ONAN E125 V, E140V ENGINE SERVICE MANUAL Table of Contents – Page 1 of 3 SAFETY PRECAUTIONS GENERAL BATTERIES PROTECT AGAINST MOVING PARTS FUEL SYSTEM EXHAUST SYSTEM EXHAUST GAS IS DEADLY KEEP THE UNIT AND SURROUNDING AREA CLEAN SUPPLEMENT 965-1053 PURPOSE SERVICE MANUAL 965-0764 REVISIONS CARBURETOR (BEGINNING SPEC E) SECTION 1. GENERAL INFORMATION SECTION 2. SPECIFICATIONS SECTION 3. DIMENSIONS AND CLEARANCES SECTION 4. ASSEMBLY TORQUES SECTION 5. ENGINE TROUBLESHOOTING SECTION 6.
ONAN E125 V, E140V ENGINE SERVICE MANUAL Table of Contents – Page 2 of 3 SECTION 9. FUEL GASOLINE CARBURETOR DISASSEMBLY INSPECTION/SERVICE ASSEMBLY CO ADJUSTMENT IMPULSE FUEL PUMP INSPECTION/SERVICE FUEL PUMP REMOVAL FUEL PUMP INSTALLATION LPG FUEL SYSTEM GOVERNOR ADJUSTMENTS 1. GOVERNOR LEVER ADJUSTMENT 2. IDLE SPEED ADJUSTMENTS 3. CHOKE ADJUSTMENT 4. SPEED CONTROL CABLE ADJUSTMENT AIR CLEANER FOAM WRAPPER ELEMENT PAPER ELEMENT SECTION 10.
ONAN E125 V, E140V ENGINE SERVICE MANUAL Table of Contents – Page 3 of 3 SECTION 11.
El25V, El40V Elite Series Printed in U.S.A.
Safety Precautions Beforeoperatingthe engine, read the Operator's Manual and become familiarwith it and the equipment. Safe andefficient If the equipment Is operatloncanbeachievedonly properly operated and maintained. The following symbols, found throughout this manual, alert you to potentiallydangerous conditions to theoperator, service personnel, or the equipment. Thls symbol warns of immediate hazards whlch will result in severe personal Injury or death.
Supplement 965-1053 Date:1-95 lnsert withTitle: E l 25V/E140V Service Manual Number (Date):965-0764(6-94) PURPOSE This Supplement transmits the revisions to the Service Manual necessary for covering Spec €engines. Note that the nameplate on a Spec E engine will have the statement: “This engine meets 1995-1998 California emissions regulations forULGEengines.
SECTION TITLE PAGE Safety Precautions inside cover 1 General Information 1-1 2 Specifications 2-1 3 Dimensions and Clearances 4 Assembly Torques 4-1 5 Engine Troubleshooting 5-1 6 Maintenance 7 Lubrication 8 Electrical 9 Fuel 10 Starting10-1 Engine Block Assembly 11 -1 WARNING INCORRECTSERVICEORREPLACEMENTOFPARTSCAN RESULT IN SEVERE PERSONAL INJURY AND/OR EQUIPMENT DAMAGE.SERVICEPERSONNELMUSTBEQUALIFIED TO PERFORM ELECTRICAL AND/OR MECHANICAL SERVICE.
Section 1 GeneralInformation INTRODUCTION disassembly, inspection, repair, and assembly of the engine components. Thismanualprovidesspecificmechanicaland electrical information needed by engine mechanics Use only Genuine Onan replacement parts to profor troubleshooting, servicing, or overhauling the videqualityandthebestrepairandoverhaul engine. results.
Section 2. Specifications These specifications are in customaryU.S. units of measure with approximate metric equivalents following in parentheses. TABLE 2-1. SPECIFICATIONS UNIT OF El 25V El4OV Number of Cylinders 1 Bore mm (3.31) 84.2 (in) (3.31) Stroke ) rts) SERIES MEASURE SPECIFICATION mm (2.76) Displacement (in) 389 Cm3 389 (in3) (23-7) (23-7) to8.5 8.5 1 to Compression Ratio Power at Rated Speed (3600 rpm) 70.0 10.4 kW (BW 2.5) 1 9.3 (1 (14.
Section 3. Dimensions and Clearances All measurements given at room temperature70°F of (21 "C).Al measurements are given in millimeters with approximate inch measurementsin parentheses. Measurements are for standard size parts. Refer to the headings for notesabout which specs are covered,if the spec is not listed the dimensions cover all specs. TABLE 3-1.
DESCRIPTION ____- I CAMSHAFT SPEC A AND B Lobe- Height, Diameter Over Nose El25 Intake 34.46 (1.357) El25 Exhaust ALLOWABLE LIMIT 34.31 (1.351) 33.81 (1.331) 34.62 (1.363) 34.12 (1.343) 35.33 35.18 (1.391) (1.385) 34.68 (1.365) 35.33 35.18 (1.385) 34.68 (1-365) 34.77 (1.369) E140 Intake El40 Exhaust (1.391) End Clearance 0.10 (0.004) 0.20 (0.008) Oil Base Bearing Clearance (-0020) .0.01 (0004) 0.05 CAMSHAFT BEGIN SPEC C Lobe Height, Diameter Over Nose El25 Intake 0.25 (0.010) .0.08 (.
TABLE 3-3. DIMENSIONS AND CLEARANCES DESCRlPTlON FACTORY SPECIFICATION MIN MAX PISTON SPEC A AND B Piston SkirtO.D. 90 deg to Pin, 26.5 from Top of Piston .25Oversize 84.09 (3.311) (3.322) 84.37 84.34 (3.320) (3.331) 84.62 84.59 (3.330) 50 Oversize Pin Bore I.D. 20.000 (0.7874) PISTON BEGIN SPEC C Piston Skirt O.D. deg to Pin, 26.5 from 90 Top of Piston84.1 84.09 (3.311 ) .25Oversize (3.322) 84 8. 43 .7 34 (3.320) (3.331) 84.62 84.59 (3.330) 50 Oversize Bore Pin I.D. (0.7879) 20.02004.
TABLE 3-4. DIMENSIONS AND CLEARANCES FACTORY SPECIFICATION DESCRIPTION ALLOWABLE LIMIT PISTON RINGS Top Compression Ring Thickness 1.47 Second Compression Ring Thickness Top Compression Ringto Ring Groove Clearance Second Compression Ring to Ring Groove Clearance Top Compression Ring End Gap 1.40 INTAKE VALVE Valve Stem O.D. Valve Guide I.D. Valve Stem to Guide Clearance E l 25V Valve Lash (0.002) 1.49 (.059) 1.42 t.056) 1.47 (.058) 1.49 (.059) 1.42 (-056) 0.03 (0.001) 0.08 (0.003) 0.
TABLE 3-5. DIMENSIONS AND CLEARANCES DESCRIPTION EXHAUST VALVE (cont) E125V Valve Lash 0.075 (-003) 0.1 5 (-006) E140V Valve Lash FaceAngle 0.25 (0.010) 0.25 (0.01 0) 45" EXHAUST VALVE SEAT Seat Width 1.7 (0.067) SeatAngle VALVE SPRINGS INTAKE AND EXHAUST SPEC A AND B Valve Spring Free Length (Approx.) 43.5 (1.71) Valve Spring Length Valve Closed 32.6 (1.28) ValveOpen 23.2 (0.91 ) Spring Load (Valve Closed Length) 5.67 kg (1 2.5Ib) 6.62 kg (1 4.
-"-AND CLEARANCES DESCRIPTION FACTORY SPECIFICATION MIN MAX -__.__I- ALLOWABLE -_I___-__ ROCKER ARM Rocker Arm Inside Diameter 12.000 (0.4724) 12.018 (0.471 8) Rocker Arm Shaft O.D. 11.973 (0.4714 11.984 (0.471 8) Rocker Arm to Shaft Clearance 0.016 (0.0006) 0.045 8) (0.001 0.15 (0.0059) *----_I- LUBRICATING SYSTEM Engine Oil Pressure At Idling At 3300 rpm Rotor Lobe Clearance Outer Rotor to PumpBody Clearance 0.19 3.0 psi or more 14.0 psi or more 4.0 psi 0.15 or less ( 0.
Section 4. Assembly Torques Thetorquevalueslisted in Table 4-1 havebeenTighten all studs, nuts andcapscrewsasspecified determined for specific applications. The engine to keep them from working loose. Refer to the Parts assemblytorquesgivenhere will provide proper Manual for the location of washers and capscrews. tightness without danger of stripping threads. All threads must be clean, rust free andlightly lubricated. TABLE 4-1.
5-1
Section 6. Maintenance PERIODICMAINTENANCESCHEDULE Neglectingroutinemaintenance wil result in poor performance and reduced engine life. Keep an accurate logbook of maintenance, service, and operating time: Follow a regular schedule of inspection and service, based on operating hours. WARNING Incorrect service or replacement of parts can result in severe personal Injury and/or UsethefactoryrecommendedPeriodicMainteequipment damage.
ENGINE INSPECTION Do not the and Check the fuel lines and fittings for leaks. start engine until leaks are repaired. WARNING Breathing exhaust gases can result in severepersonal injury or death. Inspect the exhaust system audibly and visualiy for leaks daiiy and repair leaks immediateiy. CLEANER AIR AND ELEMENT WRAPPER Refer to Air Cleaner,in section9, for disassembly, assembly procedures. OIL CHANGE Refer toOil Change, in section 7, for inspection and service procedures.
Section 7. Lubrication A pump driven by one of the balancer shafts pro- the drain plug and remove the plug (open the drain videspressurelubricationoftheconnectingrod cock). Replace the drain plug (close the cock) when journal through drilled passages in the crankcase the oil has stopped draining. Refill with oil meeting and crankshaft.
OIL LEVEL CHECK WARNING Crankcase pressure can blow out hot oil, which can cause severe personal injury Do not check oil while the engine is running. Correct oil level in the crankcaseis required to insure proper lubrication and prevent saturating the air cleaner paper element with oil. Always check the oil with the engine stopped and on a level surface. When checking oil the level, always screw the oil fill cap into the dipstick tube until it lightly seats on the oil fill tube.
OIL PRESSURE RELIEF VALVE Refer to Figure 7-2. On Specs B and C the oil relief valve is accessible only after the oil base has been removed. The check ball and spring are retained by a retainer ring. On Spec A the oil pressure relief valve is removable form the outside by removing the retaining bolt. SPECS B AND C I ? Wash all components in solvent and allow themto dry. Inspect the components for damage and wear. Replace partsas necessary.
OIL PUMP Disassembly Refer to Figure 7-3. Remove the capscrews holding the oil pump cover to the oil base. Separate the inner and outer rotor. FIGURE 7-3. OIL PUMP DISASSEMBLY I Rotor Lobe Clearance Refer to Figure 7-4. Measure the clearance between the inner rotor lobes and the outer rotor lobes Ifclearance is not as specified with a feeler gauge. in Dimensions and Clearances, replace o i l pump. *----- FIGURE 74.
Outer Rotor and Pump Body Clearance Refer to Figure 7-5.Measure the clearance between the outer rotor and the pump body with a feeler gauge. If the clearanceis not as specified in Dimensions and Clearances,replace the oil pump. FIGURE 7-5. MEASURING OUTER ROTOR TO PUMP BODY CLEARANCE Rotor and Cover Clearance Refer to Figure7-6.Place a strip of plastigauge on the rotor face. Install the pump cover and tighten the screws to that specified in ASSEMBLY TORQUES.
Section 8. Electrical ~ W A R N I N Gincorrect ~ service or replacement of parts can result in severepersonalinjury and/or equipment damage. Service personnel must be qualified toperform electrical and/or mechanical service. IGNITION SYSTEM Spark Plug REMOVAL:Cleanthe area around the sparkbe-plug fore removingit. Remove the spark plug lead from spark plug. Remove the spark plug from the cylinder head. Refer to Figure 8-1.
Ignition Coil Measuring Coll/Flywheel Clearance: Referto Figure 8-2. Measure the clearance between each Spark Test: If the engine will not start conduct a pole face of the coil and the magnet on the flywheel. spark test as follows: If the clearance is not as specified in Dimensions andClearances, loosenthe two coilmounting WARNING Gasoline and LPG vapors are extremely flammable and can cause severe Injuryscrews and adjustto specifications. or death if ignited.
FLYWHEEL ALTERNATORS is equipped with 110 a VAC starter When the engine motor and/or recoil starter a permanent magnet flyWhen the engineis equipped with a12 VDC starter wheel alternator and fullbridge rectifier may be promotor a permanent magnet flywheel alternator and vided for the customer DC interface (clutch, hour electronic voltage regulator may be provided for meter, etc.). Refer to Figure 8-4. The 110 VAC startbattery charging. Refer to Figure 8-3.
Alternator Output Tests Keep the following points in mind when testing or servicing the flywheel alternator. gine is running between1800and 3600 RPM. Refer to Table 8-1 for test specifications.Use a multi-meter (Simpson270) when testing the alternator. 1. Check battery voltage when the engineis not running. (Not applicable on recoil or110 VAC starterengines.) If notwithinspecifications (Table 8-l),charge the battery before going to Step 2. 1. Never reverse the battery leads. 2.
TABLE 8-1. ALTERNATOR OUTPUT TEST SPECIFICATIONS ALTERNATOR BATTERY VOLTAGE VOLTAGE REGULATOR OUTPUT Non-Battery Charging Alternator 5 Amp Battery Charging Alternators 12 to 13 VDC 13.6 to 14.7 VDC at Any Speedin Operating Range 15Amp Battery Charging Alternators 12 to 13 VDC 13.6 to 14.7 VDC at Any Speed in Operating Range 20 Amp Battery Charging Alternators 12 to 13 VDC 13.6 to 14.7 VDC at Any Speed in Operating Range Spec A 2.
. Section 9. Fuel 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 mechanlcal service. ~AWARNING] IDLE MIXTURE LOW IDLE /AWARNING1 Accidental 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 associated equipment.
CARBURETOR (BEGINNING SPEC E) Carburetor Replacement TAMPER-RESISTANT PLUG OVER IDLE MIXTURE NEEDLE THROTTLE LEVER Other than replacing the carburetor main fuel jet (fixed-type) with the optional high-altitude jet(Fig-. ure9-3a),fuelmixture adjustments should not be attempted.Norshouldthecarburetorbeoverhauled. Instead, a malfunctioning carburetor should be replaced.
Replace the carburetor if there is excessive playin the choke and throttle shafts. Replace the idle adjustment needle if it is bent, worn or damaged in any way. Assembly CAUTION The mixture adjustment screw is easiiy damaged. Turn the mixture adjustment screw in only until light tension can be feit. LOW IDLE When installing the idle adjusting screw, turn the screw in until LIGHT tensionis felt. For SpecC turn the screw out 3-1/8 turns. ForSpecs A and B turn the screw out 2-1/2 turn.
performance. Also check the sealon the oilfill tube. The engine may be equipped with an impulse type 7. I f the gasoline has been stored for an extende fuel pump that uses crankcase pressure (vacuum) time, drain and properly dispose ofold the gaspulses to operate a spring loaded diaphragm inside oline. Refill the fuel tank with fresh unleaded thepump to pumpthefuelthrough two check regular gasoline. valves.
Fuel Pump 'Removal 7. Disconnect the from hose -fuel inlet Refer to Figure 9-3. The pumpis not intended to be rebuilt and should be replaced as a complete aspump sembly. the fuel pump. 8. Disconnect the outlet fuel hose from the fuel (it may be necessary to loosen the air cleaner pan mounting screws to gain access to the fuel pump). 9. Remove the fuel pump. 1. Turn off the fuel shutoff valve at the tank. 2. Place a drip pan under the fuel pump and carburetor to collect fuel. 3.
LPG FUEL SYSTEM Referring to the block diagram,. operation of the LPG fuel systemis as follows: Refer to Figure 9-4. The carburetor, gas pressure regulator, air pump and vacuum sustain valve com1. Crankcase vacuumpulses cause theair pump prise theLPG fuel system components that are part to pump clean air from the air cleaner to the of the engine assembly. A vacuum cutout deviceis vent side of the gas pressure regulator, which provided by the equipment manufacturer.
GOVERNOR ADJUSTMENTS Spec B gasoline enginesthelever is clamped around the straight shanked governor shaft with a In order to obtain the best performance from the draw bolt and nut. Before removing the lever, stop equipment it is essential that the governor lever, lowthe engine and disconnect the throttle link and govandhigh idle speeds,chokeandspeedcontrol ernor spring. For Spec C gasoline engines use a cable be adjusted properly.
I CONTROL LEVER GOVERNOR SHAFT SPEC C GASOLINE ENGINES GOVERNOR SPRING LPG ENGINES SPEC B GASOLINE ENGINES FIGURE 9-5.
2. Idle speed Adjustments WARNING Too high a speed settlng can cause severe personal injury or death-Follow the low and high manufacturer’s speclfications for idle speedsas found in the equlpment Owner’s Manual. Usean accurate tachometer SPEED CONTROL CABLE CLAMP 9/64 IN. (3.5 mm LOCK PIN HOLE 9-6. High Idle Speed Adjustment; Refer to Figure 1. Set up the tachometer according to the instructions with the tachometer. 2.
3. Choke Adjustment Refer to Figure 9-8. Proper choke adjustment is essential for obtaining consistent starting at low temperatures and wide open operation under normal running conditions. SPECS BAND C 9/64 IN. (3.5 mm) 1. Shut off the engine and loosen the choke rod 2. 3. 4. 5. 6. 7. clamp screw so that the rodis free to movein the choke swivel.
4. Speed Control Cable Adjustment Refer to Figure9-9. The speed control cable must be installed properly to obtain full-load, full-speed operation. Adjust the speed control cable as follows: PULL CABLESHEATH THIS WAY TO REMOVE CABLE SLACK 1. Stop the engine and loosen the speed control CONTROL cable clamp located on the engine throttle con- SPEED PIN LOCK CLAMP CABLE trol plate. 2. Push the speed control lever on the equipment to the high speed position.
AIR CLEANER Foam Wrapper Element Install the foam wrapper over the paper air cleaner element by stretching over the inner cover. Completely cover all exposed paper pleats on the air cleaner paper element. If the foam wrapper has stretched or become tom, replace the foam wrapper. Assemble the outerair cleaner cover and nut. Refer to Figure 9-9. See Periodic Service Schedule for foamwrapperserviceinterval.Removethe outer air cleaner nut and plastic outer cover.
Section 10. Starting WARNING Incorrect service or replacementof 110 VAC STARTER parts can result in severe personal injury and/or Disassembly: Refer to Figure 10-2. Remove the equlpment damage. Service personal mustbe two drive cap mounting screws and remove the asqualified to perform electrical and/or mechanlsembly from the engine. cal service Accidental starting of the englne can result In severe personal Injury or death.
SOLENOID SHIFT STARTER WARNING Accidental starting of the engine can result In severe personal Injury or death. Disconnect the negative (-) battery cable and spark plug wire before servicing the engine, controls, or associated equipment. Inspection/Service: With the starter assembled, disconnect the connecting lead from the starter solenoid C terminal. Connect a jumper lead from the connecting lead to the battery positive terminal.
Armature Armature Coil Core and Commutator Continuity: Refer to Figure 10-6. Check for no continuity beContinuity Between Segments: Refer to Figure tween the commutator and armature’s shaft. If con10-4. Check for continuity between the segments oftinuity exists, replace the armature. the commutator.If there is no continuity, replace the armature. COMMUTATOR commutator FIGURE 106. MEASURING ARMATURE SHAFT AND COMMUTATOR CONTINUITY ES1872 flGURE 10-4.
MICA UNDERCUT SEGMENT EDGES DEPTH SAW BLADE PINION SIDEOF ARMATURE SHAFT ES-1877 FIGURE 10-8. MEASURING ARMATURE SHAFT OUTSIDE DIAMETER ES-1879 FIGURE 10-10. MICA UNDERCUT DEPTH Commutator And Mica Commutator:Refer to Figure 10-9. Clean commutator surface with sandpaper. Measure the commutator outside diameter at several points. If the difference of the outside diameteris not as specified in Dimensionsand Clearances,correct the commutator on a lathe to factory specifications.
Brushes 10-12. Inspection/Service RefertoFigure Clean the brush base with sandpaper. Measure the brush length. If the length is not as specifiedin Dimensions and Clearances, replace the starter body and brush holder. age. Do not clean overrunning clutch in liquid cleaning solutions. Inspection/ServiceRefer to Figure10-13. Inspect the pinion and spline teeth for wear and damage. If wear or damage exists, replace pinion. Rotate the pinion clockwise and seeif it turns freely.
Section 11. Engine Block Assembly INTRODUCTiON Suggested Assembly Procedure This section covers service procedures for the enEngine assemblyis normally the reverseof the disgine block assembly. A compression test can be assembly procedure, observing proper clearances performed to determine the condition of the engine. and torques. Use a torque wrench to assure proper WARNING Accidental starting of the engine tightness.
Compression Clean tapered section of the flywheel so no oil or dirt are present. Install woodruff key on the crankshaft. Install flywheel on crankshaft and tighten to torque specified in Assembly Torques. Install sheet metal. in Assembly The compression tester is used to determine the condition of valves, piston, piston rings and the engine cylinder. specified torque Tocompression: check to Tighten bolts Torques. 1. Run the engine until thoroughly warm. 2. Stop engine theand remove spark the plug.
ROCKER SNAP RING VT-1050 FIGURE 11-1. ROCKERARM ASSEMBLY CYLINDER HEAD Disassembly Torquing or removlng the cylinder head when hot (above100F[37C] wlll result in head damage. Allow the head to cool to below 100F(37C)before torquing or removlng. Refer to Figure11-2. The engine mustbe at room temperaturebeforestartingthisprocedure.Remove the valve cover capscrews and valve cover. Remove the spark plug. Remove the rocker arm assembly by unscrewing bolt holding the assembly on. Pull out the push rods.
essential for good engine performance. Use the following procedures to inspect and service the valve system. Assembly CAUTION Over torquing bolts can cause en- gine damage. Do not over torque nuts. Tappets Refer to Figure 11-2. Install a new cylinder head gasket. Position cylinder head on engine and posiVery little wear takes place on tappet diameters or in tionrockerarm,bolts,andwashers inpositions tappet bores. If the clearance between tappet and shown.
VALVE GUIDE Valve Stem and Valve Guide Clearance: Refer to Figures 11-4 and 11-5. Remove carbon from valve guide and valve stem. Measure the valve stem outside diameter six at positions. Measurethe valve guide inside diameter at three positions. Calculatetheclearance. If the clearance is not as specified in Dimensions and Clearances, replace the valve. If clearance still exceeds the allowable limit, replace the valve guide. FIGURE 11-5.
Assembly Clean off any carbon onthe valve stem and valve guide hole. Apply engineoil to the valve and valve guide. Assemble in reverse of disassembly procedures. wheel. A very light grind is usually enough to square the stem and remove anypits or burrs. The valve guide should be thoroughly cleaned. If the valve guide is worn, o r the valveis warped, the necessary parts must be replaced. 45" angle on a valve refacRefinish valve faces ato ing machine. The first cut from valve face be must a light grinding.
valve and seat. Repeat the lasttwo steps untilthe correct, contact is achieved. Lap valve until the seated rate becomes more than 70% of the total contact area. Inspection/Service Valve Seat Width: Clean the valve seat surface. Measure the valve seat width. Apply red lead to the valve surface to check for scratches and unevenness.If the measurement is within that specifiedin Dimensions and Clearances, check the seating ratio. If the ratio is less than70%, refit it.
Shim as necessary to obtain the clearances specified in Dimensions and Clearances. The engine must be at room temperature when performing this test. Remove the valve cover. Remove Apply grease to the oil seal lip and make sure it's not until the piston the spark plug. Turn the engine over damaged when installing the oil base. Be sure the is at COMPRESSION TOP DEAD CENTER. Check oil pump shaft lines up with the slot on the balancer the intake and exhaust valveclearance with a feelershaft.
BALANCER SHAFT 2 BALANCER *-I CT-1110 FIGURE 11-14. BALANCINGSHAFT ALIGNMENT CT-1089-1a RETAINER CRANKSHAFT AND CAMSHAFT FIGURE 11-13. GOVERNOR Disassembly BALANCING SHAFTS Set the engine blockon the flywheel side. Pull the crankshaftoutwiththecamshaft.Removethe tappets. Disassembly Carefully pull each shaft out, one at a time. Oil Base Bearlngto Shaft Clearance: Measure thebalancerjournalbearing O.D. onboth balancershafts.Measurethecorresponding oil base bearingI.D.’s.
Oil Base Bearing to Camshaft Clearance: OIL Measure the camshaft journal bearing O.D. Measure the corresponding oil base bearingI.D. If the measurements are notas specified in Dimensions and Clearances, replace the defective parts. CRANKSHAFT JOURNAL RADIUS Assembly Install tappets into the block. Refer to Figure 11-17. Apply engine oil to the governor lever shaft. Apply grease to the oil seal lip and be careful not to roll the seal when inserting the crankshaft.
COMPRESSION RELEASE SYSTEM ENGINE START POSITION This engine has a compression release that, system decreases the amount of effort required to start the engine and reduces engine run-on when stopping (Figure 11-18). CAM GEAR I TAPPET FLYWEIGHT The system works as follows: 1. As the engine is started, a spring holdsin the flyweight, which in turn pushes a decompression pin upward. 2.
PISTON, PISTON PIN, RiNGS, CONNECTING ROD Disassembly CAUTIONImproper piston removal can cause piston damage. Use a rldge reamer to remove cylinder ridge before removing plston. Refer to Figure11-19. Unscrew the connecting rod screws and remove the connecting rod cap. Turn the crankshaft so the piston is at top dead center. Pull the piston and connecting rod out of the cylinder liner. Make a mark on the pistonon the same side as the machined surface on the connecting rod.
Piston Pin Hole inside Dlameter: Piston' Ringand Ring Groove Clearance: Refer to Figure 11-21. Measure thepiston pin hole inside diameter at various places. If the measurement is not as specifiedin Dimensions and Clearances, replace the piston. Refer to Figure11-23. Remove carbon from the ring grooves.Insert a newpistonringintothering grooveandmeasuretheclearanceatseveral in points. If the measurements are not as specified Dimensions and Clearances,replace the piston. .1100 FIGURE 11-21.
Assembly Connecting Rodto Crankshaft JournalOil Clearance: Referto Figure77-26. Immerse the piston in 212°F oil for 10 to 15 minutes and then insert the piston pin Refer to Figure 11-25. Measure the crankshaft jour- into the piston and connecting rod. Be sure the connal outside diameter with an outside micrometer. If necting rod machined surface is on the same side as the pistonmark.
Refer to Figure 11-28. Insert piston pin snap ring. Position rings on piston as shown. Gap on top ring must face opposite of intake and exhaust valves. SECOND TOP RING Refer to Figure 11-30. Use a ring compressor to insert the piston and connecting rod in into the cylinder liner. Apply engine oilto the inside diameter of rod screws. the connecting rod cap and connecting Align the machined surfaces of the connecting rod and connecting rod cap.
.Inspection When rebuilding the engine, thoroughly inspect the it unfit for block for any condition that would make further use. This inspection must be made after all parts have been removed and the block has been thoroughly cleaned and dried. 1. Makeathoroughcheckforcracks.Minute cracks may be detected by coating the suspected area with a mixture 25 of 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.
1. Position block solidly for either vertical or horizontal honing. Use eitherdrill a pressor heavyRebore and hone the engine whenever cylinder duty drill which operates at approximately 250 bore is worn, damaged, out of round, or if cylinder to 450 rpm. taper exceeds specifications.A worn cylinder bore 2. Follow hone manufacturer's instructions for the should be resized the to smallest standard oversize use of oil or lubricant on stones. Do not useludiameter at which it will clean up.
Deglazing Cylinder Bore Deglaze the cylinder bore if there are no scuff marks and no wearor 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 holdoil during piston ring break-in. PRODUCE CROSS HATCHSCRATCHES FOR FAST RING SEATING AVOID THIS FINISH 1.
