placed and float moves freely without binding Turn carburetor on its side and measure float level Figure 4 Adjust float level only if necessary Measure float drop the distance from the top of carburetor body to top of float Adjust only if necessary Position gasket on lower carburetor section and install upper carburetor section Install idle adjustment screw throttle stop screw and fixed main jet plug Mount carburetor on intake manifold and install assembly on engine Mount air cleaner assembly Connect air intake hose breather hose fuel line vacuum line and throttle linkage Adjust carburetor and governor according to direc tions given this section BEND FLOAT TAB HERE 0 02 0 02 INCH TO ADJUST STRAIGHT FUEL LEVEL EDGE 0 25 INCH BEND FLOAT ARM MINIMUM HERE TO ADJUST FLOAT DROP 0 20 INCH CARBURETOR BODY O NEEDLE AND SEAT FLOAT LEVEL ADJUSTMENT WITH FUEL NO FUEL FLOAT DROP ADJUSTMENTS When checking float level and float drop measure to float body not seam FS 1524 WALBRO FLOAT LEVEL ADJUSTMENT BEND FLOAT 0 028 0 028 MINIMUM TANG HERE 0 712 0 712 mm FUEL LEVEL FLOAT DROP TO ADJUST 0 394
19. EAT GRINDING Some engines are equipped with a premium valve package aluminized intake valves If the aluminized valve face does not clean up using a wire brush the valve face may be refinished This removes the aluminized coating from the valve face An aluminized valve that has been refinished will normally have life expectancy equal to a standard valve If longer valve life is required worn or damaged valves should be replaced with new premium valves Before installing new valves or previously used valves inspect valve seats for proper valve seating If used valves are reinstalled the valve stems should be cleaned and valve faces ground to their specified angles of 44 Refinish valve seats to a 45 angle When refacing valves and seats remove all evidence of pitting and grooving If end of valve stem is pitted or worn true it and clean it up on the refacer wheel very light grind is usually enough to square stem and remove any pits or burrs The valve guide should be thoroughly cleaned If valve guide is worn or valve is warped the necessary parts must be replaced By grinding the valve face and seat at slightly different angles a fine line of contact on face and seat is obtained eliminating the need to lap the seating sur faces The one degree difference in angles is defined as the interference angle Figure 6 The seat angle is greater than that of the valve face This assures contact at the maximum diameter on valv
20. ENT 3 Manually pull the starter pinion gear outward on its shaft until pinion gear teeth mesh completely with Push prepared end of pigtail lead into hole in replace flywheel ring gear teeth Energize solenoid on ment brush from the smali chamfered side Solder pigtail solenoid shift starter lead to replacement brush on the large chamfered side using 50 50 tin lead rosin core solder and a standard 240 325 Watt soldering iron Use a file to remove any excess solder that may extend beyond brush surface ACAUTION Material protruding from soldered side surface of brush can cause equipment damage Do not use excessive solder or heat and file any excess material from brush surface I STARTER MOTOR Measure the amount of free travel lash between the pinion gear teeth and the ring gear teeth See Figure 12 If lash is too tight causing binding and slow starter operation or if lash is greater than 0 035 inch 0 889 lash must be adjusted FLYWHEEL RING GEAR 0 020 0 015 inch 0 51 0 38 mm STARTER GEAR FREE TRAVEL WHEN SY 3 ENGAGED WITH FLYWHEEL GEAR PINION GEAR ES 1003 FIGURE 12 CHECKING STARTER GEAR LASH To adjust iash on starters without slotted mounting holes remove starter Use a 21 64 inch 8 334 mm drill to enlarge one mounting hole in starter mounting bracket Install starter motor and adjust lash to 0 020 in 0 015 in 0 51 mm 0 38 mm Remove flywheel an
21. ETAILS GOVERNOR CUP With the gear cover removed the governor cup can be taken off after removing the snap ring from the camshaft center pin Catch the flyballs while sliding the cup off Figure 10 Replace with a new part any flyball which is grooved has a flat spot the ball spacer if its arms are worn or otherwise damaged the gear spacer assembly if loose on gear hub and the governor cup if the race surface is grooved or rough The governor cup must be a free spinning fit on the camshaft center pin but without any excessive play If replacing the ball spacer be sure to position it so an arm is lined up with the space on the camshaft gear if your camshaft gear does not have a space in it disregard this paragraph If the ball spacer arm is not lined up with the space in the camshaft gear a flyball can slip into the space and cause engine racing and governing problems Figure 10 When installing the governor cup tilt the engine so the gear is up put the flybalis in place Figure 10 and install the cup and snap ring on the center pin The camshaft center pin extends out 3 4 inch 19 mm from the end of the camshatt This distance provides an in and out travel distance of 7 32 inch 5 6 mm for the governor cup as illustrated Hold the cup against the flyballs when measuring The camshaft center 10 7 cannot be pulled outward or removed without damage Ifthe center pin extends outtoo far the cup will no
22. IHOSS300V 1VOIt LO3 13 ANY SNIHIM Q3 TT1V1SNI HAWOLSNDS sv 3115 ag LSNW ISNA Calk d SON IVNOILdO IWNOILdO HOLIMS HOLIMS OM ILVH Odol He F 109 HOLIMS NOILINDI NOILINS 1 SdINV HOLVNHWALLTV TIN LSNW HOLIMS NAAOGLNHS NO 35 vxV31 VIN SZ ALVNIWINS OL TWNOILd0 193NNODSIG NOLLO3NNOO AH3 LLVH 3SH3A3H 19039 934 S103 L0ud dW ASN OV OV S1108 ONILNNOW HONOYHL aa LSNW HOLVIND3SY INOILAVS 1VNOI LdO H3 L3IAINV lo GION31OS lHVvlS HdlHVlS e HOLIMS 1415 133H QNIH38 ENGINE WIRING DIAGRAM Solenoid Shift Type Starter HOLIMS 3dAL SAILONOLNY NI QOHNISINOO S3HOLIMS NOILIN I LYVLS ALON L Ze9gi Sa YASNSQNOO SLNIOd 9 el 5 5 A8 Q3HSINH YALYVLS CVNOILdO HOLIMS HOLIMS HOLIMS Odor 1495 Moor HOLIMS y o JWNOILdO JLON 335 HOLIMS 4 NMOGLNHS 39V3YV31 VIN L31VNIWIT3 OL WNOILdO ALlH V 1Od ASYSASY INOHH 19389 9348 LIOA SLO3 LOud dI NV 95 3 4 SL 108 SNILNDONW Q3GNf 1OHO 38 LSNW INOILAVD JLO3NNOOSIQ OV 8 OV S3IHOSS3202
23. OP A SCREW CARBURETOR THROTTLE PLATE GOVERNOR CONTROL LINKAGE GOVERNOR SPRING GOVERNOR GOVERNOR SHAFT YOKE PIVOT SIDE PULL GOVERNOR 3 Holding linkage and governor arm toward direc tion of carburetor insert end of linkage into which ever hole in governor arm lines up the closest If between two holes insert in next hole out On side pull governors the governor spring is set by the factory in the third hole of the governor arm Third hole from pivot On front pull governors the governor spring is set by the factory in the second hole of the governor arm adapter Second hole from pivot To increase sensitivity move spring loop into a hole closer to the pivot To decrease sensitivity move spring loop into a hole farther away from the pivot After sensitivity has been set recheck the low speed rpm setting Adjust if necessary THROTTLE STOP SCREW Un d CARBURETOR THROTTLE PLATE A GOVERNOR CONTROL LINKAGE GOVERNOR ARM V 6 9 gt ADAPTER PIVOT iY GOVERNOR ARM a GOVERNOR SHAFT YOKE GOVERNOR SPRING FRONT PULL GOVERNOR FIGURE 8 VARIABLE SPEED GOVERNOR ADJUSTMENTS Redistribution or publication of this document by any means is strictly prohibited Ignition and Battery Charging IGNITION SYSTEM DESCRIPTION The engine is equipped with an automotive type battery ignition system Both sp
24. RO ROUNG o RR Main Bearing Inside Diameter Without bearing Main Bearing Inside Diameter Installed Camshaft Bearing Bore Bearing installed CRANKSHAFT Main Bearing Journal Main Bearing Clearance sas Connecting Rod Journal Crankshatt Enid Play EA CONNECTING ROD Large Bore Diameter Rod bolts properly torqued Connecting Rod Side Piston Pin Bushing Bore Finished bore Bearing to Crankshaft Clearance Aluminum ROG eee oes CAMSHAFT Bearing Journal 1 Bearing Clearanbto canto tt ts TR End Camshaft Lift orientate ere nd PISTON Clearance in Cylinder Measure 90 to pin 1 187 inch below top of piston Piston PIN eee RN eee eee Ring Groove Width Top Compression No 2 Compression Nod OI GODtTOL RING aso i cacti MINIMUM MAXIMUM Inches mm Inches mm 3 2490 82 53 3 250
25. Thoroughly clean filter mounting surface and install new element making sure new gasket is inserted in the element Apply a thin film of oil to the gasket Spin element down by hand until gasket just touches mounting pad and then turn down an additional 1 2 3 4 turn Do not overtighten With oil in crankcase start engine and check for leaks around filter element Retighten only as much as necessary to eliminate leaks do not overtighten CRANKCASE BREATHER Refer to Periodic Maintenance Schedule located in the Operator s Manual for crankcase breather service interval Service sooner if crankcase becomes pres surized as evidenced by oil leaks at the seals or excessive oil in the air cleaner housing Most parts cleaning solvents are AWARNING flammable and can cause severe personal injury or death if used improperly Follow the manufacturer s recommendations when cleaning parts Remove the breather tube from the valve cover Figure 3 Remove the pack capscrew flatwasher valve cover and gasket spring flatwasher reed valve and breather baffle Discard gasket and clean all parts in parts cleaning solvent ACAUTION Overtightening the valve cover can cause engine damage Do not over tighten valve cover The reed valve must be flat with no sign of a crease Assemble using a new gasket Torque capscrew to 1 2 ft lbs 1 3 Nm 6 2 BREATHER TUBE PLASTIC TIE HEX HEAD CAPSCREW FLAT WASHER m
26. V ANY SHAWOLSNO 301 13215 3515 0c SI 3011 133HM ONIH38 Starting System ELECTRIC STARTER Normally the starter will require little or no service other than possible brush replacement However if through accident or misuse the starter requires service or overhaul the following information will provide the information necessary to perform this service Service When starting engine note starter motor action The pinion gear should mesh quickly with flywheel ring gear and spin engine Once engine starts and solenoid opens the starter should disengage and stop If starter cranks engine slow or not at all check start circuit components Failure to crank 1 normally caused by low battery charge defective battery cables corroded or poor connections or low temperatures If after checking these variables starter continues to crank slowly starter must be removed and repaired Starter Removal AWARNING Accidenial starting of the engine can result in severe personal injury or death Disconnect the negative battery cable and spark plug wires while servicing engine controls or asso ciated equipment SEAL THROUGH BOLT DUST COVER ea PINION GEAR PUT STUD 1 Remove both battery cables from battery Discon nect ground cable first 2 Disconnect battery and electrical lead wires from starter 3 Re
27. acer anti drift spring stop nut washer and stop nut Push dust cover on until it snaps into position SOLENOID FRONT BRACKET RETAINER SCREW CLUTCH STOPPER RETAINING RING BUSHING SEAL Starter Disassembly Solenoid Shift Type 1 ADJUSTMENT OVERRUNNING WASHERS ASSEMBLY ARMATURE Remove terminal nut and wire lead from solenoid Figure 2 Remove the two solenoid mounting screws and remove solenoid Scribe a mark across frame and rear bracket to aid assembly Remove the two through bolts Remove rear bracket and frame assembly Carefully remove armature and lever from front bracket Note direction of lever and retainer Remove the two brush mounting screws and remove the rear bracket Remove brush holder assembly from the frame by pulling the brushes out THROUGH BOLT SPRING BUSHING REAR BRACKET BRUSH HOLDER ASSEMBLY BRUSH ES 1665 FIGURE 2 STARTER MOTOR SOLENOID SHIFT TYPE 8 Push stopper toward pinion and remove snap ring Figure 3 9 Remove stopper and overrunning clutch from armature shaft ES 1622 FIGURE 3 REMOVING OVERRUNNING CLUTCH 10 Inspect starter for damaged or worn parts 11 Repair or replace all damaged or worn parts as needed Starter Assembly Solenoid Shift Type 1 Install seal in nose housing Install overrunning clutch on the armature shaft Slide s
28. ark plugs fire simultaneously thus the need for a distributor is eliminated IGNITION TIMING The timing is preset at the factory Slight timing changes can be made by adjusting the point gap BREAKER POINTS The timing is adjusted to specification during initial engine assembly and is fixed by the point gap adjust ment To maintain maximum engine efficiency change the breaker points as recommended in the Periodic Maintenance Schedule Replacement and Adjustment 2 eo 9 Remove spark plugs Remove breaker box cover Rotate crankshaft clock wise facing flywheel until points are fully open Remove condenser screw A and detach condenser lead and coil lead screw B Engines with con densers mounted on the air cleaner bracket do not need to be removed unless being replaced Remove two Allen screws C and lift breaker assembly from engine Replace condenser and point assembly with new parts and reinstall using above procedure in reverse order of removal Adjust point gap by rotating crankshaft clockwise facing flywheel by hand until the points are fully open Set the point gap using flat feeler gauge to gap specified in SPECIFICATIONS by adjusting the Allen screw D inward or outward Figure 1 016 point gap is equivalentto 16 BTC 020 inch point gap is equivalent to 20 BTC Make sure feeler gauge is clean and free of any grease oil or dirt POINT GAP E FC
29. bution or publication of this document by any means is strictly prohibited General Information INTRODUCTION This manual deals with specific mechanical and elec trical information needed by engine mechanics for troubleshooting servicing repairing or overhauling the engine Use the separate PARTS MANUAL for parts identification and for establishing their proper location on assemblies The PARTS MANUAL contains detailed exploded views of each assembly and the individual piece part numbers and their proper names for ordering replacement parts The illustrations and procedures presented in each section apply to the engines listed on the cover The flywheel blower end of the engine is the front end so right and left sides are determined by viewing the engine from the front The No 1 cylinder is on the left No 2 cylinder is on the right If a major repair or an overhaul is necessary a competent mechanic should either do the job or supervise and check the work of the mechanic assigned to the job to ensure that all dimensions clearances and torque values are within the specified tolerances Use the table of contents for a quick reference to the separate engine system sections The troubleshooting guide is provided as a quick reference for locating and correcting engine trouble The wiring diagram shows how the electrical compo nents are interconnected The disassembly section contains major overhaul procedures for step
30. cause pre ignition and pinging Refinish valves thatare slightly pitted or burned accurate valve grinder If valves are badly pitted or have a thin margin when refacing replace them VT 1020 FIGURE 2 VALVE STEM AND VALVE GUIDE INSPECTION Stems And Guides Always check valve stems and guides for wear as shown in Figure 2 Use a hole gauge to measure the valve guide When clearance with stem exceeds original clearance by that specified in DIM ENSIONS AND CLEARANCES replace either valve or guide or both as may be necessary Always regrind seat to make concentric with the newly installed guide Worn valve stem guides can be replaced from inside the valve chamber a seal is provided behind the intake valve guides only The smaller diameter of the tapered valve guides mustface toward the valve head Tappetsare also replaceable from the valve chamber after first removing the valve assemblies Valve Guide Removal Before removing valve guides use an electric drill with a wire brush to remove carbon and other foreign material from top surface of guides Failure to perform this operation may resultin damage to the guide bores Drive the guides out with a hammer and valve guide driver 10 3 Driving out old valve guides can cause A CAUTION guide and tappet bore damage Do not strike guide or tappet bores with driver during removal Valve Guide installation Run a small polishing rod covered with crocus cloth through valve
31. cury High Idle 2 6 inches 1 7 psi of mercury Fuel Pump Repair This section applies only to Facet fuel pump The Nikki fuel pump is not repairable replace unit if test readings are not within the values specified in Table 1 1 Remove the vacuum and fuel lines Inspect the lines for wear cracking or brittleness Replace as necessary 2 To insure correct alignment when reassembling scribe a line across the outer pump parts on each end of the pump 3 Holding the pump carefully remove the assembly screws Figure 5 4 Carefully pull apart the pump sections and check for worn or damaged parts Install pump repair kit 5 Check and unclog if necessary the small diaphragm air bleed hole located behind the pump diaphragm in the pump base ACAUTION A clogged diaphragm air bleed hole can cause diaphragm wear and seal damage Be sure air bleed hole is unclogged 6 Replace gaskets and reassemble pump Reinstall assembly screws checking the scribe marks for proper alignment Reinstall fuel and vacuum lines and clamps Improper fuel pump parts align AWARNING ment or misconnected fuel lines can result in leaking fuel creating a serious fire hazard Use extreme care when reassembling and reinstalling fuel pump PUMP COVER GASKET ASSEMBLY SCREWS FIGURE 5 AIR CLEANER ACAUTION A dirty air cleaner element can cause engine damage Ensure air cleaner element is kept clean and free of excess debris Eng
32. d torque starter mounting capscrews to 24 to 26 ft lbs 33 to 35 Nm Use Onan flangehead capscrews or SAE grade 8 capscrews with a hardened flatwasher Do not use lockwashers Failure to torque starter bolts ACAUTION properly can cause starter failure and ring gear damage Torque starter bolts to correct values when installing Install flywheel spark plugs blower housing and cylinder air housings For correct cylinder air housing installation required on some models refer to Cylinder Air Housing Clearance Connect battery cable and wires to starter Connect battery cables to battery Connect ground cable last To install starter on B43E Beginning Spec B43G Beginning Spec C and B48G Beginning Spec E engines use the following procedure On these engines starter pinion gear lash does not require adjustment 1 Install starter motor and torque mounting capscrews to 24 to 26 ft Ibs 33 to 35 Nm 2 Install flywheel blower housing and cylinder air housings For correct cylinder air housing instal lations required on some models refer to Cylinder Air Housing Clearance 3 Connectbattery cable and wires to starter Connect battery cables to battery Connect ground cable last Redistribution or publication of this document by any means is strictly prohibited Engine Disassembly DISASSEMBLY ASSEMBLY When complete engine disassembly is necessary first remove all complete assemblies Individual as
33. e caution when close to hot exhausts moving parts etc Protect Against Moving Parts Donotwear loose clothing in the vicinity of moving parts such as PTO shafts flywheels blowers couplings fans belts etc Keep your hands away from moving parts Batteries Before starting work on the engine disconnect batteries to prevent inadvertent starting of the engine e DO NOT SMOKE while servicing batteries Lead acid batteries give off a highly explosive hydrogen gas which can be ignited by flame electrical arcing or by smoking Verify battery polarity before connecting battery cables Connect negative cabie last Fuel System DO NOT fill fuel tanks while engine is running e DONOT smoke or use an open flame in the vicinity of the engine or fuel tank Internal combustion engine fuels are highly flammable Fuel lines must be of steel piping adequately secured and free from leaks Piping at the engine should be approved flexible line Do not use copper piping for flexible lines as copper will work harden and become brittle enough to break Be sure all fuel supplies have a positive shutoff valve Exhaust System Exhaust products of any internal combustion engine are toxic and can cause injury or death if inhaled All engine applications especially those within a confined area should be equipped with an exhaust system to discharge gases to the outside atmosphere e Do not use exhaust gases to
34. e ground with a 45 degree stone and the width of the seat band should be 1 32 inch to 3 64 inch 0 79 to 1 2 mm wide Grind only enough to assure proper seating Place each valve in its proper location Check each valve for a tight seat Make several marks at regular intervals across the valve face using machinist s bluing Observe if the marks rub off uniformly when the valve is rotated part of a turn against the seat The valve seat should contact the valve face evenly at all points The line of contact should be at the center of the valve face FLYWHEEL Removing the flywheel is a relatively simple process but the following procedure must be followed to avoid damage to the gear case and possible injury to the operator 1 Turn the flywheel mounting screw outward about two turns Incorrect flywheel removal can AWARNING e result in severe personal injury Do not remove flywheel screw completely when using flywheel puller 2 install a puller bar on the flywheel as shown in Figure 8 FLYWHEEL FLYWHEEL PULLER FLYWHEEL MOUNTING SCREW CS 1000 FIGURE 8 BLOWER WHEEL PULLEY 3 Turn the puller bar bolts in alternately until the wheel snaps loose on the shaft ACAUTION Improper flywheel removal cause gear case damage Do not use any tools to pry against gear cover when removing flywheel 4 Unscrew the puller from the flywheel remove the flywheel mounting screw and washer and pull the
35. e installing the front main bearing use the towelette included with the bearing kit to clean the outside of the bearing and bearing bore in the block Breathing vapor from towelette and AWARNING prolonged contact with skin can be harmful Use only in well ventilated area and avoid prolonged contact with skin After allowing three to four minutes for drying apply the Locktite from the small tube to the mating surfaces of the bearing and the bearing bore Align the oil holes in the bearing with the oil holes in the bearing bore Fig ure 22 The oil passage should be at least half open Install the bearing flush with the block using the combi nation driver Wipe off any exesss Locktite around the bearing Allow at least one hour for hardening at room temperature REAR BEARING END PLATE LOCK PIN ALIGN BEARING OIL HOLES WITH OIL HOLES IN BEARING BORE THRUST WASHER SHIM FIGURE 21 BEARINGS FOR REAR BEARING PLATE Engines shipped from the factory have separate thrust washers and main bearings for both front and rear of engine Front bearing replacement part is a one piece bearing with attached thrust washer as shown in Figure 22 Do notadd an additional thrust washer to this _ front bearing FRONT MAIN BEARING BORE ALIGN BEARING NOTCHES WITH LOCK PINS AND MATCH OIL HOLES B49 Rev REPLACEMENT FRONT MAIN BEARING FIGURE 22 FRONT BEARING INSTALLATION In the rear bearing plate install the bearing flush t
36. e seat seating surface VT 1021 FIGURE 6 VALVE INTERFERENCE ANGLE Refinish valve faces to a 44 angle on a valve refacing machine The first cut from valve face must be a light grinding Check if there is an unevenness of metal being removed only part of valve s face has been touched check to see if valve is properly seated in machine or if valve is warped worn or distorted When cut is even around the whole valve face keep grinding until com plete face is ground clean Be sure the correct valve face angle is maintained When valve head is warped a knife edge will be ground Figure 7 on part or all of the head due to the large amount of metal that must be removed to completely reface valve Heavy valve heads are required for strength and good heat dissipation Knife edges lead to breakage burning and pre ignition due to heat localizing on the edge Replace any valve that cannot be entirely refaced while keeping a good valve margin Figure 7 or is warped worn or damaged in any way The amount of grinding necessary to true a valve indicates whether valve head is worn or warped WARPED VALVE WITH KNIFE EDGE KNIFE EDGE UC GC d 1 16 INCH 1 6 mm MINIMUM GOOD MARGIN 1184 FIGURE 7 VALVE HEAD MARGIN When new valve seats are installed or previously used seats reground refinishing must be done witha valve seat grinder used according to the manufac turer s directions Valve seats should b
37. eck the battery for serviceability Keep these points in mind when testing or servicing the flywheel alternator 1 Be sure engine is being run long enough and fast enough to recharge battery after each start Charging system tests require a full charged battery Alternator output is reduced in direct proportion to engine rpm Also power required for accessories reduces power available to recharge battery MOUNTED ON CYLINDER COVER N VR1 MOUNTED BEHIND BLOWER WHEEL ALT STATOR AC AC TO BATTERY CAUTION REGULATOR MUST BE GROUNDED THROUGH MOUNTING BOLTS ES 1332 FIGURE 7 FLYWHEEL ALTERNATOR SYSTEM 2 Theregulator rectifier has builtin protection against open circuits or short circuits on the alternator output B terminal Either condition will cause the regulator rectifier to shut off and appear as ifitis not functioning Prior to checking the regulator rectifier check all wiring between the regulator rectifier B terminal and the battery positive terminal to assure it is free of open circuits resistances or short circuits Also ifthe battery is extremely discharged it may have insufficient power to turn on the regulator rectifier Be sure regulator rectifier plug connector is inserted properly Plug must bottom in receptacle this eliminates any resistance due to a poor ALTERNATOR OUTPUT TEST Use a volt ohmmeter such as the Simpson 270 when testing the chargin
38. ection When rebuilding the engine thoroughly inspect block for any condition that would make it unfit for further use This inspection must be made after al parts have been removed and block has been thoroughly cleaned and dried 1 athorough check for cracks Minute cracks may be detected by coating the suspected area with a mixture of 25 percent kerosene and 75 percent light motor oil Wipe the part dry and immediately apply a coating of zinc oxide white lead dissolved in wood alcohol If cracks are present the white coating will become discolored at the defective area Always replace a cracked cylinder block 2 Inspect all machined surfaces and threaded holes Carefully remove any nicks or burrs from ma chined surfaces Clean out tapped holes and clean up any damaged threads 3 Check top of block for flatness with a straight edge and a feeler gauge Cylinder Bore Inspection Inspect cylinder bores for scuffing scratches wear and scoring If cylinder bores are scuffed scratched scored or worn they must be rebored and honed for the next oversize piston When the appearance of cylinder bores is good and there are no scuff marks check cylinder bore for wear or out of roundness as follows 1 Check cylinder bore for taper out of round and wear with a cylinder bore gauge telescope gauge or inside micrometer These measurements should be taken at four places top and bottom of piston ring travel parallel a
39. edure Tighten all bolts to 5 ft lbs 7 Nm then 10 ft lbs 14 Nm then to the torque specified in ASSEM BLY TORQUES Recheck all head bolts for correct torque B Asbestos head gasket torque procedure Tighten all bolts 5 ft lbs 7 Nm then 10 ft lbs 14 Nm then to the torque specified in ASSEM BLY TORQUES Recheck all head bolts for correct torque ALIGNING BLOWER WHEEL VENTURI AND CHAFF SCREEN It may be difficult to line up the screw holes in the blower housing chaff screen with those in the venturi and those in the blower wheel if these parts are separated without noting their relative positions The holes will match up if the paris are aligned as shown in Figure 29 SCREW HOLES ALIGN THROUGH PART DIAMETER 9 BLOWER WHEEL SCREW HOLES ALIGN THROUGH PART DIAMETER VENTURI SCREW HOLES ALIGN THROUGH PART DIAMETER CHAFF SCREEN a POSITION PARTS WITH ALIGNED SCREW HOLES AT TOP CS 1008 FIGURE 29 BLOWER WHEEL VENTURI AND CHAFF SCREEN ALIGNMENT CYLINDER AIR HOUSING CLEARANCE To adjust cylinder air housing clearance loosen 7 Figure 30 Insert spacer tool a On all B48G beginning Spec D B43G and 4 piece of 0 250 inch 6 35 mm thick bar stock will work engines the cylinder air housing to cylinder head between the cylinder head cooling fins and cylinder air cooling fin clearance must be checked during assembly housing at the points illustrated in F
40. el line from carburetor Remove the four intake manifold cap screws and lift complete manifold assembly from engine Remove carburetor from intake manifold Disassembly Walbro and Nikki 1 2 3 Remove throttle and choke plate retaining screws then plates Pull out throttle and choke shafts Remove main jet and idle adjustment needle Remove attaching screws and separate upper and lower carburetor sections Carefully note position of float assembly parts then pull out retaining pin and float assembly Remove needle and unscrew needle valve seat Disassembly Nikki limited idle mixture 1 2 3 Remove main jet and idle adjustment needle Remove attaching screws and separate upper and lower carburetor sections Carefully note position of float assembly parts then pull out retaining pin and float assembly Remove needle valve Cleaning and Repair ihe Soak all metal components not replaced in car buretor cleaner Do not soak non metal floats or other non metal parts Follow the cleaning manufacturer s recommendations Clean all carbon from the carburetor bore especially where the throttle and choke plates seat Be careful not to plug the idle or main fuel ports Dry outall passages with low pressure air 35 PSI Avoid using wire or other objects for cleaning that may increase the size of critical passages Check the condition of adjustment needle Replace if damaged R
41. eplace float if loaded with fuel or damaged Gheck the choke and throttle shafts for excessive play in their bore This condition may necessitate replacement of the carburetor Replace old components with new parts Reassembly and Installation Walbro and Nikki 1 Install needle valve and seat main jet and float assembly Make sure that float pivot pin is properly placed and that the float moves freely without binding Gently push float tang down until needle just seats measure float level as shown in Figure 4 Adjust float level if necessary Release float tang and measure float drop as shown in Figure 4 the distance from top of carburetor body to top of float Position gasket on lower carburetor section and install upper carburetor section Slide in throttle shaft and install plate using new screws Beforetightening the screws the plate must be centered in the bore To do so back off the throttle stop screw as necessary and completely close the throttle lever Seat the plate by tapping with a small screwdriver then tighten screws Install the choke shaft and plate in the same manner Install idle adjustment screw throttle stop screw and fixed main jet plug or optional main fuel adjustment needle Mount carburetor on intake manifold and install assembly on engine Mount air cleaner assembly Connect air intake hose breather hose fuel line vacuum line and throttle linkage
42. expansion of the ring Compression rings have a dot or the word top on one side of the ring to indicate which side faces the top of the piston Unmarked piston rings can be installed either way The oil control ring has an expander install the expander first and then close until the expander ends butt The joint should be 180 degrees from the gap of that ring FIGURE 26 PISTON RINGS INSTALLATION OF PISTON IN CYLINDER 1 Turn the crankshaft to position the number one rod bearing journal at the bottom of its stroke Lubricate the number one piston assembly and inside of the cylinder Compress the rings with a ring compressor Figure 27 Position the piston and rod assembly in the cylinder block Notched side of connecting rod must face camshaft Rod bolts must be off set toward outside of block Tap the piston down into the bore with the handle end of a hammer until the connecting rod is seated on the journal Figure 27 Install the bearing cap on the rod Install one fastener and tighten to 5 ft lbs 7 Nm Repeat this for the other fastener Tighten both fasteners down to 14 ft lbs 19 Nm CT 1047 10 16 NOTCH TOWARD CAMSHAFT CT 1048 Tuo SUT INSTALLING PISTON AND CONNECTING ROD FIGURE 27 Install the remaining piston and rod in the same manner Crank the engine over by hand to see that all bearings are free Install the base with a new gasket Install the cy
43. f resistance is not as specified replace stator If stator resistance readings are as specified and windings are not shorted to ground low AC voltage may be due to loss of magnetism If so blower wheel assembly must be replaced Check for magnetism with steel tool blade Next connect one ohmmeter test lead to stator wire connect the other test lead to ground If the ohmmeter reading is low the stator is grounded and must be replaced With the engine between 1800 to 2600 rpm observe the panel ammeter if not already equipped connect a test ammeter If no charging is evident proceed with the Alternator Output Test TABLE 1 TESTING 15 AND 20 AMPERE SYSTEMS TEST VALUES PROCEDURE 15A SYSTEM 20A SYSTEM Battery Voltage unit not running 13 6 to 14 7 VDC 13 6 to 14 7 VDC 0 1 to 0 2 Ohms 0 3 to 0 5 Ohms 31 VAC Minimum 51 VAC Maximum BASIC TEST 1 Battery Battery Voltage after unit is running 3 to 5 minutes 2 Regulator 3 Alternator Stator and Wiring Ohmmeter reading from stator output unit not running Check at plug 4 Alternator and Wiring Measure AC open circuit stator voltage with unit running Measure between two stator leads with plug disconnected and unit running at approximately 3600 rpm 40 VAC Minimum 60 VAC Maximum 84 ENGINE WIRING DIAGRAM Inertia Type Starter L L 9L S3 YAWOLSNO AG G3SHSINYNG S3
44. flywheel off the shaft Take care not to drop the wheel A bent or broken fin will destroy the balance Always use a steel key for mounting the flywheel GEAR COVER After removing the mounting screws tap the gear cover gently with a soft faced hammer to loosen it Figure 9 When installing the gear cover make sure that the pin in the gear cover engages the nylon lined smooth hole in the governor cup Turn the governor cup so that the nylon lined hole is at the three o clock position Use a small amount of grease to assist in holding governor cup in position The smooth side of the governor yoke must ride against the governor cup Turn the governor arm and shaft clockwise as far as possible and hold in this position until the gear cover is installed flush against the crankcase Be careful not to damage the gear cover oil seal ROLL PIN GOVERNOR SHAFT ROTATE GOVERNOR CUP SO THAT ROLL PIN FITS INTO THE METAL LINED HOLE OR PLASTIC BUSHING IN THE CUP GOVERNOR SHAFT YOKE Smocth Side Toward Cup IF FEELER WILL ENTER HOLE 172 BALL HAS FALLEN OUT FIGURE 9 GEAR COVER ASSEMBLY WHEN GOVERNOR 15 PROPERLY ASSEMBLED THE DIMENSION SHOWN ON DRAWING WILL BE AS INDICATED CAMSHAFT SNAP RING GOVERNOR CUP GOVERNOR FLYBALL 5 BALL GOVERNOR WRONG C 1107 INSTALLATION OF BALL SPACER 8 BALL GOVERNOR 6 BALL GOVERNOR FLYBALL LOCATIONS CS 1238 FIGURE 10 GOVERNOR CUP D
45. g system 1 With the engine running check the battery terminal voltage regulator output using a DC voltmeter Voltage outputshould be within the values specified in Table 1 voltage is greater than specified replace regulator rectifier assembly If voltage is less than specified proceed to step 2 Examineall wires for loose corroded broken connec tions short circuits etc Check fuses Repair as needed to assure complete circuits from regulator connection Keep clean and tight rectifier B terminal to battery positive terminal and from battery negative terminal to regulator rectifier case If battery voltage remains low with engine running proceed to step 3 4 Make sure alternator stator leads are not shorted together 5 Be sure regulator rectifier has a good ground 3 connection Mating surface for mounting must be clean and fastener tightened properly Disconnect plug from regulator rectifier and test the AC voltage at the plug with engine running near 3600 rpm If AC voltage reads more or less than specified in Table 1 proceed to step 4 If AC voltage is as specified but DC voltage is low replace regulator rectifier 6 Never reverse the battery leads 4 Use the Rx1 scale on the ohmmeter for detecting opens in the stator unit not running Disconnect plug from regulator rectifier Connect ohmmeter test leads to wires coming from stator Refer to Table 1 for resistance specifications I
46. gap accordingly IGNITION COIL To test primary and secondary windings within the ignition coil proceed as follows 1 Use a Simpson 260 VOM or equivalent 2 Place black lead on ground terminal of coil and red lead to positive terminal Primary resistance should read 3 87 4 73 ohms 3 Change resistance setting on ohmmeter Place ohmmeter leads inside of spark plug cable holes Figure 3 Secondary resistance should read 12 600 15 400 ohms 4 If any of the above conditions are not met replace coil Refer to PARTS CATALOG for correct part number OHMMETER Dad i FIGURE 3 COIL TEST SPARK PLUGS Check and regap spark plugs as recommended in the Periodic Maintenance Schedule located in Operator s Manual Replace spark plugs that show signs of fouling or electrode erosion FIGURE 4 SPARK PLUG GAP BATTERY INSPECTION Check battery cells with a hydrometer The specific gravity reading should be approximately 1 260 at 77 F 25 C Figure 5 if one or more Cells are low on water add distilled water and recharge Keep the battery case clean and dry An accumulation of moisture will lead to a more rapid discharge and battery failure Keep the battery terminals clean and tight Push the cable terminal down flush with or slightly below the top of the battery post Figure 6 After making connections coat the terminals with a light application of petroleum jelly or grease to retard
47. gs If either the front or rear bushing show signs of wear or damage replace them Bushing and rear bracket are replaced as an assembly Check armature shaft thrust gap if rear bracket is replaced Remove front bushing by tapping bushing from inside with a 7 16 inch tap Do not remove cap from front bracket Thread capscrew same size as tap into bushing Using a slide hammer remove bushing from front bracket Press new bushing into front bracket Use care not to distort inside diameter of bushing Brush Replacement Cut old positive brush from pigtail Starter Mounting at the brush Be careful not to damage field coil Clean 1 4 to 3 8 inch 6 5 to 9 5 mm of brush end of pigtail Before installing starter motor make sure the starter with sandpaper or emery cloth Figure 11 mounting surface on the engine base is clean and free of oil PIGTAIL LLL LLLI To install starter on B43G Prior to Spec C and B48G STILL ATTACHED gt lt CLEAN Prior to Spec E engines use the following procedure TO FIELD COIL approx 1 4 to 3 8 inch On these engines starter pinion gear lash requires adjustment and must be checked when starter is installed 7 lt SOLDER MUST NOT BA 1 Install starter motor and tighten mounting capscrews just enough to hold starter in place REPLACEMENT BRUSH SMALL CHAMFER 2 Remove spark plugs from the engine This allows free movement of the flywheel FIGURE 11 BRUSH REPLACEM
48. guide holes to clean out carbon and other foreign materials Place a new gasket on the intake valve guide and coatthe outer edge of each new guide with oil Place guide notch up in cylinder block and press in until guide stops or protrudes 11 32 inch 8 7 mm from rocker box side of block A suggested method of installation is shown in Figure 3 5 16 18 HEX NUT 2 REQUIRED 178 ZA T 5 16 FLAT WASHER 2 REQUIRED 32 mm 1 1 4 4 3 4 NE 5 16 18 THREADED ROD 2 3 8 60 mm 5 8 16 mm VT 1023 FIGURE 3 VALVE GUIDE INSTALLATION Valve Stem Seals Do not reuse vaive stem seals Each time the valves are removed from cylinder block a new seal must be used when valve is reinstalled Removing a valve after installing valve ACAUTION stem seal can cause seal damage Do not allow valve stem groove to come in contact with valve stem seal after installation Valve Spring Check valve springs for cracks worn ends distortion and tension If spring ends are worn check valve spring retainer for wear Check for spring distortion by placing spring on a fiat surface nextto a square Measure height of spring and rotate it against square edge to measure distortion If distortion exceeds 0 06 inch 1 5 mm replace spring Check spring tension at the installed height for both the valve open and closed position using an accurate valve spring tester Replace any valve spring that is weak cracked worn
49. heat a compartment Make sure that your exhaust system is free of leaks Ensure that exhaust manifoids are secure and are not warped by bolts unevenly torqued Exhaust Gas is Deadly Exhaust gases contain carbon monoxide a poisonous gas that can cause unconsciousness and death It is an odorless and coloriess gas formed during combustion of hydrocarbon fuels Symptoms of carbon monoxide poisoning are Vomiting Muscular Twitching Throbbing in Temples Dizziness Headache Weakness and Sleepiness If you experience any of these symptoms get out into fresh air immediately shut down the unit and do not use until it has been inspected The best protection against carbon monoxide inhalation is proper installation and regular frequent inspections of the complete exhaust system If you notice a change in the sound or appearance of exhaust system shut the unit down immediately and have it inspected and repaired at once by a competent mechanic Cooling System Coolants under pressure have higher boiling point than water DO NOT open a radiator pressure cap when coolant temperature is above 212 F 100 C or while engine is running Keep the Unit and Surrounding Area Clean Make sure that oily rags are notleft on or near the engine Remove all unnecessary grease and oil from the unit Accumulated grease and oil can cause overheating and subsequent engine damage and present a potentia fire hazard
50. igure 30 Tighten The correct clearance is 0 187 to 0 313 inch 4 76 to capscrews A and B and remove the spacer tool 7 94 mm Ls i Fj PSCREW A CAPSCREW A 187 to 313 inch 4 76 to 7 94 mm 187 to 313 inch 8 INCH 8 INCH 187 to 313 inch 203mm 4 7610 7 94 mm 7 if 4 76 to 7 94 mm 203 mm 6 INCH oe aa 152 mm CAPSCREW B CAPSCREW B HER 187 to 313 inch 4 76 to 7 94 mm M 1403 FIGURE 30 CYLINDER AIR HOUSING CLEARANCE 10 18 Redistribution or publication of this document by any means is strictly prohibited Onon Cummins Power Generation 1400 73rd Avenue N E Minneapolis MN 55432 763 574 5000 Fax 763 574 8087 Cummins and Onan are registered trademarks of Cummins Inc
51. ill stay where it is set A 9 16 inch 14 mm open end wrench is required to hold the tappet while turning the adjusting screw 7 To adjust valves on the right hand cylinder turn engine one complete revolution and again line up mark on the flywheel and the T C mark on the gear cover Then follow adjustment procedure given for left hand cylinder 8 Replace all parts removed in Step 2 Tighten all screws securely Torque manifold bolts to spec ified torque NOTE USEASTANDARD AUTOMOTIVE TYPE WRENCH TO ADJUST THE TAPPETS ev i VALVE SEAT VALVE SPRING lt INSERT VALVE GUIDE ONLY FIGURE 1 10 2 VALVE CLEARANCE VALVE RETAINER INTAKE VALVE VALVE ASSEMBLY VALVE SYSTEM A properly functioning valve system is essential for good engine performance All engines utilize an L head type valve design as shown in Figure 1 Access to the valve system can be obtained by removing the cylinder heads and the valve covers on top ofthe engine A valve spring compressor must be used to remove valves from the cylinder block A valve stem seal is used on the intake valve guides of some engines This seal mustbe replaced each time the valve is removed Piace valves springs retainers and tappets in a rack as they are removed from cylinder block so they can be identified and reinstalled in their original locations Discard old valve stem seals a
52. imited idle adjustment range between stops of 1 8 turn The screw should only be adjusted within these limits in to lean the mixture out to richen There is no main mixture adjustment When replacing the idle mixture screw turn until lightly seated then turn back idle mixture screw out 1 1 4 turn Replace the limiter cap with the plastic stop approximately centered LOW SPEED STOP HIGH SPEED NFA STOP 1396 FRONT PULL GOVERNOR ASSEMBLY FIGURE 1 GOVERNOR SPEED ADJUSTMENT 2 Start the engine and allow it to warm tho roughly at least 10 minutes some equipment manufacturers may require higher throttle stop speed and governor low speed rpm Settings Refer to equipment manufac turer s Operators Manual for the correct rpm set tings When rpm settings are not specified by the equipment manufacturer use the rpm settings listed in Steps 3 amp 5 Go Move the engine speed control to the slow posi tion Bend or turn the low speed stop on the gov ernor so that the throttle stop screw on the car buretor controls engine speed Adjust the throttle stop screw for 1000 rpm idle 4 Determine the best idle mixture setting by first turning the idle adjustment screw in until engine speed drops and then outward until engine speed drops again Over a narrow range between these two settings engine speed remains at its highest Set the adjustment screw about 1 8 turn outward rich from the midpoi
53. ine is equipped with a paper element If the engine is equipped with polyurethane precleaner it must be removed cleaned and oiled every 25 hours of operation or more under extremely dusty conditions 1 To clean precleaner wash in water and detergent referto Figure 6 Remove excess water by squeezing like a sponge and allow to dry thoroughly GASKET DIAPHRAGM AIRBLEED BASE DIAPHRAGM PUMP PLATE FS 1684 EXPLODED VIEW OF FACET FUEL PUMP Distribute one tablespoon of SAE 30 engine oil evenly around the precleaner Knead into precleaner and wring out excess oil Depending on conditions in which the engine is operating the inner paper element should be re placed whenever it becomes excessively dirty or oily A CAUTION Running engine without air cleaner element will resull in engine damage Do not run engine without air cleaner element installed 1 WASH 2 SQUEEZE DRY 3 COAT WITH OIL 4 INSTALL OVER PAPER ELEMENT ELEMENT COVER ELEMENT j WRAPPER AIR CLEANER AIR ELEMENT DEFLECTOR PLATE BASE FS 1131 FIGURE 6 AIR CLEANER ASSEMBLY T 1 ZA mm BAG THROTTLE STOP THROTTLE SCREW STOP FIGURE 7 DASHPOT CLEARANCE DASHPOT ADJUSTMENT GOVERNOR SENSITIVITY 1 Pull governor arm and linkage away from car buretor until throttle stop contacts throttle stop screw 2 Holding throttle against throttle stop screw adjust dashpo
54. ith damaged threads Replace connecting rods FIGURE 16 MEASURING PISTON CLEARANCE Fitting Piston Rings 1 Install the piston ring in the cylinder bore Invert the piston and push the ring to the end of ring travel about halfway into the bore which trues the ring end gap Check the gap with a feeler gauge Figure 17 The practice of filing ring ends to increase the end gap is not recommended If the ring end gap does not meet specifications check for the correct set of rings and the correct bore size A cylinder bore that is 0 001 Inch 0 03 mm under size will reduce the end gap 0 003 inch 0 08 mm NO NN SOW FIGURE 17 POSITIONING OF PISTON RING AND MEASURING OF END GAP CYLINDER BLOCK The cylinder block is the main support for all other basic engine parts Crankshaft and camshaft are supported by the block assuring alignment of the crankshaft and cylinder bores Cleaning After removing pistons crankshaft cylinder heads inspect block for cracks and extreme wear If block is still serviceable prepare it for cleaning as follows 1 Scrape all old gasket material from block Remove oil by pass to allow cleaning solution to contact inside of oil passages 2 Remove grease and scale from cylinder block by agitating bath of commercial cleaning solution or hot soapy washing solution 3 Rinse block in clean hot water to remove cleaning solution insp
55. ize diameter at which it will clean up The final finish and bore diameters should then be obtained by honing Final bore diameter should equal the standard diameter added to the oversize Improper boring will result in engine ACAUTION damage Boring must be done by qualified mechanics 10 11 TOP END OF CYLINDER SS BOTTOM OF RING TRAVEL FIGURE 18 METHODS OF MEASURING THE DIAMETER OF CYLINDER BORE After boring to the correct oversize cylinder bore dimension piston and ring clearance should be appropriate Thereis no need to adjust or fit pistons and rings When reboring cylinders take the following pre cautions 1 Make sure cutting tool is properly ground before using it 2 Be sure top of engine block is smooth and deposit free 3 Clean base of boring bar before bar is set Deposits under boring bar will cause it to tilt and the cylinder will be distorted after boring 4 Make an initial rough cut followed by a finish cut Then hone cylinder bore to the specified oversize Honing Cylinders Using Precision Hones Refer to hone manufacturer s recommended grit size to produce specified surface finish of 20 to 40 RMS Too rough of a finish will wear out the rings and cause excessive consumption and too smooth of afinish can retard piston ring seating 1 Position block solidly for either vertical or hori zontal honing Use either a drill press or heavy duty drill which operates at appr
56. laced Testing Armature for a Short Circuit Use a growler for locating shorts in the armature Place armature in growler and hold a thin steel blade e g hacksaw blade parallel to the core and just above it while slowly rotating armature in growler A shorted armature will cause the blade to vibrate and be attracted to the core If armature is shorted replace with a new one Figure 7 ES 1002 FIGURE 7 TESTING ARMATURE FOR SHORT CIRCUITS Commutator Inspection commutator is dirty or dis colored clean with number 00 to 000 commutator paper Blow grit out of armature after cleaning If commutator is scored rough or worn turn itdown in a lathe inertia type starter inspection Housing Inspection Permanent magnets are glued to inside of the housing Magnets must be secure and free of cracks Brush Inspection brushes are worn shorter than 1 4 inch 6 35 mm replace them Check to see that brushes move smoothly in the brush holders See Figure 8 0 25 inch 6 35 mm WEAR LIMIT FIGURE 8 BRUSH WEAR LIMIT Pinion Gear pinion gear is badly worn has broken teeth or pinion splined sleeve is damaged replace pinion gear and dust cover assembly If pinion gear is good condition wipe armature shaft spline and pinion clean Solenoid shift type starter inspection Field Coil Use an ohmmeter to check for continuity between brushes If there is no continuity the field coil is
57. linder heads See Cylinder Headsection for torques and torquing procedure Replace oil and break in engine CYLINDER HEADS Remove the cylinder heads for lead cleaning and gasket change at least every 200 hours or when poor engine performance is noticed For engines running on un leaded fuel this interval may be extended to 400 hours 1 Use a 1 2 inch 13 mm socket wrench to remove cylinder head bolts Lift heads off Torquing or removing cylinder ACAUTION heads when hot above 100 F 37 C will result in head damage Allow heads to cool to below 100 F 37 C before torquing or removing 2 After removing heads clean out all carbon deposits Be careful not to damage the outer sealing edges where gaskets fit The heads are made of aluminum and can be damaged by careless handling 3 Use new head gaskets and clean both the heads and the cylinder block thoroughly where the head gaskets rest 4 Place head gasket on the cylinder block and align the holes in the gasket with the holes in the cylinder block While holding the gasket against the cylinder head carefully install the cylinder head on the engine Do not attempt to slide the head bolts through the gasket without the cylinder block behind it or the gasket may tear NO 1 CYLINDER NO 2 CYLINDER C 1002 FIGURE 28 CYLINDER HEAD TORQUE SEQUENCE 10 17 5 Follow the head torque sequence shown in Figure 28 Graphoil head gasket torque proc
58. move blower housing and cylinder air housing 4 Remove flywheel and starter motor Starter Disassembly Inertia Type 1 Remove through bolts and separate end cap housing and armature see Figure 1 2 Disassemble drive assembly and drive end cap by loosening the self locking stop nut 3 Inspect starter for damaged or worn parts 4 Repair or replace all damaged or worn parts as needed Starter Assembly Inertia Type 1 Before reassembling the starter wipe off any dirt from parts with a clean cloth or blow off with filtered compressed air ARMATURE HOUSING BRUSH SCREWS ES 1334 FIGURE 1 STARTER MOTOR INERTIA TYPE 10 Assemble brushes so that the chamfered side is away from the brush springs Make sure brush wires do notrub against the commutator or end cap Torque brush screws to a value of 3 to 3 5 ft Ibs 4 to 5 Nm Torque input stud nut to a value of 4 to 5 ft lbs 5 to 7 Nm Apply a thin film of grease to the commutator end of the armature shaft and to the portion of the shaft that contacts the bearings Apply a generous film of silicone base grease GE Versilube 322 L to the shaft threads Torque stop nut to a value of 20 to 25 ft lbs 27 to 34 Nm Torque through bolts to a value of 4 5 to 6 ft lbs 6 to 8 Nm Apply a small amount of a silicone based grease GE Versilube 322 L to armature shaft spline Install dust cap pinion gear dust cover sp
59. nal of booster battery Attach other end of negative cable to a solid chassis ground on your engine AWARNING Electrical arcing can cause per sonal injury Do not allow positive and negative cable ends to touch 5 Jump starting in any other manner may result in damage to the battery or the electrical system 6 Turn ignition switch to ON to start engine STATOR ofa erate ee OQ a vm oe 20 VOLTAGE REGULATOR N CONNECTIONS B TO STARTER AND IGNITION AWARNING Jump starting a battery incor rectly can cause battery to explode resulting in severe personal injury or death Do not smoke or allow any ignition source near the battery and do not jump start a frozen battery FLYWHEEL ALTERNATOR This unitis equipped with a permanent magnet flywheel alternator and solid state voltage regualtor rectifier output control See Figure 7 As with all solid state electrical units precautions are necessary when ser vicing Observe the following ACAUTION Reversing positive and negative bat tery connections or allowing engine to run without being connected to the alternator will result in engine electrical system damage Do not switch battery connections or allow engine to run without being connected to the alternator Weak ignition spark or a discharged battery indicates trouble in the charging system But before testing the engine s charging system always ch
60. nd perpendicular to axis of crankshaft 2 Record measurements taken at top and bottom of piston travel as follows Figure 18 A Measure and record as the cylinder bore diameter parallel to crankshaft near the top of cylinder bore where greatest amount of wear Occurs Also measure and record as cylinder bore diameter parallel to crankshaft at the bottom of piston travel Measure and record as cylinder bore diameter perpendicular to crankshaft near the top of cylinder bore where greatest amount of wear occurs D Also measure and record as D cylinder bore diameter perpendicular to crankshaft at the bottom of piston travel E Reading A subtracted from reading B and reading C subtracted from reading D indicates cylinder taper If cylinder taper exceeds that specified in D M ENSIONS AND CLEARANCES rebore and hone cylinder to the next oversize F Reading A compared to reading C and reading B compared to reading D indicate whether or not cylinder is out of round If out of round exceeds that specified in DIMENSIONS AND CLEARANCES the cylinders must be rebored and honed to the next oversize A reboring machine is used when going to over size pistons Reboring the Cylinder Rebore and hone engine whenever cylinder bore is worn damaged out of round or if cylinder taper exceeds specifications A worn cylinder bore should be resized to the smallest standard overs
61. nd replace with new ones during assembly Use the following procedures to inspect and service the valve system Inspection Clean carbon from the valves valve seats valve guides and cylinder block Valves Check the valve face for evidence of burning warpage out of round and carbon deposits Burning and pitting are caused by the valve failing to seat tightly This condition is often caused by hard carbon particles on the seat It may also be due to weak valve springs insufficient tappet clearance warpage and misalignment VALVE CLEARANCE VT 1000 VALVE ADJUSTING SCREW VALVE SPRING WASHER LOCK VALVE ROTATOR VT 1005 Warpage occurs chiefly in the upper stem due to its exposure to intense heat Out of round wear follows when the seat is pounded by a valve whose head 1 not in line with the stem and guide If a valve face is burned or warped or if the stem is worn install anew valve Too much clearance in the intake guide admits air and oil into the combustion chamber upsetting carburetion increasing oil consumption and making heavy carbon deposits Carbon reduces heat dissi pation Clean metal is a good heat conductor but carbon insulates and retains heat This increases combustion chamber temperatures which causes warping and burning Unburned carbon residue gums valve stems and causes them to stick in the guide Deposits of hard carbon with sharp points projecting become white hot and
62. nnecting rods in solvent be sure to include the rod bore Blow out all passages with compressed air FIGURE 15 CHECKING RING SIDE CLEARANCE with deep nicks signs of fractures scored bores or bores out of round more than 0 002 inch 2 Use anew piston pin to check connecting rod for wear A push fit clearance is required and varies from engine to engine new piston pin falls through a dry rod pin bore as a result of its own weight replace the rod 21 FIGURE 14 PISTON GROOVE CLEANING en Fitting Pistons Inspection 1 Proper piston tolerances must be maintained Follow the procedures given below when inspecting for satisfactory operation pistons and connecting rods 2 Refer to DIMENSIONS AND CLEARANCES to determine where to measure piston to be sure Piston Inspection the total clearance follows specifications 1 Inspect the pistons for fractures at the ring lands skirts and pin bosses Check for wear at the ring lands using anew ring and feeler gauge as shownin Figure 15 Replace the piston when the side clearance of the top compression ring exceeds that specified in DIMENSIONS AND CLEARANCES 2 Replace pistons showing signs of scuffing Ww scoring worn ring lands fractures or damage from preignition Excessive piston wear near the edge of the top ring land indicates MEASURE CLEARANCE HERE preignition 4 Connecting Rod Inspection 1 Replace connecting rod bolts and nuts w
63. nt of this range On Nikki limited adjustment idle mixture carburetor adjust ments are limited to 1 8 turn Do not go beyond these limits 5 Readjust the throttle stop screw for 1000 rpm idle then adjust the governor low speed stop for 1100 rpm idle 6 Move the engine speed control to the fast posi tion Bend the high speed stop on the governor so the engine runs at the equipment manufacturer s recommended speed 7 Checkthe main mixture adjustment if so equipped by rapidly accelerating the engine from idle to full speed The engine should accelerate evenly and without hesitation If it does not turn the main adjustment screw out in 1 8 turn increments until the engine accelerates smoothly but do not turn it out more than 1 2 turn beyond the original setting 1 2 IDLE FUEL ADJUSTMENT MAIN FUEL ADJUSTMENT FS 1002 WALBRO CARBURETOR LOCATION OF OPTIONAL MAIN FUEL ADJUSTMENT IDLE FUEL ADJUSTMENT FS 1406 NIKK CARBURETOR THROTTLE STOP SCREW IDLE FUEL LIMITER CA FS 1406 2 NIKKI CARBURETOR WITH SEMI AUTOMATIC CHOKE AND LIMITED IDLE MIXTURE SCREW FIGURE 2 CARBURETOR ADJUSTMENTS CARBURETOR OVERHAUL Carburetion problems that are not corrected by mixture adjustments are usually a result of gummed up fuel passages or worn internal parts The most effective solution is a complete carburetor overhaul In general overhauling a carburetor consists of complete disassembly a thorough cleaning and
64. o front bracket with two machine screws 12 Install wire lead to the terminal M on solenoid 13 After assembly adjust pinion clearance Pinion clearance should be 0 020 to 0 080 inch 0 5 to 2 0 mmy if not check as follows See Figure 5 A Connect starter to a battery Figure 5 Close switch This will shift pinion into cranking position B Push pinion back by hand and measure pinion clearance If clearance does not fall within the specified limits adjust by adding or removing shims located between solenoid and front bracket Adding shims decreases clearance removing shims increases clearance Shims are included with replacement solenoid PINION STOP RING SWITCH 4 BATTERY Starter 12N N FRONT BRACKET PINION CLEARANCE ES 1623 FIGURE 5 PINION CLEARANCE ADJUSTMENT Inspection and Testing Inspect the starter components for mechanical defects before testing for grounds or shorts Testing Armature for Grounds Touch armature shaft or core and the end of each commutator bar with a pair of ohmmeter leads A low ohmmeter reading indicates a grounded armature Replace grounded armature See Figure 6 9 4 COMMUTATOR BARS 5 1001 FIGURE 6 TESTING ARMATURE FOR GROUNDS Inspecting for an Open Circuit in Armature Using an ohmmeter check for continuity between the commutator segments If there is no continuity high resistance the segments are open and armature must be rep
65. o 1 64 inch 0 40 mm below the end of the bore Be sure to align the oil holes in the bearing with the oil holes in the bearing bore Figure 21 The oil passage must at least half open Lubricate bearing after installation If head of lock pin is damaged use side cutters or Easy Out tool to remove and install new pin Oil grooves in thrust washers must face the cranksahft and washers must be flat not bent The two notches on each washer must fit over the two lock pins to prevent riding on the crankshaft Figure 21 Lubricate the front main bearing lightly with oil and insert the crankshaft With the rear bearing plate gasket in place and the rear plate bearing lubricated slide the thrust washer grooves toward crankshaft and plate over the end of the crankshaft Line up notches ofthrust washer with lock pins before tightening end plate or lock pins will be damaged CRANKSHAFT ENDPLAY After the rear bearing end plate has been tightened using the torque recommended in ASSEMBLY TORQUES AND SPECIAL TOOLS check the crankshaft endplay as shown in Figure 23 lf there is too much endplay see DIMENSIONS AND CLEARANCES for minimum and maximum endplay remove the rear bearing end plate and add a shim Figure 21 between the thrust washer and plate Reinstall the end plate making sure the thrust washer and shim notches line up with the lock pins Torque and recheck endplay of the crankshaft REAR If uit MEASURE
66. o temperature atmospheric conditions and altitude These pressures are for a warm engine at cranking speed about 300 rpm Tappet Adjustment The engine is equipped with adjustable valve tappets The valve tappet clearance should be checked and adjusted if necessary at least every 200 operating hours or when poor engine performance is noticed Adjust the valve clearance only when engine is at ambient temperature Proceed as follows 1 Remove ignition key to prevent accidental star ting 2 Remove all parts necessary to gain access to valve tappets 3 Remove spark plugs to ease the task of turning the engine over by hand 4 Place a socket wrench on the flywheel capscrew and rotate the crankshaft in a clockwise direction until the left intake valve viewed from flywheel end opens and closes Continue turning the crankshaft until the TC mark on the flywheel is lined up with the TC mark on the gear cover This should place the left piston 1 at the top of its compression stroke Verify that the left intake and exhaust valves are closed and there is no pressure on the valve lifters 5 The correct feeler gauge for the valve adjustment see SPECIFICATIONS should pass freely between valve stem and tappet a 0 002 inch 0 05 mm thicker gauge should not Figure 1 6 To correct the valve clearance use a 7 16 inch open end wrench to turn the adjusting screw to obtain the correct clearance The screw is self locking and w
67. ohibited Fuel System CARBURETOR Most carburetors have a fixed main jet An optional main fuel adjustment kit altitude compensation kit is available The carburetor idle mixture was set for maximum efficiency at the factory and should normally not be disturbed If adjustments seem necessary first be sure the ignition system is working properly and governor sensitivity is properly adjusted If adjustment is needed refer to Figures 1 and 2 and proceed as follows IAC AUTION Overtighiening mixture adjustment screw will cause carburetor damage Turn mixture adjustment screw in only until light tension can be felt 1 Walbro carburetor mixture screw settings Turn both mixture screws in until lightly seated then back the idle mixture screw out 1 1 8 turns and the main mixture screw out 1 1 2 turns ai O HIGH SPEED NJ STOP SS LOW SPEED ADJUSTMENT SCREW lt V CSS VF w FS 1000 SIDE PULL GOVERNOR ASSEMBLY Nikki full adjustment carburetor mixture screw settings Turn idle mixture screw in until lightly seated then back idle mixture screw out 1 1 4 turn On engines equipped with optional main fuel adjustment turn main mixture screw in until lightly seated then back the main mixture screw out as specified below BASE 7 8 to 1 1 8 turns B43G 1 1 4 to 1 1 2 turns B48G 1 5 8 to 1 7 8 turns Nikki limited idle adjustment carburetor mixture screw settings The carburetor has a l
68. om the engine Remove the ridge from the top of each cylinder with a ridge reamer before attempting piston removal Figure 12 Improper piston removal can ACAUTION cause piston damage Use ridge reamer to remove cylinder ridge before removing piston FIGURE 12 REMOVING RIDGE FROM CYLINDER INSTALLING TIMING 10 8 4 Turn the crankshaft until the piston is at the bottom of its stroke and remove the connecting rod nuts Lift the rod bearing cap from the rod and push the rod and piston assembly out through the top of the cylinder using a hammer handle Avoid scratching the crankpin and cylinder wall when removing the piston and rod Mark each piston and rod assembly so they can be returnedto their respective cylinders after overhaul Keep connecting rod bearing caps with their respective rods Remove the piston rings from the piston with a piston ring spreader as shown in Figure 13 Remove the piston pin retainer and push the piston pin out FIGURE 13 REMOVING PISTON RINGS Remove dirt and deposits from the piston surfaces with an approved cleaning solvent Clean the piston ring grooves with a groove cleaner or the end ofa piston ring filed to a sharp point Figure 14 Care must be taken not to remove metal from the groove sides A CAUTION Improper piston cleaning can cause piston damage Do not use a caustic cleaning solvent or wire brush for cleaning pistons When cleaning the co
69. open and must be replaced With field cot mounted in the frame check for continuity between the field coil and frame Replace frame assembly if there is continuity Brushes Clean around brushes and holders wiping off all brush dust and dirt If brushes are worn shorter than 11 5 mm 4528 inch replace them Figure 9 fp 11 5 4528 inch Ss WEAR P LIMIT ES 1193 FIGURE 9 BRUSH WEAR LIMIT Check for shorts between positive side of brush holder and brush holder base If there is continuity replace holder assembly Check for free movement of brushes All brushes should move freely in the brush holders Overrunning Clutch Inspect pinion and spline teeth for wear or damage If pinion gear is worn or damaged inspect flywheel ring gear also Rotate pinion It should turn free when turned in one direction and lock when turned in the opposite direction ACAUTION Cleaning overrunning clutch in liquid cleaning solution will result in starter damage Do not clean overrunning clutch in liquid cleaning solutions Solenoid Push solenoid plunger in and release it The plunger should return to its original position While holding plunger all the way in check for continuity between terminals M and B If there is no continuity replacethe solenoid Figure 10 After replacing solenoid check pinion clearance TERMINAL B TERMINAL S TERMINAL M ES 1345 FIGURE 10 SOLENOID TERMINALS Bushin
70. or distorted Valve Rotators Positive type valve rotators prolong valve life and decrease valve repairs When func tioning properly the valve is rotated a fraction of a turn each time it opens While at open position the valve must rotate freely There is no easy way to determine if a valve rotator is good or bad Onan recommends that valve rotators be replaced at each major overhaul or if a build up of carbon is noted on valve face and valve seat Valve Seats Inspect valve seat inserts If seats are loose cracked or severely pitted new ones must be installed Remove valve seat inserts using a valve seat removal tool If valve seat insert bores in cylinder block are damaged or worn so that a press fit cannot be obtained when installing new standard size valve seat inserts the bores must be machined for an oversize seat USE NEW VALVE SEAT TO ADJUST PULLER DEPTH HEX NUT PULLER JAWS C 1104 FIGURE 4 VALVE SEAT REMOVAL 10 4 Valve Seat Removal Remove carbon and combustion deposits from valve seat Select proper puller size determined by inside diameter of valve seat On some pullers use a new seat as a guide to adjust puller depth Figure 4 Puller jaws must expand into cylinder block at the point where bottom of valve seat insert rests on cylinder block Figure 4 Position puller on valve seat and tighten hex nut Clamp cylinder block to a solid bench Attach slide hammer to puller Tighten hex nut between each bl
71. ow with the slide hammer VALVE SEAT INSERT DRIVER USE PROPER TOOL CHECK THIS SURFACE FOR BURRS BEFORE INSE RTING SEAT VALVE SEAT m AM E E es a 2 VES E as 3 3 7 USE ET VT 1025 FIGURE 5 INSERTING NEW VALVE SEAT Valve Seat Installation After the old seat has been removed clean out any carbon or metal burrs from the seat insert recess Use a valve seat insert driver and hammer to install the insert Figure 5 Drive the valve seat insert in so that the insert enters the recess evenly Make certain that the valve seat insert rests solidly on the bottom of the recess all the way around its circumference Insert valve seat staker into valve seat or guide in cylinder block Using a lead hammer strike the staking tool asharp blow to wedge new valve securely in place It will be necessary to refinish valve seat inserts before installing valves To assure a tight valve seat fit and eliminate the danger of seat loosening in the bore valve seat must be staked TAPPETS Very little wear takes place on tappet diameters or in tappet bores If the clearance between tappet and bore in cylinder block exceeds specifications replace the tappet Inspect the tappet faces which contact camshaft lobes for roughness scuffing or concave wear Replace any worn tappets tappets are worn inspect camshaft for wear VALVE FACE AND S
72. oximately 250 to 450 rpm Follow hone manufacturer s instructions for the use of oil or lubricant on stones Do not use lubricants with a dry hone Insert hone in bore and adjust stones to fit snugly to the narrowest section When adjusted cor rectly the hone should not shake or chatter in cylinder bore but will drag freely up and down when hone is not running Connect drill to hone and start drill Feel out bore for high spots which cause an increased drag on stones Move hone up and down in bore with short overlapping strokes about 40 times per minute Usually bottom of cylinder must be worked out first because it is smaller As cylinder takes a uniform diameter move hone up and down all the way through cylinder bore Check diameter of the cylinder regularly during honing A dial bore gauge is the easiest method but a telescoping gauge can be used Check size at six places in bore measure twice at top middle and bottom at 90 degree angles Crosshatch formed by the stones should form included angle of 23 degrees This can be achieved by moving the rotating hone 250 to 450 rpm up and down in cylinder bore about 40 times per minute Clean cylinder bores thoroughly with soap water and clean rags A clean white rag should not become soiled on wall after cleaning is complete Do not use a solvent or gasoline since they wash oil from the walls but leave the meta particles Dry crankcase and coat it with
73. sem blies such as fuel pump and carburetor can be disassembled and repaired at another time Suggested Disassembly Order 1 Drain crankcase 2 Disconnect all exhaust lines and electrical lines 3 Remove engine from its mountings and place on a suitable bench or work stand 4 Remove all housings shrouds blower housings etc 5 Remove flywheel using a puller 6 Remove the gear cover being careful to protect the seal from keyway damage 7 Remove the crank gear using a gear puller and ring 8 Remove all accessories such as oil filter starter intake manifold fuel lines spark plugs etc 9 Remove breaker point box 10 Remove oil base oil pump and cylinder heads 11 Remove valves springs lifters etc 12 Remove camshaft and gear assembly 13 Remove connecting rods and pistons 14 Remove rear bearing plate crankshaft and front bearing Keep all parts in their respective orders Keep valve assemblies together Return rod caps to their respec tive pistons Analyze the reasons for parts failure Suggested Assembly Procedure Engine assembly is normally the reverse of the disassembly procedure observing proper clearances and torques Use a torque wrench to assure proper tightness Coat the internal engine parts with oil as they are assembled After the internal engine parts are assembled the engine should turn over by hand freely Use only genuine Onan parts and special tools when reassembling your engine
74. t hold the flyballs properly If the distance is less than 7 32 5 6 mm the engine will race especially at no load remove the center pin and press in a new pin TIMING GEARS If replacement of either the crankshaft gear or the camshaft gear becomes necessary always install both gears new The camshaft and gear must be replaced as an assembly Before removing the camshaft and gear assembly remove the cylinder head and valve assemblies Then remove the operating plunger for the breaker points and tappets To remove the crankshaft gear first remove the snap ring and retainer washer then attach the gear pulling ring using two No 10 32 screws Figure 11 Tighten the screws alternately until both are tight Attach a gear puller to the puller ring and proceed to remove the gear Each timing gear is stamped with O nearthe edge The gear teeth must mesh so that these marks exactly coincide when the gears are installed in the engine When installing the camshaft gear and shaft assembly be sure that the thrust washer is properly in place behind the camshaft gear Then install the crankshaft retaining washer and lock ring CRANKSHAFT A A THESE MARKS MUST ALIGN WHEN GEARS VT 1029 FIGURE 11 TIMING GEAR REMOVAL AND INSTALLATION PISTONS AND CONNECTING RODS Observethefollowing procedure when removing pistons and connecting rods from the engine 1 Drain Oil 2 Remove the cylinder head and oil base pan fr
75. t to obtain 0 050 inch 1 27 mm clearance Figure 7 3 Secure dashpot to air cleaner support bracket with hex nut provided Dashpot damage can occur if A CAUTION held with pliers Do not use pliers when securing dashpot 1 8 These engines are adapted for use where a wide range of speed settings is desired Figure 8 Engine speed is controlled at any given point between minimum and maximum by simply shifting the throttle lever on the dash panel until the desired speed is reached The fixed and variable speed governor give an automatic decrease in sensitivity when the speed is increased The result is good stability at all speeds A reliable instrument for checking engine speed is required for accurate governor adjustment Engine speed can be checked with a tachometer Check the governor arm linkage throttle shaft and lever for binding condition or excessive slack and wear at connecting points A binding condition at any point will cause the governor to act slowly and regula tion will be poor Excessive looseness may cause a hunting condition and regulation could be erratic Work the arm back and forth several times by hand while the engine is idling to check for above con ditions If the governor is hunting or not operating properly adjust as follows Figure 8 1 Disconnect linkage A from one of holes C 2 Push linkage A and governor arm as far back toward carburetor as they will go THROTTLE ST
76. this value at governed speed inspect oil system for faulty components 6 3 Check oil pump thoroughly for worn parts Oil pump to prime it before reinstalling Except for gaskets and pick up cup component parts of the pump are not available individually Install new pump assembly if any parts are worn Oil By Pass Valve The by pass valve located to the right and behind gear cover controls oil pressure by allowing excess oil to flow directly back to the crankcase Normally the valve begins to open about 20 psi 138 kPa The valve is non adjustable and normally does not need maintenance Determine if valve is operating normally by inspecting plunger action as follows 1 Remove the 3 8 x 24 x 7 8 cap screw located behind gear cover and under governor arm 2 Remove spring and plunger with a magnet tool 3 Determine proper valve operation by checking the spring and plunger according to the following measurements Plunger Diameter 0 3105 to 0 3125 in 7 89 to 7 94 mm Spring Free Length 1 00 inch 25 4 mm Ee 2 6 0 2 Ibs 11 6 0 9 when compressed to 0 5 inch 12 7 mm 4 Check the valve seat and clean away any accumu lation of metal particles which could cause erratic valve action Verify that the valve seat is not damaged 5 Clean plunger and spring in parts cleaning solvent and install Redistribution or publication of this document by any means is strictly pr
77. till crankcase Run engine until thoroughly warm before draining oil Stop the engine place a pan under the drain outlet and remove the drain plug After the is completely drained clean and replace the drain plug Fill crankcase with correctamount of oil Refer to SPECIFICATIONS for crankcase capacity Use oils meeting the API classi fication SF SF CC or SF CD Refer to chart to determine the proper viscosity grade of oil to use Straight weight oils are recommended for severe duty use and at temperatures above 32 F 0 for minimum consumption ALWAYS REPLACE TIGHTLY OR OIL LEAKAGE MAY OCCUR FULL CAUTION DO NOT OVERFILL 77 ADD ONE PINT 0 5 litre C 1000 FIGURE 1 CRANKCASE OIL FILL A WARNING Crankcase pressure can blow out hot oil which can cause severe personal injury Do not check oil while the engine is running Oil level should beto the FULL mark ofthe dipstick Start engine and run for a short time to check for oil leaks around the drain plug USE THESE SAE VISCOSITY GRADES D TEMPERATURE RANGE YOU EXPECT BEFORE NEXT OIL CHANGE LS 1170 COOLING FINS OIL FILTER C 1001 FIGURE 2 OIL FILTER OIL FILTER CHANGE Refer to Periodic Maintenance Schedule located in the Operator s Manual for oil filter change interval If Operating in extremely dusty high ambient or low ambient conditions change oil more often Spin off oil filter element and discard it
78. topper on the armature shaft Position snap ring in groove in armature shaft Pull stopper all the way over snap ring Figure 4 It may be necessary to tap snap ring into groove witha punch while maintaining tension on stopper OVERRUNNING CLUTCH STOPPER m 3 SNAP RING ES 1194 FIGURE 4 INSTALLING STOPPER Lubrication When starter motor is assembled apply grease to each of the following points Recom mended grade Multemp PS No 2 Armature shaft spline Both bushings Both ends of armature e Stopper on armature shaft e Pinion gear e Sliding portion of lever Fit overrunning clutch into lever and install with armature in the front bracket Install lever retainer and spacer Position frame assembly over armature on the front bracket Install brush holder assembly Position brushes in brush holder Make certain positive lead wires are not grounded Install washers as required on the rear end of armature shaft to obtain an armature shaft thrust gap of 0 05 to 0 5 mm 0 002 to 0 02 inch New washers are required if rear bracket is replaced Table 1 Starter Assembly Torques 54 in Ib 33 in Ib 51 in Ib Solenoid Screws Brush Retaining Screws Through Boits Install rear bracket Secure brush holderto rear bracket with two machine screws 10 Install and tighten the two through capscrews 11 Install solenoid plunger in lever Secure solenoid t
79. tortion and to avoid damaging the bearing bore during removal and installation ALIGN HOLE IN BEARING 10 13 7 32 5 6 mm FROM OUTSIDE WITH HOLE IN BEARING BORE CAMSHAFT BEARING FIGURE 20 FRONT CAMSHAFT BEARING Replacement camshaft bearings are precision type which do not require line reaming or line boring after installation Clean outside of the bearing and bearing bore in the block Before installing cam bearings use Locktite Bearing Mount on outside diameter of bearing Use a combination bearing driver to install bearings Place the bearing on the crankcase over the bearing bore with the lubricating hole front only in the proper position Be sure to start the bearing straight Press in the front bearing flush with the outside end of the bearing bore Front cam bearing oil hole must line up with oiling hole in cylinder block Figure 20 Press in the rear camshaft bearing until past the ignition plunger hole Lubricate bearing surfaces with oil after installing New crankshaft main bearings are precision type which do not require line reaming or line boring after installa tion Use a press or a Suitable driver to remove bearings Support casting to avoid distortion and to avoid dam aging the bearing bore during removal and installation Before installing main bearings expand bearing bore by placing the casting an oven heated to 200 F 94 C If practical cool the precision bearing to shrink it Befor
80. unting Cylinder Head Bolts Cold SC OWS 6 10 8 14 Asbestos Gasket 16 18 22 24 OI PU 7 9 10 12 Graphoil Gasket 14 16 19 22 Valve 1 2 1 3 Rear Bearing Plate Screws 25 27 34 37 Exhaust Manifold Mounting Starter Mounting Bolts 24 26 33 35 SCIOWS iss cus res pa xdi Ps 6 10 8 14 Connecting Rod Bolt 14 19 Other 1 4 Cylinder Block Flywheel Cap Screw 50 55 68 75 Stud and Nuts 7 9 10 12 BaS6 ox a nas 18 23 24 31 Other 5 16 Cylinder Block Stud and Nuts 8 10 11 14 Special Tools The following special tools are available from Onan For further information see TOOL CATALOG 900 0019 Valve Seat Driver Valve Guide Driver Seal Guide and Driver Combination Bearing Remover Main and Cam Combination Bearing Driver Main and Cam Flywheel Puller Redistribution or publication of this document by any means is strictly prohibited Engine Troubleshooting GASOLINE ENGINE TROUBLESHOOTING GUIDE CAUSE RUNI Q LEE Meta Loose Corroded Battery Connection Low or Discharged Battery Faulty Starter Faulty Start Solenoid E m T aen Timing Wong RES m NE n or wa rai PAG oy ME ge at
81. ur FoR 00 TO wea FIGURE 24 MEASURING BEARING CLEARANCE OIL SEALS The bearing plate must be removed to replace the oil seal Figure 25 Drive the seal out from the inside Before installing seals fill the space between lips with a multi purpose grease This will improve sealing When installing the gear cover oil seal tap the seal inward until itis 645 inch 16 4 mm from the front of the gear cover When installing the bearing plate oil seal tap the seal into the bearing plate bore to bottom against the shoulder in the plate bore Use a seal expander or place a piece of heavy paper around the end of the crankshaft when replacing the bearing plate to avoid damaging the seal Remove the paper as soon as the plate is in place REAR BEARING PLATE THIS SURFACE SHOULD BE CLEANED OF ALL OLD SEALING COMPOUND BEFORE INSTALLING SEAL _ DRIVE OR PRESS OIL SEAL TO SHOULDER OF THE PLATE BORE THIS GEAR COVER SURFACE SHOULD BE CLEANED OF ALL OLD SEALING COMPOUND BEFORE INSTALLING SEAL GEAR COVER REAR BEARING PLATE OIL SEAL LS 1163 GEAR COVER OIL SEAL FIGURE 25 GEAR COVER AND REAR BEARING PLATE OIL SEALS 10 15 1 2 PISTON ASSEMBLY Lubricate all parts with engine oil Position piston on its respective rod and install the pin Install the rings on the pistons starting with the oil control ring Figure 26 Use a piston ring spreader to prevent twisting or excessive
82. ve fuel inlet line from fuel pump Ignition of fuel can result in AWARNING severe personal injury or death Thoroughly clean up any spilled fuel Connect a vacuum gauge to fuel pump inlet using piece of fuel hose with clamps 4 Start engine and allow to idle for five seconds Record vacuum gauge reading 5 Move throttle control to high idle position Wait five seconds and record vacuum gauge reading 6 Shut engine off and remove vacuum gauge hose from fuel pump inlet Connect fuel inlet line to fuel pump 7 Remove fuel outlet line from fuel pump AWARNING Ignition of fuel can result in severe personal injury or death Thoroughly clean up any spilled fuel 8 Connecta pressure gauge to fuel pump outlet using a piece of fuel hose with clamps 9 Start engine and allow to idle for five seconds While holding pressure gauge level with pump outlet record pressure gauge reading 10 Move throttle control to high idle position and allow engine to run for five seconds While holding pressure gauge level with pump outlet record pressure gauge reading 1 6 11 Shut engine off and remove pressure gauge hose from fuel pump outlet Connect fuel outlet line to fuel pump Repair or replace the fuel pump if test readings are not within the values specified in TABLE 1 TABLE 1 PULSE PUMP TEST SPECIFICATIONS Engine Pump inlet Pump Outlet Speed Vacuum Pressure Minimum Minimum Low Idle 2 6 inches 1 7 psi of mer

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