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Onan NHE-NHEL Genset Service Manual

1. Service Manual NirllesINIAleL GenSets RV Electric Generating Set Spec A C 940 0502 7 OFT Redistribution or publication of this document by any means is strictly prohibited Safety Precautions Before operating the generator set read the Operator s Manuai and become familiar with it and the equipment Safe and efficient operation can be achieved only if the unit is properly operated and maintained Many accidents are caused by failure to follow fundamental rules and precautions The following symbols found throughout this manual alert you to potentially dangerous conditions to the operator service per sonnel or the equipment TOPLAS This symbol warns of Immediate haz ards which will result In severe personal injury or death jaWARNING This symbol refers to a hazard or unsafe practice which can result in severe personal injury or death l CAUTION This symbol refers to a hazard or unsafe practice which can result In personal injury or prod uct or property damzge FUEL AND FUMES ARE FLAMMABLE Fire explosion and personal injury can result from improper practices e DO NOT fill fuel tanks while engine is running Fuel contact with hot engine or exhaust is a potential fire hazard DO NOT SMOKE OR USE AN OPEN FLAME near the gen erator set or fuel tank Fuel lines must be adequately secured and free of leaks Fuel connection at the engine should be made with an ap flexible
2. Place the bearing plate gasket in position on the block making sure the oil hole on the back of the block is exposed Install the rear bearing plate and fasten with two nuts or capscrews tightened to the specified torque Make sure the rear thrust washer and shim s did not slip out of place during instala tion The crankshaft should turn freely by hand Checking Endplay After tightening two rear bearing plate nuts or caps crews to the specified torque check the crankshaft endplay at the point shown in Figure 9 28 using a feeler gauge Lightly tap the front of the crankshaft with a plastic faced hammer to take up the freeplay Referto Dimensions and Clearances Section 3 for the recommended crankshaft endplay lf necessary remove the rear bearing and plate and add or remove shims as required Install the end plate and tighten all nuts or capscrews to the specified torque Make sure the shim and thrust washer are in place and recheck crankshaft endplay Verify that the crank shaft turns freely without binding H REAR ititi H MEASURE ENDPLAY HERE REFER TO DIMENSIONS AND CLEARANCES cT 1068 FIGURE 9 28 CHECKING ENDPLAY CYLINDER BLOCK The cylinder block is the main support for ail other basic engine parts Crankshaft and camshaft are supported by the block assuring alignment of the crankshaft and cylinder bores Power 9 12 Generation Redistribution or publication of this document by a
3. REAR PANEL ASSEMBLY SUPPORT TRAY EXS 1122 SUPPORT BRACKET FIGURE 5 2 TYPICAL UNDER FLOOR INSTALLATION ate Power a 9 4 Redistribution or publication of this document Generation by any means is strictly prohibited GLLLLLLLLLLLLLLLLL LA bd flip Ri A FRONT NA WA SUPPORT BRACKET DRIP TRAY BOLTS 4 PLACE FLOOR JACK UNDER DRIP TRAY M 1600 REINFORCEMENT RIBS FIGURE 5 3 PARTIAL SET REMOVAL This might require slight adjustment of the floor Complete Set Removal Park the recreational vehicle jack either slight raising or lowering of the jack on a level surface Then follow these steps very 5 Once the support bracket is removed all the carefully weight of the generator set on that side is on the floor jack Slowly lower the floor jack being care ful to allow the floor jack to roll as the generator Itis assumed that disconecting the fuel exhaust etc has already been performed as described on the pre set swings downward vious page 6 Onan suggests you putsome wood blocksunder 4 But the vehicle in its park position lock the the drip tray assembly so that you can remove the brakes and remove the ignition key Make sure eae oe ae ae no one moves the vehicle while performing this P l procedure Dropping the generator set AWARNING creates the hazard of severe personal injury or death Make sure generator setis rasting securely before removing floor jack Ea Power 9 5 sean re Ge ration Redistribution or
4. itis important that the breaker points have the correct gap for easy starting efficient operation full power and proper cooling A retarded ignition will reduce efficiency while an advanced ignition will cause overheating The condenser extends point life by preventing arc ing across the opening breaker points A defective condenser causes a weak spark and rapid point wear Replace the condenser if defects are suspected A new condenser is supplied with the engine tune up kit Breaker Point Replacement and Adjustment Inspect the breaker points at the interval specified in the Operators Manual and replace if pitted or burned Filing of the points is not recommended Use the following procedure to replace and adjust the points The ignition adjustments should be made with the engine in a static condition and cold 1 Disconnect the negative battery cable at the battery terminal 2 Remove the breaker box cover clip and lift off the breaker box cover 3 Remove the spark plugs to permit easy rotation of the engine and generator assembly Using a hex head socket and socket wrench turn the rotor through bolt in a clockwise direction until the breaker point gap is open the maximum amount 4 Remove the condenser mounting screw screw A and disconnect the condenser and ignition lead wires screw B Lift out condenser see Fig ure 6 6 Power Generation Redistribution or publication of this document by any means i
5. 50 F 10 C 55 F 13 C 60 F 16 C 65 F 18 C 70 F 21 C 75 F 24 C 80 F 27 C 85 F 29 C 90 F 32 C SAB 95 F 35 C 100 F 38 C FS 1606 Each mark on choke housing equals 5 angular rotation FIGURE 6 20 BI METAL SPIRAL STRIP Power n 6 17 Redistribution or publication of this document Generation by any means is strictly prohibited om 4 Refer to Table 6 3 to determine the number of degrees element cover must be rotated clock wise from reference position Marks on choke housing are spaced at 5 intervals 5 Rotate element cover as specified and then tighten cover mounting screws 6 Move choke lever back and forth to check for smooth operation Lever should return automati cally to the free position when released from the open position without sticking or binding 7 Install plastic choke cover and tighten center mounting nut Choke Replacement f the choke fails to open remove the protective plastic cover and check to see if the heating element is working The heating element cover should become hot after a few minutes of operation If the element cover does not get hot start the set and then use an AC voltmeter to check for voltage approx imately 20 VAC at the element cover terminals If voltage is not present check for opens or shorts in the control wiring lf the voltage is present at the heating element cover terminals stop the set and remove the hea
6. C subtracted from reading D indicates cylinder taper if cylinder taper exceeds 0 003 inch 0 08 mm rebore and hone cylinder to the next oversize Power 9 13 Generation Redistribution or publication of this document by any means is strictly prohibited om F Reading A compared to reading C and reading B campared to reading D indi cates whether or not cylinder is out of round Hf out of round exceeds 0 003 inch 0 08 mm the cylinders must be rebored and honed to the next oversize Areboring machine is used when going to oversize pistons The following repair data covers honing to oversize by use of a hone Reboring the Cylinder Kebore 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 oversize diameter at which it will clean up The final finish and bore diameters should then be obtained by honing lf boring bar is operated incorrectly ACAUTION it will produce a rough cylinder sur face that may not clean up even when honed Boring should be dane only by qualified service personnel who are careful in their work After boring to the correct oversize cylinder bore dimension piston and ring clearance should be appropriate There is no need to adjust or fit pistons and rings When reboring cylinders take the following pre cautions
7. FIGURE 9 16 OIL PUMP ASSEMBLY Circumferential grooves in the main bearings supply oil to the connecting rod bearings through drilled passages from each main journal A drilled passage connects the front main bearing oil Supply to the front camshaft bearing The oil overflow from the bypass valve furnishes lubrication to the camshaft drive gears Normal oil pressure should be 30 psi 207 kPa or higher when the engine is at normal operating temper ature If pressure drops below this value at governed speed inspect the oil system for faulty components Check the oi pump thoroughly for worn parts Oil the pump to prime it before reinsialling Except for gaskets and pick up cup the component parts of the pump are not available individually Install a new pump assembly if any parts are worn Oil By Pass Valve The by pass valve facated to the right and behind gear cover Figure 9 17 controls oi pressure by allowing excess oil to flow directly back to the crank Power 9 7 Generation Redistribution or publication of this document by any means is strictly prohibited om PISTON ASSEMBLY HEX CAPSCREW The piston assembly consists of the piston piston 7 JH FL rings piston pin connecting rod assembly and bear p ing After removal from the engine all parts must be s FLAT WASHER carefully inspected for damage and wear before i replacing a i p SPRING Removal and Disassembly CEE i Remove carbon from top
8. NOTE Do not add additional thrust washer when replac ing front bearing FRONT MAIN BEARING BORE z ED LOCK Pin Se LOCK PINS AND MATCH OIL HOLES FRONT MAIN BEARING PRECISION TYPE DO NOT LINE BORE OR REAM OR BORE M 1476 FIGURE 9 33 FRONT BEARING 9 15 Redistribution or publication of this document by any means is strictly prohibited block Apply the Locktite Bearing Mount to the mat ing surfaces of the bearing and bearing bore Allow three to four minutes for drying Breathing vapor from toweleite and AWARNING prolonged contact with skin can cause severe personal injury Be sure area is well ventilated Use the combination main and cam bearing driver and a press to install the front bearing Push in the bearing to the depth allowed by the flange on the driver Wipe off any excess Locktite and allow one hour for hardening at room temperature Engines shipped from the factory have separate thrust washers and main bearings for both front and rear of engine Front bearing replacement is one piece bearing with attached thrust washer as shown in Figure 9 33 Do not add an additional thrust washer to this front bearing OIL SEALS Remove the rear bearing plate to replace the rear oil seal Remove the gear cover to replace the front oil seal Use an oil seal remover to pry out the front or rear oil seal Use an oil seal guide and driver to press or drive the rear seal into the rear bea
9. Power 6 15 Generation Redistribution or publication of this document by any means is strictly prohibited om 1 Slide in throttle shaft and install throttle plate using new screws if furnished in repair kit Before tightening 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 gently tapping with a small screwdriver then tighten screws Install the choke shaft and plate in the same manner T owe AND WEAR OCCUR HERE gt FS 1483 FIGURE 6 16 MIXTURE NEEDLE INSPECTION GASOLINE 2 Install idle mixture screw assembly Turninscrew until lightly seated and then out the number of turns specified in Table 6 2 Forcing the mixture adjustment ACAUTION screws fight will damage the needle and seat Turn in only until light tension is felt 3 Install needie valve and seat fuel bowl gasket and float assembly Make sure that all clips and springs are properly placed and that the float moves freely without binding See Figure 6 17 FLOAT AXLE Sy BUOYANCY SPRING POSITION HOOK UNDER TANG ON FLOAT POSITION OF SPRING AFTER INSTALLATION FS 1610 FIGURE 6 17 FLOAT INSTALLATION 4 Invert the float and needle valve assembly and check float tevel by measuring between the float and gasket at the point shown in Figure 6 18 The full weight of the float should be resting on t
10. its 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 ahead gasket on the cylinder head and align the stud holes in the gasket with the stud holes in the cylinder head While holding the gasket against the cylinder head carefully install the cylinder head on the engine Do not attempt to slide the gasket over the studs without the cylinder head behind it or the gasket may tear 5 Place heads in position and follow head torque tightening sequence shown in Figure 9 2 Begin by tightening all nuts to 5 fi lbs 7 Nem Then tighten all nuts to 10 ft lbs 14 Nem etc until all nuts are tightened to the torque listed under Torque Speci fications in Section 4 LEFT CYLINDER RIGHT CYLINDER M 1479 FIGURE 9 2 CYLINDER HEAD TIGHTENING SEQUENCE Power 9 1 Redistribution or publication of this document Generation by any means is strictly prohibited am om Asbestos gaskets contain fibers AWARNING that when airborne harm your health Use a respirator when handling and install ing gaskets 6 After the head nuts have been tightened once itis necessary to tighten each head nui to the specified torque a second time Follow the same sequence shown in Figure 9 2 Failure to re torque could result
11. nect run stop and battery charging functions The primary components of the PC board include three relays one power rectifier two diodes one capacitor five resistors and a five ampere fuse The only ser viceable component is the fuse which is removable from the front of the contro panel Connections to the PC board are made through an eight pin connec tor P1 mounted on the board and through the four lead wiring harness The PC board assembly mounts on the back of the control panel The PC board assembly is designed so that it will not be damaged by reversed battery polarity or by a short R6 CHARGE RESISTOR MOUNTS BEHIND LEFT CYLINDER Pi TO R6 2 Pl 2 TO Ki S AN Pi 3 TO IGN COIL Bs P2 PI 4 TO LOPKO PI 5 TO CR4 PI 6 TO KI 8 Pl 7 TO TERMINAL TAB PI TO TERMINAL TAB SC 1522 FIGURE 7 1 NHE CONTROL Power 7 1 Generation Redistribution or publication of this document by any means is strictly prohibited R6 TO REMOTE SWITCH S1 Start Run Stop switch 2 Low oil pressure cut out switch 3 Breaker points CR1 Power rectifier CR4 Field rectifier F1 Fuse Bi Starter Gi Generator START SOLENOID IGNITION COIL P1 T1 Pi DoR 4 SADR RECTIFIER STARTER MOTOR REMOTE SWITCH RUN LIGHT g TIME METER TOTALIZING BATTERY CONDITION METER Ghe eey tt a e y a a e o y oy y ES 1554 E1 Spark plug E2 Spark plug 3 Fuel pump R6 Battery charge
12. vents the set from restarting if the 51 switch is released from the Stop position Without ignition or fuel the engine stops As the generator output voltage drops the K2 generator relay also de energizes All components return to their de energized position following set shut down CR1 prevents the battery from discharging through the generator windings while the set is stopped NHE CONTROL TROUBLESHOOTING Use the troubleshooting guide to help jocate prob lems related to the NHE control Figures 7 1 and 7 3 show the location of most of the control components Refer to the wiring diagram in Figure 7 2 for location of all terminal connections The troubleshooting guide is divided into six sec tions After identifying the problem refer to the guide for the possible cause and the recommended correc tive action TROUBLESHOOTING THE NHE CONTROL Troubie Possible Cause Corrective Action Engine 1 If engine cranks at set but ta Check for continuity and Does Not not at remote control panel and correct if circuit is Crank fault is due to open a open circuit in remote control 1b Replace remote start b remote start switch faulty control switch 2 If engine cranks at remote 2a Check for continuity and control panel but not at set correct if circuit is open fault is due to 2b Replace 1 switch a open circuit in wiring between S1 switch and PC board or b faulty Si switch 3 Insufficient voltage for 3a Check con
13. It also prevents oil con tamination by removing moisture or gasoline vapors and other harmful blow by materials from the crank case These vapors are routed to the carburetor where they are mixed with incoming air and burned in the combustion chamber A sticky breather valve can cause oil leaks high oil compression rough idle reduced engine power and a rapid formation of sludge and varnish within the engine Power Generation 6 10 Redistribution or publication of this document by any means is strictly prohibited om om Crankcase Breather Service if the crankcase becomes pressurized as evidenced by oil leaks at the seals use the following procedures to service Remove the breather tube from the valve cover see Figure 6 10 Remove the valve cover pack spring washer reed valve and breather baffie Clean all parts in parts cleaning solvent Most parts cleaning solvents are AWARNING flammable and can cause severe personal injury if used improperly Follow the manu facturers recommendations when cleaning parts HEX HEAD CAPSCREW FLAT WASHER C 1101 FIGURE 6 10 CRANKCASE BREATHER The reed valve must be flat with no sign of a crease Assemble using a new gasket Do not overtighten valve cover capscrew Reed valve must be assembled as shown with washer on top and breather baffle on the bottom Over tightening the valve cover can ACAUTION cause an air leak and allow dirt to enter the engin
14. The air filter assembly consists of the air cleaner housing air filter air cleaner adapter and choke assembly See Figure 6 12 Disassembly Use the following procedures to remove and disassemble the air filter assembly 1 Remove the crankcase breather hose and air pre heater hose from the air cleaner housing 2 Remove the air cleaner housing center capscrew and lift off the housing and air filter 3 Remove the choke cover retaining nut and lift off the choke cover 4 Disconnect the choke jead wires at the choke terminals 5 Remove the three capscrews that secure the air cleaner adapter to the carburetor and lift off the adapier Note that choke linkage must be disen gaged from choke assembly as adapter Is removed 6 Remove the two capscrews that secure choke bracket to adapter and lift off choke assembly Assembly Reverse order of disassembly Use a new gasket between adapter and carburetor Carburetor and Intake Manifold Assembly The carburetor and intake manifold assembly con sists of the intake manifold choke pull off assembly air preheaters and carburetor See Figure 6 13 Disassembly Use the following procedures to remove and disassemble the carburetor and intake manifold assembly 1 Remove the air filter assembly as described in Air Filter Assembly in this section 2 Disconnect the fuel line and governor control linkage from the carburetor 3 Remove the intake manifold capscrews and lift
15. light time meter and battery condition meter e Opening the K3 9 16 contacts disconnects B from the K4 start relay causing it to de energize 7 3 Power _ Generation Redistribution or publication of this document by any means is strictly prohibited De energizing the K4 relay opens the K4 2 8 and K4 9 15 relay contacts Opening the K4 2 8 contacts has no effect since they are in parallel with the closed K3 9 15 contacts which connect B to the ignition coil and the fuel pump Opening the K4 9 15 contacts disconnects B from the K1 start solenoid De energizing the K1 start solenoid disconnects B from the starter motor which stops cranking When the S1 switch is placed in the RUN position the engine continues to run Relays K2 generator relay and K3 run relay are energized while relays K1 start solenoid and K4 start relay are de energized Generator voltage is rectified to DC by the CR1 power rectifier and supplied to the battery through the charge resistor R6 This charges the battery at a constant rate 1 ampere maximum during set operation Stopping Placing the Start Stop Run switch 81 in the Stop position grounds the K3 run relay This de energizes the K3 relay which opens the K3 2 8 and K3 9 15 relay contacts to disconnect B from the ignition coil fuel solenoid run light meters and K5 solenoid De energizing the K5 relay closes the K5 30 87A con tacts which holds the K3 relay grounded This pre
16. 00 in 76 20 mm 4 Ot 3 8 L 85 In 548 4 cm Lead Free or Regular LPG Propane Gasoline Liquid Withdrawal 6500 6300 120 54 2 52 5 60 Single 2 0 1 Amp 0 025 In 0 64 mm 0 016 In 0 41 mm 0 025 In 0 64 mm 0 021 In 0 53 mm 0 005 In 0 127 mm 0 013 In 0 330 mm 2 1 Redistribution or publication of this document by any means is strictly prohibited 2 2 Redistribution or publication of this document by any means is strictly prohibited Section 3 Models CYLINDERS AND PISTON ASSEMBLY Cylinder Bore Std Size honed Cylinder Taper Max Cylinder Out of Round Max Clearance in Cylinder Ring Gap Piston Ring 7 top Groove Width Piston Ring 2 Groove Width Piston Ring 3 Groove Width Piston Ring 1 Top Side Clearance Piston Pin Diameter Piston Pin Fit In Rod Connecting Rod Side Clearance Connecting Rod Bearing Clearance CRANKSHAFT AND CAMSHAFT Crankshaft Main Bearing Journal Diameter v Crankshaft Rod Journal Bearing Diameter Crankshaft Main Bearing Diameter sm d Power a Generation Dimensions Clearances 6 5 NHE AND 6 3 NHEL Dimensions not in parentheses are INCHES 3 5625 3 5635 90 488 90 513 mm 0 003 0 076 mm 0 003 0 076 mm 0 0070 0 0090 0 178 0 229 mm 0 0100 0 0200 0 254 0 508 mm 0 080 0 081 2 032 2 057 mm 0 080 0 081 2 032 2 057 mm 0 188 0 189 7 4 775 4 801 mm 0 002 0
17. 1 Make sure cutting tool is properly ground before using it 2 Besure top of engine block is smooth and deposit free 3 Clean base of boring bar before bar is set up 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 over size 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 too smooth of a finish can retard piston ring seating 1 Position block solidly for either vertical or horiz ontal honing Use either a drill press or heavy duty drill which operates at approximately 250 to 450 r min 2 Follow hone manufacturer s instructions for the use of oil or lubricant on stones Do not use lubri cants with a dry hone 3 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 4 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 unifor
18. 13 Generator Testing ce cece cree cree ew eeeecnees pare esa sewaeee mete sahiweesaee ane 8 13 SECTION 9 ENGINE BLOCK ASSEMBLY sesssssssrrurrnnrssoaranrossrneresrenrrurreorens 9 1 Generel EE E E E E E A E E E EE 9 1 Oil INGE and OGD ox cuaccanrettaehaaneeeesesaosenadeasueuss dance ecdeceeyasnecenesean cee 9 1 Cylinder EAS 25 sates beatetasceeevaes ENEE EEE E E eee ee ere 9 1 VANE SUSICON cxereeecec ci puieeee tenses Ga EAN SEERE EN T E EEEE 9 2 Gar COVEN occa cic cee oeee cose E EENE EAEE EREA ia i 9 6 GOVERNOR O cece cea EIEEE EEE een ere A E EEE EE T 9 6 Timing Gears and Cams errsssrirneeiaras sa krenner ease En aa A ena Eea 9 7 L brcalon OV SIOM antcoe ves ritenere EEEREN EE tee cl EE ERA 9 7 PISIOM ASS6MDI y oerrinne enrii a rae EEE E TE 9 8 Power s Redistribution or publication of this document Generation by any means is strictly prohibited Tabie of Contents continued TITLE PAGE BAE E a cawasee Ose ss0s04 404i bbe E sleet suuwenne lees dt vaaeesrcuacecueeeeteses 9 12 CVIINGEE BINOE srne irana esate PEELE EE EAEE sees eusecsesueoe enna 9 12 Boan E vine os tans A E E A E ANAE 9 15 BUES Ee E EE E TE S E E EE E E E E 9 16 SECTION T0 SERVICE CE GRIN teuicuaredediucee eww wen haces da whee AEE En ANIE 10 1 MONNI cad 4cecpaniaennnase EEEN este kt ohne se hares heres eee ene er eae oe 10 1 3 Eie ahela a P E E EEE E E E EE EE 10 1 WHE E E E TE E A S SETT r EEE E PEE EEE E T 10 7 Initial Start Adjustment
19. 31 Nuts Oil Pump 7 9 10 12 Rotor Through Bolt 45 55 61 75 Starter Mounting Screws 30 33 41 45 Stator Clamp Screws 10 12 11 16 Adapter to Engine 25 27 34 37 Mounting Screws Adapter to Generator 25 34 Mounting Screws Rear Vibration Isolator Center Screw 30 33 41 45 Flange to Drip 10 12 11 16 Tray Screws Front Vibration Isolator Flange to Oil 19 22 26 30 Base Screws Power i 4 1 Redistribution or publication of this document Generation by any means is strictly prohibited 4 2 Redistribution or publication of this document _by any means is strictly prohibited Section 5 Preparing to Service TROUBLESHOOTING Before servicing the generator set locate and isolate the problem using systematic troubleshooting pro cedures To aid servicing this manual divides the generator set into four logical groups and provides a separate section for each e Engine Primary Systems Control e Generator Engine Block Assembly This manual provides troubleshooting tables to help locate the cause of various malfunctions Some mal functions may have several causes Thus several likely problem areas may have to be investigated to isolate the source of the malfunction Because of the complexity of the product troubleshooting tables cannot list every malfunction and its cause In some situations the serviceperson will have to rely on experience and knowledge of the product to locate and correct the problem SP
20. 3410 0 3415 8 661 8 674 mm 0 344 0 346 8 738 8 788 mm 0 0010 0 0025 0 025 0 064 mm 0 0025 0 0040 0 064 0 102 mm 0 7475 0 7480 18 987 18 999 mm 0 7505 0 7515 19 063 19 088 mm 3 2 Redistribution or publication of this document by any means is strictly prohibited Dimensions Clearances continued Models Valve Lifter To Block Clearance Valve Seat Diameter Intake Valve Seat Diameter Exhaust Valve Seat Bore Diameter Intake Valve Seat Bore Diameter Exhaust Power _ Generation 6 5 NHE AND 6 3 NHEL 0 0015 0 0030 0 038 0 076 mm 1 5690 1 5700 39 853 39 878 mm 1 2550 1 2560 31 877 31 902 mm 1 5645 1 5655 39 738 39 764 mm 1 2510 1 2520 31 775 31 801 mm 3 3 Redistribution or publication of this document by any means is strictly prohibited 3 4 Redistribution or publication of this document by any means is strictly prohibited Section 4 Torque Specifications Models NHE AND NHEL TORQUE SPECIFICATIONS Use engine oil as a fubricant for all threads EXCEPT the spark plug and rotor through bolt threads FOOT POUNDS NEWTON METRES Cylinder Head Cold 18 20 24 27 Connecting Rod 27 29 37 39 Rear Bearing Plate 29 28 34 38 Fiywheel Mounting Screw 50 55 68 75 Oil Base 18 23 24 31 Gearcase Cover 8 10 11 14 Spark Plug 7 9 9 12 Exhaust Manifold 20 23 27 31 Intake Manifold 20 23 27 31 Other 3 8 Cylinder Block 18 23 24
21. 50 Hz Model 45 1 hertz 1350 30 r min Release governor linkage and check unit frequency and voltage Refer to Governor Adjustments in section 6 of service manual Perform necessary adjustments to achieve proper setting Mixture Screw Adjustments lf generator set voltage and frequency r min cannot be satisfactory adjusted and the generator set operation is erratic stop the generator set and review the following idle and main fuel mixture screw adjustments A Idle mixture screw adjustment Carefully remove screw adjustment limiter cap Using a screwdriver carefully turn the idle mix ture screw inward until lightly seated and then back out exactly one 1 full turn e Carefully replace screw adjustment limiter cap over screw head with limiter lever located at the LOW aititude position Take care not to change setting and confirm that limiter cap is tully seated over screw head B Main mixture screw adjustment Carefully remove screw adjustment limiter cap Turn the main mixture screw inward until lightly seated and then back out exactly one and one quarter 1 1 4 full turns out Carefully replace screw adjustment limiter cap over screw head with limiter lever located atthe LOW altitude position Take care notte change setting and confirm that limiter cap is fully seated over screw head Review Governor Adjustments in section 6 Add and remove a full load several times to make certain the g
22. Connect generator set positive battery cable to should be driven in about 1 10th of an inch 2 5 starter terminal Connect generator set negative mmm from the edge of the plastic retainer or so its terminal to generator set starting battery is evenly spaced from each side a Power 5 Redistribution or publication of this document Generation by any means is strictly prohibited Power Redistribution or publication of this document Generation by any means is strictly prohibited Supplement 940 102 Date 11 86 insert with Tite NHE NHEL Service Manual Number 940 0502 i PURPOSE This supplement reflects the following manual updates Page 1 for units equipped with a Nikki carburetor New throttle stop mixture adjustment and float setting in refer ence to like information found on pages 6 13 to 6 16 ait al Power r Redistribution or publication of this document Generation by any means is strictly prohibited om Nikki Carburetor Throttle Stop Fuel Mixture Adjustment and Float Setting Throttle Stop idle Adjust Connect a frequency meier to generator set Start the generator set and operate at no load Turn in the throttle stop screw idle adjust to contact the throttle lever tab While adjusting screw pull the governor linkage toward the engine and monitor the frequency meter Adjust the screw to obtain the follow ing setting 60 Hz Model 55 1 hertz 1650 30 r min
23. EIT locking washers Note that ground strap is installed between locking washers to insure a good electrical connection 10 Attach the special lifting plate see Figure 8 6 to the end of the stator housing using four 5 16 18 x 1 capscrews 11 Attach a hoist or other suitable lifting device to the lifting plate Carefully tiltthe set back until itis resting on the drip tray Remove lifting plate when complete i 12 Remove the piece of wire that is holding the brushes off the slip rings Check the brushes to verify that they are centered on the slip rings If brushes are not centered loosen the brush block mounting screws and adjust Retighten mounting screws when complete sana 13 Connect the B lead wire to the outboard brush terminal and the B lead wire to the inboard brush FIGURE 8 10 CHECKING BRUSH WEAR Power y 8 1 1 Redistribution or publication of this document p Generation by any means is strictly prohibited excessively worn and must be replaced Always replace the brush springs when installing new brushes to insure that proper tension is maintained Use the following procedure to replace the brushes 1 Disconnect the negative battery cable at the battery terminal 2 Remove the air cleaner cover and air cleaner filter element 3 Disconnect the B outboard and B inboard lead wires from the brush block terminals 4 Remove the brush block mounting screws and lift out the brush block 5 Remove brushes a
24. and close e Energizes the fuel solenoid valve E3 which opens to allow fuel to flow to the carburetor e Energizes the K5 stop relay to open the K5 contacts Energizes the Ki start solenoid to close the K1 contacts Opening the K5 stop relay contacts opens the circuit that holds the K3 run relay grounded This allows the K3 relay to energize when connected to B Closing the K1 start solenoid contacts connects B to the starter motor This energizes the starter motor which begins to crank the engine to initiate starting Starter Lock Qut Run When the engine starts the low oil pressure switch S2 closes to connect battery ground B to the K3 run relay As the engine comes up to speed AC out put voltage from the generator is supplied to the K2 generator relay This energizes the K2 relay which closes one set of contacts K2 2 5 that connects B to the K3 run relay This energizes the K3 relay which opens two sets of contacts and closes two sets of Power 7 9 Generation Redistribution or publication of this document by any means is strictly prohibited om PG BOARD ASSEMBLY CONTROL PANEL REAR VIEW START RUN STOP SWITCH CRS DIODE STOP GND STRT COMPONENT SIDE SC 1523 FIGURE 7 6 NHEL CONTROL PANEL ASSEMBLY contacts to produce the following control responses e Closing the K3 9 15 contacts which parallel the K4 2 8 contacts provides an alternate path way for supplying B to t
25. any means is strictly prohibited om Carburetor Overhaul Carburetor problems not corrected by mixture adjust ments may be caused by dirt in fuel passages or worn internal parts Under normal conditions the carbure tor should seldom require cleaning since LP gas va porizes complete before reaching the carburetor and leaves no residue However a bad fuel supply or inoperative fuel filter may allow dirt or oil to collect in the carburetor This may require that the carburetor be cleaned to restore satisfactory operation Overhauling the carburetor includes complete disas sembly thorough cleaning and replacement of worn parts Carburetor repair kits are available that supply new gaskets and replacement parts for the compo nents subject to wear Note the position of all components while removing to insure correct placement when reassembling Refer to Figure 6 26 for component designations Removal and Disassembly Remove the carburetor from the intake manifold as specified in Carburetor Air Filter and Intake Manifold Assembly in this sec tion Use the following procedure to disassemble the carburetor Mosi parts cleaning solvents are ACAUTION flammable and can cause severe personal injury if used improperly Follow the manu facturers recommendations when cleaning parts THROTTLE STOP SCREW IDLE ADJUSTMENT SCREW MAIN ADJUSTMENT SCREW Ly Cs THROTTLE 1 Remove the throttle stop collar and throttle stop le
26. bi meta strip to coil The coiling action of the bi metal strip turns the choke shaft and gradually opens the choke plate Heat from the element keeps the choke open while the engine is running The choke gets very hot during AWARNING normal operation and can cause severe burns if touched Do not remove choke cover while the set is operating Power Generation Redistribution or publication of this document by any means is strictly prohibited om HOUSING B1 METAL SPIRAL STRIP e PLASTIC COVER ELEMENT COVER XFS 1605 FIGURE 6 19 CHOKE ASSEMBLY If the engine starts but runs roughly and blows out the following procedures to adjust black smoke after a minute or two of operation the choke is set too rich If the engine staris but sputters 1 Remove the protective plastic choke cover see or stops before it warms up the choke is set too lean Figure 6 19 and loosen the heating element l cover screws for various ambient temperatures Stop the set and halfway open allow itto cool down before making adjustments Use 3 Slowly rotate cover counterclockwise CCW while tapping the carburetor choke lever and mak TABLE 6 3 ing the choke lever bounce Continue rotation until tapping the choke lever no longer makes it bounce This is the fully closed position and becomes the reference position CHOKE ADJUSTMENTS Ambient Air Rotation From Temperature Reference Mark Fully Closed 40 F 4 C 45 F 7 C
27. document by any means is strictly prohibited Trouble Engine Hunts or Surges High Oil Consumption Note New engines sometimes have high oil consumption during break in Low Oil Pressure Power Generation TROUBLESHOOTING ENGINE PRIMARY SYSTEMS Possible Cause Sticking or binding governor linkage Incorrect governor adjustment Faulty governor spring Incorrect fuel mixture due to a incorrectly adjusted fuel mixture screws bp incorrect float level or c dirt in carburetor 5 Governor mechanism worn excessively 6 Carburetor icing Gasoline sets only Oil viscosity too light or oil is diluted Crankcase breather valve is dirty or defective Oil leaks Excessive engine wear Light loading Oil viscosity too light or oil is diluted Low oil level Low oil pressure switch defective Faulty oil bypass valve Excessive engine wear or defective oil pump ta Ab 4c 5 Corrective Action Clean and lubricate governor linkage Adjust governor speed and Replace governor spring Replace governor spring Adjust carburetor main and idle adjustment screws Adjust carburetor float level Disassemble carburetor and clean all internal passages See Engine Block Assembly section In cold weather place air preheater in winter position Drain oil and refill with correct viscosity oil Clean crankcase breather and replace if de
28. for the breaker points and tappets CRANKSHAFT GEAR THESE MARKS MUST OR ALION WHEN INSTALL ING TIMING GEARS i ey TIMING GEAR REMOVAL AND INSTALLATION T 1029 FIGURE 9 15 Each timing gear is stamped with O near the 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 assem bly be sure that the thrust washer is properly in place behind the camshaft gear Then install the crankshaft retaining washer and lock ring LUBRICATION SYSTEM All generator set engines use an oil pump to providea constant flow of oil to the engine parts The oil supply collects in the oil base where it is picked up by the oil pump pick up cup A by pass valve is used to contro oil pressure Drain the oil before removing the oil base and always use a new gasket when replacing the oil base Oil Pump The oil pump Figure 9 16 is mounted on the front of the crankcase behind the gear cover and is driven by the crankshaft gear The inlet pipe and screen assembly is attached directly to the pump body A discharge passage in the cover of the pump regisiers with a drilled passage In the crankcase Parallel pas sages distribute oil to the front main bearing rear main bearing and pressure contral bypass valve OIL PUMP PICK UP CUP l LNG CRANKCASE FURNED M OIL PUMP ASSEMBLY ON LEFT SIDE aN SS LS 1109
29. make sure the exhaust pipes are not heating surrounding areas excessively If leaks are detected correct immediately Exhaust gas presents the hazard of AWARNING severe personal injury or death inspect exhaust system audibly and visually for leaks daily Repair leaks immediately EXHAUST GAS IS DEADLY Exhaust gases 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 Throbbing in Temples Muscular Twitching Vomiting Inability to Think Coherently Dizziness Nausea Headache Weakness and Sleepiness IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS GET OUT INTO THE FRESH AIR IMMEDIATELY If symptoms persist seek medical atten tion Shut down the unit and do not operate until it has been inspected and repaired Never sleep in vehicle with the generator set running unless the vehicle interior is equipped with an operating carbon monoxide detector Protection against carbon monoxide inhalation also includes proper exhaust system installation and visual and audible inspection of the complete exhaust system at the start of each generator set operation 1 RV om Power 10 1 Generation Redistribution or publication of this document by any means is strictly prohibited FUEL SYSTEM With the generator set operating inspect the fuel supply lines return lin
30. of cylinder bore and check A ae for a ridge Remove ridge see Figure 9 18 with a Ie ridge reamer before attempting piston removal Improper use of a ridge reamer can ACAUTION damage the cylinder bore Forcing the piston from the cylinder ACAUTION before reaming can damage the pis ton land or rings Remove wear ridge before remov ing the piston FIGURE 9 17 OIL BY PASS VALVE case Normally the valve begins to open about 30 psi 207 kPa The valve is non adjustable and normally needs no maintenance To determine if abnormal high or low oll pressure is caused by improper valve operation inspect as follows erie FIGURE 9 18 REMOVING WEAR RIDGE 1 Remove 3 8 24 x 1 in capscrew located behind gear cover and under governor arm 2 Ape Alt and plunger with a magnet or To remove the piston and connecting rod assemblies mag ale l turn the crankshaft until a piston is at the bottom of the 3 Determine proper valve operation by checking stroke Remove the nuts from the connecting rod bolts the spring and plunger according to the following measurements Lift the rod bearing cap from the rod and push the rod and piston assembly out the top of the cylinder with the Plunger Diameter 0 3105 to 0 3125 in handle end of a hammer Be careful not to scratch the 7 89 to 7 94 mm crankpin or the cylinder wail when removing these i parts Spring Free Length 1 00 inch 25 4 mm Mark each pi piston
31. or charge 2 Load connected to battery 2 Turn off load while set is turned off 3 Disconnect the negative 3a Refer to Generator section battery cable at the battery for testing and service and remove control iead P1 6 procedures from the battery positive 3b Replace control PC board terminal on the K1 start solenoid Connect a DC ammeter and 5 ampere fuse in series between the P1 6 lead D wire and the stud terminal on the K1 solenoid With set running the ammeter should read between 0 and 1 ampere if meter shows battery is discharging fault is due to a defective generator charge winding or b CR1 power rectifier open Power 7 13 Redistribution or publication of this document Generation by any means is strictly prohibited om Trouble Run Lamp Time Meter or Battery Condition Meter Does Not Operate Power _ Generation TROUBLESHOOTING THE NHEL CONTROL Possible Cause Open circuit between 1 terminal 6 or remote connector plug and terminal 6 on Start Run Stop switch Open circuit between ground 2 terminals on lamp or meters and terminal 1 on remote Start Run Stop switch If battery condition meter 3 works but time meter does not operate time meter is defective if time meter works but 4a battery condition meter does not operate verify that jumper Ab wire is connected between terminals 5 and 6 on remote start stop switch f jumper is in place connect a voltmete
32. publication of this document i ne by any means is strictly prohibited AWARNING Dropping the generator set 3 Lift the fork lift just so it makes contact with the creates the hazard of severe drip tray then just put a little upward pressure personal injury or death Make sure no one under the tray Verify the weight of the generator moves the vehicle during this procedure and that set supported by the forks before proceeding the procedure is performed very carefully and 4 Remove the bolts that secure the side support to only as instructed the drip tray and the underfloor bracket 5 Lift generator up slightly until safety catch on Use a fork lift truck to support the generator set tray at the points shown in Figure 5 4 Place a at peso aire Hi tray A wooden block on one fork so the set will remain and upward unti disengaged trom tray and aul underfloor bracket 6 Remove the side support to provide the clearance needed for lowering the set 7 Remove the safety catch from the center of each hinge assembly and then remove the U shaped hinge pin 8 Slowly lower the generator until it is clear of all obstructions and can be moved out from under AA the recreational vehicle WOOD BLOCK M 1601 FORK LIFT FIGURE 5 4 COMPLETE SET REMOVAL Power 9 6 Redistribution or publication of this document by any means is strictly prohibited Generation om Section 6 Engine Primary Systems INTRODUCTION The engine
33. screw out an additional 1 4 turn 4 Remove the load and verify that frequency is Start the engine and allow it to run for about 10 min utes Refer to Figure 6 14 for location of the adjust ment screws Use the following procedure to adjust Seopa N within 62 1 hertz Adjust governor speed adjustment nut if necessary to obtain required frequency 5 Turn the idle adjustment screw inward until volt age and frequency drop and engine begins to run rough or starts hunting Back out idle adjustment screw as required for smoothest operation with MAIN out hunting a 6 Pull the governor linkage toward the front of the set so that the throttie lever on the carburetor is resting against the throttle stop screw Adjust the stop screw to obtain a setting of 55 hertz and 100 FS 1608 4 5 volts 7 Release the governor linkage and observe the FIGURE 6 14 MIXTURE ADJUSTMENT SCREWS GASOLINE stability of the set Set the voltage and frequency ate Power a 6 14 Redistribution or publication of this document Generation by any means is strictly prohibited TABLE 6 2 CARBURETOR ADJUSTMENT SPECIFICATIONS NHE MIXTURE SETTINGS FLOAT MODEL LEVEL 4 16 1 32 in 1414 4 2441 4 1 6 0 8 mm Measure between bowl gasket and end of float and adjust the sensitivity of the governor as speci fied in the Governor section Add and remove a full load several times to make certain the set does not bog down or hu
34. set is to use a fork lift truck The generator set is heavy and can AWARNING cause severe personal injury if dropped during removal Use the recommended removal techniques and keep hands and feet clear While removing mounting bolts BARRIER DOOR MOUNTING HOLES COMPARTMENT FLOOR EXS 1121 FIGURE 5 1 TYPICAL CONVENTIONAL COMPARTMENT MOUNT INSTALLATION Power Generation Redistribution or publication of this document by any means is strictly prohibited om Removing Underfloor Mounted Set From RV When the generator set has been disconnected from the electrical exhaust and fuel systems the set may be partially removed for limited service or completely removed from the RV for major service The genera tor set is mounted on a Support tray which serves as the bottom of the underfloor housing The inner edge of the support tray is hinged to the rear panel assem bly The outer edge of the support tray is bolted to a support bracket A front and rear panel assembly serve as sides to complete the housing The generator set is completely suspended under neath the RV coach by the housing assembly To avoid dropping the set during removal follow the recommended set removal procedures AWARNING The generator set is heavy and can cause severe personal Injury if dropped during removal Use the recommended removal techniques and keep hands and feet clear while removing mounting bolts Partial Set Remova
35. steps 20A through 20C G 1177 FIGURE 8 7 STATOR ASSEMBLY REMOVAL CAPSCREW shown in Figure 8 7 Use two 5 16 18 x 1 capscrews to secure the puller to the housing Tighten puller center screw against rotor through bolt until nous ing lifts free of rotor and end bearing Remove puller when complete 15 Carefully lift the stator assembly straight up until it clears the rotor Careless handling of the stator ACAUTION can damage the insulation on the staior windings Do not brush the stator windings against the rotor as it Is lifted clear ROTOR TOOL 10 iN 254 mm 16 Place a3 8 inch allen wrench in the head of the rotor through bolt Using a rubber mallet sharply strike the allen wrench so the through bolt is driven in a counterclockwise viewed from generator end direction Several sharp taps should break loose the through bolt 17 Remove the rotor through bolt and in its place install the tool shown in Figure 8 8 Use a screwdriver to turn the rotor tool in a clockwise direction until it bottoms Install a 9 16 12 x 2 capscrew in the end of the rotor shaft and tighten until rotor breaks loose from crankshaft Remove capscrew from end of rotor when complete 18 Carefully lift the rotor assembly off the end of the engine crankshaft and remove rotor tool 19 Remove the brush block mounting screws and care G 1175 fully lift out the brush block assembly FIGURE 8 8 ROTOR TOOL a di Power 8 9 Redistribution
36. the intake mani fold as an assembly Refer to Fuel System in Section 6 for detailed removal procedures 5 Disconnect the lead wires from the charge resistor quick disconnect type connections the low oil pressure cutoff switch and the B terminal on the ignition coil 6 Remove the brush black cover and disconnect the B outboard and B inboard lead wires from the brush block terminals 7 Pull each brush outward from the holder and at the same time insert a piece of stiff wire into the smail hole in the end of the stator housing see Figure 8 5 Carefully guide the wire through the brush block and then release each brush Verify that each brush is held off the slip rings by the wire The brushes will be damaged dur ACAUTION ing disassembly if not held off the slip rings Make certain wire is in place before removing stator assembly B Remove the transformer cover and if the set is LP gas fueled disconnect the fuel line at the vaporizer coupling 9 Attach the special lifting plate see Figure 8 6 to the end of the stator housing using four 5 16 18 x 1 capscrews 10 Place a pad in front of the engine to cushion and protect the scroll Attach a hoist or other suitable lifting device to the lifting plate Lift the set as shown in Figure 8 6 until itis completely vertical and resting on the scroll Remove lifting plate when complete 11 Remove the capscrew and two EIT lock washers that secure the ground sirap to the dr
37. the low resistance of the transformer primary windings 2 milliohmmeter or equivalent must be used for accurate measure ments CR4 Bridge Rectifier Test The CR4 bridge rectifier can be tested using an ohm meter Remove the two AC leads and the positive and negative leads from the rectifier terminals Connect one of the test prods to one of the AC termi nals and the other test prod to the positive terminal Observe the reading on the ahmmeter and then reverse the test prod connections Observe the second reading and compare with the first reading A good rectifier will have a higher reading in one direction If both readings are the same the rectifier is defective and must be replaced Repeat test procedure with test prod connected to other AC terminal and with test prod connected to negative terminal Replace lead wires when test is complete At 77 F 25 C Power ps 8 1 5 Redistribution or publication of this document Generation by any means is strictly prohibited 8 16 Redistribution or publication of this document by any means is strictly prohibited Section 9 Engine Block Assembly GENERAL The engine block assembly includes the pistons and connecting rods crankshaft camshaft valves and lif ters cylinder heads lubrication system timing gears governor mechanism bearings and cylinder block Performing any major service on the block assembly will require that the generator set be r
38. 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 together Locate the expander gap 180 degrees from the ring gap FIGURE 9 26 INSTALLING PISTON Installing Piston in Cylinder When installing the pis ton assembly the raised lines witness marks see Figure 9 25 on the rods and caps must be aligned Also note thatthe connecting rod bolt is offset to one side af the cap When assembled on the crankshaft the thin side of the cap should be next to the cylinder block The rod and cap stamped 2 should be installed next to the bearing plate 1 Turn crankshaft to position rod bearing journal at bottom of its stroke 2 Lubricate piston assembly and inside of cylinder Compress rings with aring compressor as shown in Figure 9 26 Install bearing insert in rod 3 Position the piston and rod assembly in the cylinder block with the connecting rod oi hole toward the camshaft 4 Tap piston down into bore with handle end of hammer until connecting rod is seated on journal Check bearing clearance before proceeding to step 5 see Rod Bearing Clearance in this section 5 Lubricate the rod bearing journal and install the connecting rod cap Tighten connecting rod bolts to specified torque The bearing cap must be tapped Several times to properly align it with the con
39. 00000 soincrense is GND NOMINALNO XIXA B GREEN se LOAD VAC cal Lo l O BLACK NEUTRAL ee J B2 LOAD BLACK Due to the pos sibility of unit lead end identi fication being out of date with the wire diagram schematic of this supplement do not rely solely on lead markings by transformer when troubleshooting Instead check each fead from point to point to confirm that unit is wired properly T2 TRANSFORMER E3 FUEL PUMP OR FUEL SOLENOID Ti IGN COIL E12 SPARK PLUG S3 IGN POINTS CB1 2 CIRCUIT BREAKERS AC OUTPUT S2 SWITCH LOW OIL PRESSURE CR4 BRIDGE RECTIFIER S1 SWITCH START STOP CRS RECTIFIER USED WITH LPG ONLY RG RESISTOR BATTERY CHARGE ri CAPACITOR K5 RELAY USED WITH LPG ONLY BTI BATTERY 12V gt K1 START SOLENOID STARTER H1 CHOKE USED WITH GASOLINE ONLY A3 STANDARD REMOTE CONTROL G1 GENERATOR A2 DELUXE REMOTE CONTROL F1 FUSE Al CONTROL ASSY FIGURE 8 3 TYPICAL SCHEMATIC Power 8 4 Redistribution or publication of this document Generation by any means is strictly prohibited Power _ Generation BUS BAR T2 Tt 53 S2 S1 R KS KI H1 G1 Ft REMOTE PANELS STANDARD SEE NOTE WIRING DIAGRAM H T2 SCHEMATIC H2 REMOTE past RE 1 T ACAUTION bra ace i ue to the pos sibility of unit lead end identi fication being out of date with the wire diagram schematic of this supplement do not rely solely on lead markings b
40. 008 0 051 0 203 mm 0 7500 0 7502 19 05 19 06 mm 0 00005 0 00055 0 001 0 014 mm 0 0020 0 0160 0 051 0 406 mm 6 0005 0 0028 0 013 0 071 mm Dimensions noi in parentheses are INCHES 1 9992 2 0000 50 780 50 800 mm 1 6252 1 6260 41280 41300 2 0015 2 0040 50 838 50 902 mm 3 1 Redistribution or publication of this document by any means is strictly prohibited Dimensions Clearances continued Modeis Crankshaft Main Bearing Clearance Crankshaft End Play Camshaft Journal Diameter Camshaft Bearing Diameter Camshaft Bearing Clearance Camshaft End Play VALVES AND LIFTERS Valve Spring Free Length Valve Spring Compressed Length Valve Spring Tension Open Valve Spring Tension Closed Valve Face Angle Valve Seat Angle Valve Stem Diameter Intake Valve Stem Diameter Exhaust Valve Guide Diameter Valve Stem Clearance Intake Valve Stem Clearance Exhaust Valve Lifter Diameter Valve Lifter Bore Diameter Power _ Generation om 6 5 NHE AND 6 3 NHEL 0 0025 0 0038 0 064 0 097 mm 0 005 0 009 0 13 0 23 mm 1 3740 1 3745 34 900 34 912 mm 1 376 1 377 34 950 34 976 mm 0 0075 0 0030 0 038 0 076 mm 0 0030 0 0120 0 076 0 305 mm Dimensions not in parentheses are INCHES 1 6620 42 214 mm 1 3750 34 925 mm 71 79 lbs 32 36 kg 38 42 Ibs 17 19 kg 44 degrees 45 degrees 0 3425 0 3430 8 700 8 712 mm 0
41. E CLEARANCE ADJUSTMENT 3 To correct the valve clearance turn the adjusting screw as needed to obtain the right clearance The screw is self locking 6 Toadjust valves on the right cylinder turn engine one complete revolution and again line up mark on the flywheei and the TC mark on the gear cover Then follow adjustment procedure given for left cylinder 7 Replace all parts removed Tighten all screws securely Torque manifold bolts VT 1025 FIGURE 9 11 INSERTING NEW VALVE SEAT a Power as 9 5 Redistribution or publication of this document a Generation by any means is strictly prohibited GOVERNOR CUP BUSHING iN THE CUP GOVERNOR v N N N N N N N N N N N N N N N S S N N N N y N N N N N N S ROLL P f i GOVERNOR SHAFT Nill ROTATE NS GOVERNOR CUP GOVERNOR AN SO THAT ROLL PIN SHAFT YOKE FITS De bil SMOOTH SIDE IF FEELER WILL T D o OR ELAGIE OWARD CUP ENTER HOLE 1 2 IN 13 mm BALL HAS FALLEN OUT OIL SEAL T 1027 FIGURE 9 13 GEAR COVER ASSEMBLY GEAR COVER Remove the flywheel key and gear cover mounting screws Gently tap the gear cover with a plastic faced hammer to loosen it see Figure 9 13 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 ciock posi tion Use a smali amount of grease t
42. ECIAL TOOLS The following special tools may be required to ser vice the generator set Some of these tools can be purchased from Onan while others must be pur chased from outside suppliers Tool Catalog 900 0019 available from Onan Dealers or Distributors lists all tools available from Onan Engine Tools Torque wrench 0 175 Ft Lbs 0 240 Nem Feeler gauge Pressure gauge Spark plug gap gauge Carburetor adjustment wrench Points adjustment tool Fiywheel puller Snap ring pliers Gear puller with puller ring Cylinder ridge reamer Combination main and cam bearing remover Combination main and cam bearing driver Oil sea loader and driver Piston ring compressor Piston ring spreader Cylinder hone Valve seat cutter Valve spring compressor Valve lock replacer Valve seat driver Slide hammer Piston groove cleaner Outside micrometer set 0 4 In 1 102 mm Telescoping gauge set 0 5 6 In 12 154 mm Hole gauge 0 300 0 400 In 7 50 11 00 mm Plasti gage bearing clearance guide Generator and Control Tools Lead or dead blow hammer Battery hydrometer VOM multi tester Frequency meter Armature growler Jumper wires Load test panel SAFETY CONSIDERATIONS Always consider the safety aspects of any service procedure Generator sets present several hazards that the serviceperson must be aware of if the job is to be completed safely Read through the safety precau tions listed on the inside cover and famil
43. Figure 6 23 4 Wash all parts except gasket and seal in parts cleaning solvent Blow out solvent and dirt with low pressure compressed air Slosh the pump assembly in cleaning solvent blow dry and swab the inside of the plunger tube with a cloth wrapped around a stick If the plunger does not wash clean or has rough spots gently clean the surface with crocus cloth Most paris cleaning solvents AWARNING are flammable and can cause severe personal injury if used improperly Follow the manufacturers recommendations when cleaning parts 5 Insert plunger in tube buffer spring end first Check fit by slowly sliding the plunger back and forth in the tube it should move fully without any tendency to stick If a click cannot be heard as the plunger is slid from one end to the other the internal pump assembly is not functioning prop erly and the pump should be replaced PUMP ASSEMBLY PLUNGER RETURN SPRING TUBE CUP VALVE O RING SEAL WASHER RETAINER wed FIGURE 6 23 PLUNGER ASSEMBLY 6 Instali plunger spring cup valve O ring seal and washer Compress the spring and install the retainer with ends in the side holes of the tube 7 Check cover gasket and replace if deteriorated Place cover gasket in the bottom cover and install cover assembly on pump Twist cover on by hand and tighten securely with a 5 8 inch wrench Pump Test for units built June 1986 and after Test the fuel pump by checking the
44. Hazardous voit ages can flow from the generator set into the utility line This creates a potential for electrocution or property damage Connect only through an approved device and after building main switch is open Consult an electrician in regard to emergency power use GENERAL SAFETY PRECAUTIONS e Have a fire extinguisher nearby Maintain extinguisher prop and become familiar with its use ishers rated ABC by the NFPA are appropriate for all applications Con suit the local fire department for the correct type of extin guisher for various applications e Hot coolants under pressure can cause severe personal in jury DO NOT open a radiator pressure cap while the engine is running Stop the engine and carefully bleed the system pressure e Benzene and lead found in some gasoline have been iden tified by some state and federal agencies as causing cancer or reproductive toxicity When checking draining or adding gasoline take care not to ingest breathe the fumes or con tact gasoline e Used engine oils have been identified by some state or fed eral agencies as causing cancer or reproductive toxicity When checking or changing engine oil take care not to in gest breathe the fumes or contact used oil e Remove all unnecessary grease and oil fromthe unit Accu mulated grease and oil can cause overheating and engine damage which presents a potential fire hazard e DO NOT store anything in the generator compart
45. IGANON x lt 06s566006550004504 reir n eaenneeesenss Sea ue dew ge cee amawmonns 1 1 SECTION 2 SPECIFICATIONS 2 ye ceexceycatceen sce rire re n EAS EENE E 2 1 SECTION 3 DIMENSIONS AND CLEARANCES 2 2 2 cece eee eee eee ent e ee eeees 3 1 SECTION 4 TORQUE SPECIFICATIONS 2 ccc eee rece ce nseaccestacenatreerecccesteusteores 4 1 SECTION 5 PREPARING TO SERVICE 2 0 0c cece ccc c cece ener cece ener ne en een ebeenetoees 5 1 TIOUBISENOGUNG roresseriveriretibersa ki anias asad ane AE pen wanwaw bie cad 5 1 SPECIA TOO E ib cage cece cues chucauetyGbdetese crete des ercuem sab ayeneeteens nde E eae ees 5 1 Salet CONSICCIAUONG siiavecccuceseas sects pe eN ewes en dedauanseoteaeeeda E E 5 1 AGNOIGLOF Sot REMOVA wagnecns covoescues Earr EErEE Aa ee nstusepuree see reese 5 2 SECTION 6 ENGINE PRIMARY SYSTEMS cccee cece cece cere neta nest eeeeeeneeraes 6 1 WAT OGUCHION E conc tosee pananesveenaetewscewerencantuns EET E TE ETE 6 1 Troubleshooting Engine Primary Systems 00 ceca PT ee ee ee 6 1 EXWAUSEOVSICN lt cannscsseeeeyeronnya se eabeds bene em E EET ETTE E nrg 6 4 COON SYS eene EE E EEE eae ewateeeeaanewe EE REE EA 6 7 POON Systa e essensiaai nn RNEER RTEA 6 8 Crankc se Ventilation SYStGM siirerriiiridrars kipina in rN EEN RR 6 10 Cio 1469 raasde ee ee nr eee eee E ee ee ee ee EE 6 11 Fuel Svetem GasON NG cs conta rece rngy meres ow nie steninetnceyanews seus ese seedy enna nes 6 12 FUG System LP Gas nc rs
46. Loosen the conduit connector and pull the load wires and flexible conduit free of the junction box 7 Disconnect the muffler from the exhaust mani fold at the flange connection and disconnect any support brackets or hangers that connect the muffler to the set 8 On gasoline fueled sets turn off the fuel shutoff valve in the compartment and disconnect the fuel line at the fuel pump Securely plug the end of the fuel line to prevent leakage or accumulation of explosive gasoline vapor Fuel presents the hazard of fire AWARNING or explosion which can cause severe personal injury or death Make certain all fuel line openings are plugged to prevent gaso fine vapor from accumulating On LP Gas propane fueled sets disconnect the fuel line after purging at the solenoid valve and plug end of the fuel line to prevent entrance of dirt Removing Conventional Compartment Mounted Set From RV When the generator set has been disconnected from the electrical exhaust and fuel systems examine the set mounting and support system Locate all mount ing bolts and support members for the set In most installations the generator set drip tray will be bolted to the coach framework Depending on the installa tion the set may be removable from the side back or bottom Verify that the generator set is adequately supported before loosening any of the mounting bolts or sup port members The most satisfactory way to lift or move the generator
47. P Gas Fuel Systems LP gas liquid withdrawal fuel systems typically oper ate at pressures that range as high as 200 psi 1379 kPa when the ambient temperature is 110 F 43 3 C Because of the high pressures special pre cautions must be taken to avoid releasing large quan tities of highly flammable LP gas when servicing the fuel system Use the following procedure to purge the fuel system of LP gas before servicing any fuel sys tem components LP Gas Purging Procedure To purge the LP gas from the set fuel system close the shut off valve at the fuel tank and then start the generator set Allow the generator set to operate until it runs out of fuel Crank the set a few times after it stops to make sure the fuel system is completely purged of all LP gas fuel If the generator set cannot be operated move the RV coach to an outdoor location that is well ventilated and is away from fire or flame Disconnect both the vehicle negative battery cable and the generator set negative battery cable from their respective battery terminals Close the fuel shutoff valves at the fuel tank for both the generator set fuel supply system and the appliance stove heater etc fuel supply system In addition close the fuel shutoff valves at each appliance Fuel presents the hazard of fire or AWARNING explosion which can cause severe personal injury or death Ifaccidentally ignited Elimi nate all possible sources of ignition such as pilot l
48. R ROTORS RESISTANCE 4 72 in 120 mm 10 6 ohm 10 At 77 F 25 C STACK LENGTH To test for shorted windings set the ohnmmeter for the lowest scale Place the test prods on the slip rings as shown in Figure 8 12 A reading less than the value shown in Table 8 2 indicates shorted windings Replace a rotor with shorted windings with a new rotor SSAA NS YZ ee ae eb hh LZ ES 1553 FIGURE 8 13 TESTING ROTOR FOR OPENS OR SHOATS Stator Transformer Test The stator and transformer can be tested for grounded or open windings using an ohmmeter Testing for shorted windings requires a digital type ohmmeter than can read to within 0 01 ohms Figures 8 14 and 8 15 show the stator and trans former removed from the generator for testing How ever it is possible to tesi both components without removing them from the generator Remove the con trol panel and transformer cover to obtain access to the specified lead wires during testing Ground Test To test for grounds disconnect the following transformer and stator leads e Stator lead 1 from tap X2 Stator lead T1 from CBi e Stator lead T3 from CB2 e Stator lead 52 from CR4 AC1 e Stator lead B1 from R6 1 H1 1 lead wire e Stator lead B2 from ground tab e Transformer lead H1 from ground e Transformer lead H3 from ground e CR4 AC2 lead wire from tap X5 Insulate or position the lead wire ends so they are not touching the generator set housing Set t
49. and rod assembly so they can be returned to their GOAO aranea 2 60 2 Ibs 1 1 6 0 9 N respective cylinders after overhaul Keep connecting rod bearing when compressed to 0 500 inch 12 7 mm caps with their respective rods 4 Check the valve seat and clean away any accumu The pistons are fitted with two compression rings and lation of metal particles which could cause erratic one oil control ring Remove these rings from the pis valve action Verify that the valve seat is concent ton using a piston ring spreader as shown in Figure ric with the larger diameter valve bore 9 19 5 Clean plunger and spring in parts cleaning sol vent and install Mark each piston to make sure the rod will be assembled on the piston from which it was removed Power an 9 8 Redistribution or publication of this document Generation by any means is strictly prohibited Remove the piston pin retainer from each side and push the pin out Remove dirt and deposits from the piston pin surfaces with an approved cleaning solvent Clean the piston ring grooves with a groove cleaner or the end of a piston ring filed to a sharp point Figure 9 20 Care must be taken not to remove metal from the groove sides Using a caustic cleaning solvent or ACAUTION wire brush for cleaning pistons will cause piston damage Use only parts cleaning solvent When cleaning the connecting rods in solvent include the rod bore Blow out all passages with low pressure com
50. ansformer primary windings To isolate disconnect the transformer primary leads from the stator leads T2 from H2 or T4 from H4 Test each winding separately as specified in Table 8 ta locate the source of the open Replace the stator or transformer if test indicates an open winding To test for shorted windings use a digital type ohm meter that reads to within 0 01 ohms Disconnect the transformer and stator leads as specified in Ground Test in this section Connect the test prods see Figure 8 15 to the stator trans leads as specified in Table 8 4 A reading less than the value shown in Table 8 4 indi cates shorted windings If the low reading is between T1 H1 or T3 H3 the source of the short could be either the stator windings or the transformer windings To isolate disconnect the transformer primary leads from the stator T2 from H2 and T4 from H4 Test each winding separately as TABLE 8 4 RESISTANCE VALUES FOR STATORS AND TRANSFORMERS kW STACK TEST RESISTANCE LENGTH WINDING 40 STATOR TRANS 5 T1 to H1 0 240 ohm 4 61 IN T3 to H3 0 240 ohm 117 mm B1 to B2 0 049 ohm X1 to X6 0 578 ohm STATOR ONLY Ti to T2 0 240 ohm T3 to T4 0 240 ohm TRANS ONLY H4 to H3 0 009 ohm H2 to H1 0 009 ohm G 1172 1 FIGURE 8 15 TESTING STATOR AND TRANSFORMER FOR OPENS OR SHORTS specified in Table 8 4 to locate the short Replace the stator or transformer if test indicates a shorted winding Due to
51. ap Test coil and replace if necessary Test spark plug wires and replace if faulty Adjust carburetor main and idie adjustment screws Adjust carburetor float leve Disassemble carburetor and clean alt internal passages Locate leak and correct as required Drain fuel tank and refili with fresh fuel tn cold weather place air preheater in winter position Adjust breaker point gap Reset spark plug gap Adjust carburetor main and idle adjustment screws Adjust carburetor float level Disassemble carburetor and clean all internal passages See Engine Block Assembly Redistribution or publication of this document by any means Is strictly prohibited Trouble Engine Lacks Power Engine Black Exhaust Power _ Generation TROUBLESHOOTING ENGINE PRIMARY SYSTEMS Possible Cause 1 Faulty ignition due to a incorrect ignition timing b incorrect spark plug gap 2 Dirty air cleaner 3 Restricted fue flow due to a plugged fuel filter or b faulty fuel pump 4 incorrect fuel mixture due to a incorrect adjusted fuel mixture screws b incorrect float level or c dirt in carburetor Exhaust system blocked or 5 restricted Incorrect valve tappet 6 clearance Excessive engine wear or T damage to engine 8 Carburetor air preheater 8 set incorrectly Gasoline Sets Only Restricted airflow due to dirt or debris blocking air inl
52. b shoulder Push negative brush terminals over through bolt holes on brush endcap Insert positive brush stud into hole and torque to 25 30 Ib in 2 83 3 39 Nem Using a small screwdriver inserted into brush spring contact loop bend the spring back to allow each brush to be inserted into holder Be sure all brush wires are facing up Redistribution or publication of this document by any means is strictly prohibited 6 Ifthe brushes are at least 0 430 inch 10 9 mm long rest the brush springs against the sides of brushes to keep them clear during armature installation See Place magnetic housing over armature Use a nut driver over the end of shaft to hoid down armature and endcap Figure 7 10 Place spring washer and flat washer on shaft as Place washer on commutator end of shaft and put shown in Figure 8 armature into brush endcap Push the four brushes 11 Place mounting bracket on motor with exposed end toward commutator making sure springs are prop of sleeve bearing and through bolt lead ins to the erly positioned on brushes Recheck to be sure inside of motor The flat near one mounting hole spring is pushed all the way down on mounting tab should line up with the positive stud on end cap so Make sure all brush wires are clear of commutator through bolts will line up and that uninsulated portions of insulated wires do 12 Insert the through bolts and torque to 35 45 Ib in not touc
53. bed produces the following control responses e Fiashes the field to ensure that there is adequate residual magnetism to induce voltage build up e Energizes the ignition coi T1 soitcan produce an ignition spark when the breaker points open and close e Energizes the fuel pump E3 which begins pump ing fuel to the carburetor e Energizes the K1 start solenoid to close the K1 contacts Closing the K1 start solenoid contacts connects B to the starter motor This energizes the starter motor which begins to crank the engine to initiate starting Starter Lock Out Run When the engine starts the low oil pressure switch 52 closes to connect battery ground B to the K3 run relay As the engine comes up to speed AC out put voltage from the generator is supplied to the choke heater element H1 and to the K2 generator relay This activates the heating element which opens the choke and also energizes the K2 relay Energizing the K2 relay closes one set of contacts K2 2 5 that connect B to the K3 run relay This energizes the K3 relay which opens two sets of con tacts to produce the following control responses e Closing the K3 9 15 contacts which parallel the K4 2 8 contacts provides an alternate pathway for supplying B to the TT ignition coil and E3 fuel pump Opening the K3 1 8 contacts disconnects B CR4 positive terminal from the generator field wind _ ings Closing the K3 2 8 contacts connects B to run
54. between positive terminal on coil and ground Check for battery voltage when 71 is placed in the Start position lf the voltage is not present fault is due to a open circuit between coil and control b defective control PC board 1 Low oi pressure switch not closing due to a low oil level b open circuit between switch and contro c defective low oil pressure switch d low oil pressure 2 Output voltage from generator not being supplied to contro due to a defective charge resistor b open circuit in wiring between generator and control c defective bridge rectifier d no output voltage from generator ja 1b 1c 1d 2a 2b 26 2d Gorrective Action Tighten solenoid bracket mounting screw Replace K1 start solenoid Refer to Electric Starter section for test and service procedures Check for continuity and correct if circuit is open Replace control PC board Refer to Ignition System section section for test and service procedures Refer to Fuel System section for test and service procedures Gheck for continuity and correct correct if circuit is open Replace control PC board Check oil level and add oil if low Check for continuity and correct if circuit is open Replace low oil pressure switch Refer to Lubrication system section for test and service procedures Test R6 charge resistor 2 5 ohm and replace if defective Ch
55. bracket 5 Remove the four exhaust manifold screws and lift off the exhaust manifoid and the two manifold gaskets MUFFLER STHAP CUTOUT FRONT SET VIEW XEXS 1115 MUFFLER INLET FIGURE 6 1 EXHAUST SYSTEM CONVENTIONAL COMPARTMENT Power Generation 6 4 Redistribution or publication of this document by any means is strictly prohibited I set Is LP Gas fueled the fuel vaporizer and regulator are attached to the exhaust manifold Purge the fue system of LP gas fuel before disconnecting the fuel line at the vaporizer See FUEL SYSTEM LP GAS in this section for the recom mended purging procedures Assembly Obtain the required replacement parts and then proceed as indicated AWARNING Exhaust gas presents the hazard of severe personal injury or death To prevent exhaust leaks install all gaskets clamps straps and hardware as specified 1 Instali the exhaust manifold using new gaskets and tighten the four manifold screws to the speci fied torque 2 Install the 5 16 18 screw lock washer and nut that secure the manifotd outlet flange to the mani fold support bracket and tighten securely 3 Install the cooling system scroll and noise shield see Cooling System in this section Hf no other service is required install the generator set in the vehicle before completing the remaining steps 4 Install a new gasket between the exhaust mani fold and flange connector and secure flange con nector to ma
56. build up in the stator windings A portion of the AC current gener ated in the stator windings is rectitied to DC by the CR4 bridge rectifier The DC current is supplied to the rotating field windings to create the strong magnetic field required for generating the rated current The AC voltage build up stabilizes at approximately 128 volts when the engine reaches governed speed To prevent an excessive voltage drop when a load is applied to the generator a method for regulating the AC output voltage is required The voltage regulating trans former allows the generator to provide a stable AC out put voltage under varying load conditions Each trans former primary winding H1 H2 and H3 H4 is con nected in series with one of the stator AC output windings The full AC output current produced by the generator flows through these two primary windings Increasing or decreasing the current output from the transformer winding produces a corresponding increase or decrease in the primary current produced in the secondary winding The secondary winding is con nected in series with the circuit that supplies AC current for rectification to DC field current During operation adding load increases the current flow through the transformer primary windings which causes a corresponding increase in the current output from the STATOR HOUSING CONDUIT ELBOW transformer secondary winding This boosts the DC field current to a higher level to off
57. ceptible to warping and breakage 1 16 INCH 1 6 mm MINIMUM REFER TO SPECIFICATIONS FOR CORRECT DIAMETER ul J CHECK FOR BENT STEM fi 44 ft VT 1022 FIGURE 9 8 VALVE MARGIN Not all valves can be reconditioned A badly warped valve must be replaced because the excessive grinding required to make it seat correctly removes the margin To make a valve gas tight every trace of pitting must be removed from the valve face and seat Deeply pitted or cut valves must be replaced because the grinding removes the margin Valve seats should be ground with a 45 degree stone and the widih 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 it proper location Check each valve for a tight seat Make several marks at regular intervals across the valve face using machinists bluing Observe if the marks rub off uniformly when the valve is rotated part of a turn against the seat The valve seat should Power 9 3 Generation Redistribution or publication of this document by any means is strictly prohibited om contact the valve face evenly at all points The line of contact should be at the center of the valve face Valve Guide Replacement Worn vaive stem guides can be replaced irom inside the valve chamber a Seal is provided behind the intake valve guides only The smaller diameter of the tapered valve guides must face
58. ctumavnearscteaneanpasienesiwa snared eileeae scour ks E cae mne 6 19 BEG MON T CONTROLE 5 sadeucawesaciannacecotwaiwyues sc Seteneealtecnchng E aG 7 1 LPOGUCHOD coca E E Goes0g neers oh eke ae MiG E EST EEEE T 7 1 NHE Control DESCnOUON s 2cctccsnee se xiaeeectacesniiss ica sersantamstecule cieie E 7 1 NHE Control Op6iauGn s6cd c ax eccyenesvesccspeeiwentaeeennecdcnnen cs peste disdareawenenan 7 2 NHE Control Troubleshooting lt i s000s 6 iad seen woes dane osneyceeaceeycdeceurcayewedenserqueee 7 4 NREL Control DescrouGn ccs unt ceyenvencwsevesyaees es ENNEN E 7 8 NAEL Control Operation 6s lt lt 2sic doen dccewe bie des ee iaeducduar ah see see e ie yenesus cine wanes 7 9 NHEL Control Troubleshooting sssnersessesresresesrruessurrnerereresrrerserreress 7 11 SECTION 8 GENERATOR esenessusenernesessrssesessresreviresronennasnsssecsporreereas 8 1 Aaaale n ELESE os ee ck git eae N A nw ee 3d ere oa a ee cece E 8 1 Generator DESOT MION lt lt cotstantaeweawaeensesdece casei ers EEEE EEE TOR a r EERE 8 1 Generator Opela ON 2cncesis cos acucieesesteades eseusedusayeencet Olen EEEN 8 1 Generator Troubleshooting 6 lt lt 006 ss45 sees band AARET ENEE NATE clase teausan AN 8 3 Generator SEIVICG asec ries caw eerctwdenevonninescthwmaeyeeseven sear ees basin nani aaa 8 8 BriGhes ANd Sip RiNdS 2 2 c000s carn comets pariis aa certeatectwecseessnenepe es 8 11 Transtormer VolHage AGIUSIMGINS 61i0040is2easevsevendpe waver aoxeaweedbeseees taneGaeeee s 8
59. d cap screws to specified torque Tighten fuel vaporizer fit tings and check for leaks Carburetor Mixture Screw Adjustments LP gas carburetors have three adjustment screws that must be properiy set for satisfactory operation The throttle stop screw controls how much the throttle plate remains open when the throitle is pulled back to the closed position The idle adjustment screw con trols the fuel mixture when the set is operating at no load The main adjustment screw controls the fuel mixture when the set is operating at full load No other adjustments are required with an LP gas carburetor since there are no float or choke adjustments Mixture screws should not be adjusted until the igni tion system governor and other fuel system compo nents have been checked for correct operation If the carburetor is totally out of adjustment turn the mixture screws in until lightly seated For a preliminary adjust ment turn the main adjustment screw out 2 1 2 1 4 turns and the idle adjustment screw out 1 17 4 turn THROTTLE STOP SCREW IDLE ADJUSTMENT SCREW FIGURE 6 25 MIXTURE ADJUSTMENT SCREWS LP GAS MAIN ADJUSTMENT SCREW FS 1601 Forcing the mixture adjustment ACAUTION screws tight will damage the needle and seat Turn in only uniil light tension can be felt Start the engine and allow itto run for about 10 minutes at light load Refer to Figure 6 25 for location of the adjustment screws Use the following proced
60. ditications becomes the responsi bility of the person making the change Two basic exhaust systems are used with Emerald series generator sets Figure 6 1 shows a typical exhaust system for conventional compartment mount generator set Figure 6 2 shows a typical exhaust system for an underfloor mount generator set Separate sections cover the service procedures for each exhaust system L BRACKET SCROLL FLANGE CONNECTOR tly J N r Y ye Un y LAR LOCK WASHER O SCREW Compartment Mount Exhaust System Compartment mount exhaust systems consist of the exhaust manifold flange connector muffier muffler strap hanger clamps and tailpipe When service is required disassemble and reassemble as specified in the following steps Disassembly 1 Loosen the front muffler clamp muffler strap and tailpipe hanger and remove the muffler and tail pipe assembly see Figure 6 1 2 Remove the screws that secure the flange con nector to the exhaust manifold and remove the flange connector and asbestos gasket Completion of the remaining steps requires that the generator set be removed from the vehicle Refer to the Preparing to Service section for the set removal procedures 3 Remove the cooling system noise shield and scroll see Cooling System in this section to pro vide access to the exhaust manifold 4 Remove the screw that secures the exhaust mani fald outlet flange to the exhaust manifold support
61. dition of battery cranking due to and recharge or replace a Battery not charged or 3b Clean and tighten al b Terminal connections loose connections at battery or dirty K1 start solenoid and starter motor Short circuiting A WARNING the batiery cables can cause severe personal injury or death Disconnect the negative battery cable f at the battery terminal before servicing 4 Control fuse F1 is open 4 Replace fuse 5 ampere Power r 7 4 Redistribution or publication of this document Generation by any means is strictly prohibited Trouble Engine Does Not Crank cont Engine Cranks But Does Not Start Engine Starts But Stops When Start Switch is Released Power Generation TROUBLESHOOTING THE NHE CONTROL Possible Cause Connect a voltmeter between terminal S on the start solenoid and ground Check for battery voltage when 71 is placed in Start position If voltage is present fault is due to a K1 relay not grounded b defective K1 relay or c defective starter If voltage is not present as described in step 5 test fault is due to a open circuit between K1 relay and control PC board or b defective contro PC board Faulty ignition due to worn or fouled spark plugs worn ignition paints incorrect ignition timing or faulty plug wires Faulty fuel system due to sticking choke faulty fuel pump or carburetor mixture screws incorrectly adjusted Connect a voltmeter
62. dures completely observ ing all cautions and warnings before beginning any repair work The generator set installation must main tain compliance with the applicable recreational veh icle codes and standards The most critica areas of concern are the exhaust system fuel system electri cal wiring compartment construction and ventila tion system Improper servicing can create an unsafe installation that might cause serious personal injury or death or damage to the vehicle or equipment MODEL IDENTIFICATION Always supply the complete Mode Number Spec Number and Serial Number as shown on the genera tor set nameplate Figure 1 1 when contacting an Onan Dealer or Distributor This information is necessary to tdentify your generator set when order ing replacement parts Always use genuine Onan replacement parts ob tained from an authorized Onan Dealer or Distribu tor Universal type replacement parts usually in tended for automotive use often look similar but might not perform to Onan specifications Only genuine Onan replacement parts are designed and tested for specific applications to ensure reliabie ser vice and dependable operation NHE 1 A 26101 A PP rr ry Kilowatt rating Series identification NHE Gasoline fueled NHEL LPG fueled Voltage code 1 120 volts Starting method R Remote Factory code for designating modifications options or special features Specification lett
63. e Be careful not to distort the vaive cover when tightening GOVERNOR The governor controls engine speed which directly affects the voltage output and frequency of the generator An increase in engine speed will cause a corresponding increase in generator voltage and fre quency A decrease in engine speed will cause a corresponding decrease in generator voltage and Power Generation 6 11 frequency The governor maintains a constant engine speed under changing toad conditions so that generator voltage and frequency do not vary Governor Adjustments Before making governor adjustments run the unit about 10 minutes under light load to reach normai operating temperature If governor is completely out of adjustment make a preliminary adjustment at no load to first attain a safe voltage and speed operating range An accurate voltmeter and frequency meter should be connected to the generator in order to correctly adjust the governor A small speed drop not notice able without instruments will result in an objectionable voltage drop A binding in the bearings of the governor shaft inthe ball joint or in the carburetor throttle assembly will cause erratic governor action or alternate increase and decrease in speed hunting A lean carburetor adjustment can also cause hunting Springs tend to lose their calibrated tension through fatigue after long usage if the governor action is erratic after all adjustments are made replac
64. e Corrective Action Generator Generator overicaded due to Remove part of load and Overheats defective circuit breaker replace circuit breaker Airflow restricted due to Clear away all dirt or dirt or debris covering vent debris as required openings in stator housing Stator windings covered with Clean stator windings oi or dirt Open grounded or short Test each component for circuit in rotor stator or open grounded or shorted transformer windings and replace if defective ant al Power 5 8 7 Redistribution or publication of this document Generation by any means is strictly prohibited GENERATOR SERVICE This section covers generator disassembly and assem bly procedures Refer to Figures 8 1 and 8 2 to locate and identify the various generator components described in each sub section Generator Disassembly Use the following procedures to disassemble the generator 1 Drain the engine oil while the generator set ts still mounted in the vehicle 2 Remove the generator set from the vehicle and place it on a sturdy work bench Refer to Set Removal in Section 5 for the recommended set removal procedures 3 Remove the flywhee guard from scroll opening and the noise shield 4 The carburetor and intake manifold must be removed to provide clearance for lifting the genera tor stator assembly Disconect the choke heater lead wires throttle linkage fuel line crankcase breather hase and preheater tube Remove
65. e brush block cover when test is complete Rotor Test The rotor can be tested for grounded open or shorted windings using an ohmmeter Figures 8 12 and 8 13 show the rotor removed from the generator for testing However itis possible to test the rotor without removing it from the generator To obtain access to the slip rings remove the brush block cover Use a stiff wire to hold the brushes off the slip rings during testing Refer to Brushes and Slip Rings in this section for the proce dures to use for inserting the wire Ground Test To test for grounds set the ohmmeter for the highest resistance scale Touch one test prod to the rotor shaft and hold it there Touch the other test prod to one of the slip rings A reading less than one megohm indicates the rotor is grounded Replace a grounded rotor with a new rotor ES 1558 FIGURE 8 12 TESTING ROTOR FOR GROUNDS Open or Shorted Windings Test To test for open wind ings set the ohmmeter for the highest resistance scale Place test prods on the slip rings as shown in Figure 8 12 Ohmmeter should indicate continuity between slip rings A high resistance reading indicates a poor con nection or an open winding Check the connection between the slip rings and rotor lead wires Replace rotor if rotor winding is open l Power 8 13 Om Generation Redistribution or publication of this document by any means is strictly prohibited om TABLE 8 2 RESISTANCE VALUES FO
66. e cooling fins Assembly Cooling system assembly is the reverse of disassembly When installing the flywheel align the keyway in the flywheel with the woodruff key on the crankshaft Use non hardening sealer on the fly wheel capscrew threads and tighten to the specified torque Refer to Exhaust System in this section when installing the exhaust manifold muffler and tailpipe FLYWHEEL PULLER FLYWHEEL ens FLYWHEEL CAPSCREW 5 1000 FIGURE 6 5 FLYWHEEL PULLER ACAUTION Overheating can result in engine damage To avoid overheating never operate the generator set with any of the cool ing system components removed IGNITION SYSTEM The ignition system consists of the breaker points condenser ignition coi spark plugs and wiring For reliable generator set operation the complete igni tion system must be in good working order and prop erly adjusted Many generator set problems can be traced to an improperly maintained ignition system Refer to the following sections when servicing or making adjustments Breaker Points and Condenser The breaker points and condenser mount on top of the engine block A small plunger rides on an ignition cam at the end of the camshaft The plunger actuates the points which can open and close twice with every revolution of the camshaft Point opening is deter mined by the point gap setting The exact timing of the ignition spark is dependent on when the points open
67. e deglazing tool up and down in cylinder 10 to 12 complete strokes rapidly enough to obtain a crosshatch pattern as shown in Figure 9 30 Never use gasoline or commer ACAUTION cial cleaners to clean cylinder bores after deglazing or honing These solvents will not remove abrasives from the walls Abra sives not removed from engine will rapidly wear rings cylinder walls and bearing surfaces of all lubricated parts 4 Clean cylinder bore thoroughly with soap water and clean rags Continue cleaning until a clean white rag shows no discoloring when wiped through cylinder bore 9 14 Power Generation Redistribution or publication of this document by any means is strictly prohibited om AVOID THIS FINISH PRODUCE CROSS HATCH SCRATCHES FOR FAST RING SEATING CT 109 FIGURE 9 30 CROSSHATCHING BEARINGS Removal of the camshaft or crankshaft bearings requires complete disassembly of the engine Use a combination main and cam bearing removal tool and a press to drive out the bearings Support the casting to avoid distorting or damaging the bearing bores Camshaft Bearings Replacement camshaft bearings are precision type and do not require line reaming or line boring after installation Coat the bearing with lubricating oil Position the front bearing so the oil hole in the bear ing is aligned with the oil hole see Figure 9 31 in the block Position the rear bearing so the elongated slot is aligned wit
68. e the spring If this does notimprove operation the problem is probably within the gover nor mechanism Refer to Governor Cup Section 9 for service procedures Adjustments to the governor should be made in the following sequence 1 The carburetor fuel mixture screws must be cor rectly adjusted before governor adjustments are made If the carburetor needs adjusting refer to Mixture Screw Adjustments in this section before making any adjustmenis to the governor Touching hot exhaust pipes or AWARNING moving parts can result in severe personal injury Use extreme caution when making adjustments while the engine is running 2 Adjust the length of the governor linkage and check for binding or excessive looseness The length of the linkage connecting the governor arm to the throttle shaft assembly is adjusted by loosening the lock nut and rotating the ball joint see Figure 6 11 Adjust this length so that with the engine stopped and tension on the governor spring the stop on the throttle shaft assembly almost touches the stop on the side of the car buretor One more turn of the governor ball joint would allow the throttle shaft stop to touch the carburetor Tighten Jock nut 3 With the warmed up unit operating no no load adjust the speed adjustment nut to obtain 62 hertz and 127 5 4 5 volts for frequency and voltage Redistribution or publication of this document by any means is strictly prohibited 4 Check the fre
69. eck for continuity and correct if circuit is open Refer to Generator section for test and service procedures Refer to Generator section for test and service procedures Redistribution or publication of this document by any means is strictly prohibited Trouble Engine Starts But Stops When Start Switch is Released cont Engine Starts And Runs Then Stops Set Restarts Immediately or Set Restarts After Cooling Down Low Battery Power Generation om TROUBLESHOOTING THE NHE CONTROL Possible Cause Defective control PC board Fuel level is below generator set fuel pickup tube or oil level is low Faulty choke operation due to sticking choke linkage incorrect choke adjustment open circit in wiring between choke heater and generator or defective choke heater Vapor lock due to a high ambient air temperatures b faulty fuel pump Breaker points sticking Contaminated fuel Weak or discharged battery generator set charger will not recharge a battery that is in a very low state of charge Load connected to battery while set is turned off Disconnect the negative battery cable at the battery and remove control lead P1 6 from the battery positive terminal on the K1 start solenoid Connect a DC ammeter and 5 ampere fuse in series between the P1 6 lead wire and the stud terminal on the K1 solenoid With set running the ammeter s
70. ection 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 roundess as follows 1 Gheck cylinder bore for taper out of round and wear witha cylinder bore gauge telescope gauge or inside micrometer These measurements should be taken at four places top and bottom of piston ring travel parallel and perpendicular to axis of crankshaft 2 Record measurements taken at top and bottom of piston travel as follows see Figure 9 29 fp n see eee eres me it m m n To BOTTOM OF RING TRAVEL FIGURE 9 29 METHODS OF MEASURE CYLINDER BORE DIAMETER CT 1090 Measure and record as A the cylinder bore diameter parallel to crankshaft near the top of cylinder bore where greatest amount of wear Occurs Also measure and record as B cylinder bore diameter parallel to crankshaft at the bot tom of piston travel Measure and record as C cylinder bore diameter perpendicular to crankshaft near the top of cylinder bore where greatest amount of wear occurs Also measure and record as D cylinder bore diameter perpendicular to crankshaft at the bottom of piston travel Reading A subtracted from reading B and reading
71. emoved from the coach see Set Removal in Section 5 In addition to gain complete access to the block assembly the con trol generator and all primary engine systems must also be removed Refer to the previous sections for the disassembly and removai procedures OIL FILTER AND ADAPTER Open the oil drain valve and drain the crankcase oil Remove the filter see Figure 9 1 by turning counter clockwise with a filter wrench The low oil pressure cut off switch is installed in a threaded hole in the filter adapter and may be removed if required Loosen the two capscrews that secure the adapter to the engine block and remove the adapter and gasket Assembly is the reverse of disassembly Use a new adapter gasket and install so the two small oil holes are aligned with the oi holes in the block Gasket should be installed dry Coat the threads of each capscrew with non hardening sealer and tighten to recom mended torque LOW OIL PRESSURE SWITCH GASKET QIL FILTER 15 1111 FIGURE 9 1 OIL FILTER AND ADAPTER CYLINDER HEADS Remove the cylinder heads for cleaning when poor engine performance is noticed Use the following procedures to service 1 Use a 1 2 inch socket wrench to remove the cylinder head bolts or stud nuts and lift off the head Warpage can occur if the heads ACAUTION are removed while hot Wait until engine has cooled before removing heads 2 After removing heads clean out all carbon depos
72. emoved from the stator hous ing during disassembly use the following proce dures to install the transformer on the stator housing A Hold transformer in position for mounting on the siator housing Install the two mounting screws and tighten securely B Connectthe CR4 AC lead wire to the tranformer X2 tap and the S1 lead wire to the transformer X5 tap Note This is a preliminary connection that may require adjustment to obtain the correct generator output voltage See Transformer Volt age Adjustment section C Strip off 1 2 inch 13 mm of insulation from the ends of transformer primary leads H2 and H4 and from stator leads T2 and T4 D Twist each stator lead around the end of the corresponding transformer primary lead T2 to H2 and T4 to H4 Place a 6 uninsuiated barrel connector over the lead ends and crimp tightly using a 6 staking tool Wire nuts or other non crimp ACAUTION type connectors can loosen during set operation Use only the specified connector and crimping tool when connecting Stator leads to transformer primary tools E Slide a 2 1 2 inch 64 mm long piece of braided insulation over each connection as shown in Figure 8 9 Use a wire tie to hold BARREL CONNECTOR WIRE TIE ES 1552 FIGURE 8 9 BRAIDED INSULATION 8 10 Redistribution or publication of this document by any means is strictly prohibited insulation securely in place Pull each brush outward from the brush hold
73. enerator set does not bog down or hunt Stop genera tor set remove meter s and tools and close up genera tor set compartment Power Generation 10LE THROTTLE ADJUSTMENT STOP SCREW SCREW CAP IDLE ADJUST LEVER STOPS THROTTLE MAIN mina ADJUSTMENT one FS 1691 FIGURE 1 THROTTLE STOP AND FUEL MIXTURE ADJUSTMENT SCREWS Float Setting To adjust the float the carburetor must be removed from the generator set Refer to Carburetor Overhaul Removal Cleaning and Reassembly instruc tions in section 6 of the service manual Perform similar procedures to adjust the float by bend ing the tab and checking proper float position The Nikki carburetor float position is measured from the carbure tor housing to the far side bottom side of the float Proper float adjustment should reflect a measurement of 59 to 63 inch 15 to 16 mm 0 59 0 63 IN 15 16 mm TO ADJUST __ FLOAT J ey a a E oe A BOWL FLANGE GASKET TAS CONTACTING HEAD OF PIN WITH FULL WEIGHT OF FLOAT COMPRESSING INLET VALVE SPRING FS 1611 FIGURE 2 FLOAT LEVEL Redistribution or publication of this document by any means is strictly prohibited Table of Contents TITLE PAGE SAFETY PRECAUTIONS weiextucacuseeessa0 9 Anode heeasess ce cuwee enero Asie Inside Front Cover SECTION 1 INTRODUGTION aocieess ctxaneedencunse seseiaeeaedtiaeedisdstsew sed ees uses 1 1 Abou This MaM a arrn EEEE EEr A R AA 1 1 Model IGGNtI
74. er terminal Install brush block cover and tighten cover mounting screws 3 Siis lii i 14 Connect the appropriate lead wires to the charge and at the same time insert a stiff piece of wire resistor low oil pressure cut off switch and igni through the small holes in the base of the holder tion coil B terminal The wire holds the brushes off the slip rings dur f ing assembly Install brush block in housing and 15 Place new intake manifold gaskets on the engine tighten mounting screws block and install the carburetor and intake mani l fold assembly Tighten the intake manifold 4 Place the rotor in position for mounting on the screws to the specified torque Connect the pre end of the crankshaft and install rotor through heater tube crankcase breather hose fuel lines bolt Tighten through bolt just enough to hold throttle linkage and choke heater wires Refer to rotor in place Fuel System Section 6 for detailed assembly procedures ACAUTION i i racine ious baie 16 Install the noise shield flywheel guard and trans the stator assembly is installed can cause rotor former cover Shaft misalignment Follow recommended instal 17 Install the generator set In the vehicle and lation procedures to avoid any possibility of shaft securely fasten all mounting screws and hard misalignment ware Connect the fuel exhaust and electrical systems in reverse order of disassembly Refer to 5 Carefully lower the stator assemb
75. er Advances when the factory makes production modifications which affect all models OnonGenSet Model and Spec No Mid by Gnan Corp Minneapolis Mn 55432 USA Time Rating insul NEMA Class Amd 40 C For Recreational Vehicle Use Only Pour Usage Dans Les vehicules Recreatifs Type Fuel Made in USA 62 1360 M 1572 FIGURE 1 1 ONAN NAMEPLATE 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 sm Power 1 1 ora Generation Redistribution or publication of this document by any means is strictly prohibited Redistribution or publication of this document by any means is strictly prohibited Section 2 Specifications MODELS GENERAL Engine Design Generator Design Output Ratings Starting System Engine Speed Weight ENGINE DETAILS Displacement Compression Ratio Bore Stroke Oil Capacity With Filter Ventilation Free Area Fuel GENERATOR DETAILS Watts Volts Amps at 120 Volts Frequency Hertz Phase Wires Battery Charge fixed TUNE UP SPECS Check Spark Plug Gap Point Gap Valve Lash Intake Exhaust da Power om Generation NHE NHEL Four Cycle Air Cooled Two Cylinder Revolving Field Four Pole Unity Power Factor Automotive Type Starter 12 Volts 4800 r min 262 Ibs 119 kg 60 0 in 983 0 cm 7 0 1 3 56 In 90 42 mm 3
76. es filters and fittings for leaks Check any flexible sections for cuts cracks and abra sions and make sure they are not rubbing against anything that could cause breakage Leaking fuel creates a fire hazard ACAUTION which can result in severe personal injury or death if ignited if leaks are detected correct immediately CONTROL Stop and start the generator set several times at the set control and remote control to verify that the con trol functions properly Power Generation MECHANICAL Siop the generator set and inspect for leaking gaskets loose fasteners damaged components or interference problems Repair as required Inspect the generator set compartment and verify that there are no breaks or openings in the vapor proof wall that separates the compartment from the coach interior Seal openings as required Make sure all soundproof ing material is in place Redistribution or publication of this document by any means is strictly prohibited 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 Power Redistribution or publication of this document Generation by any means is strictly prohibited
77. es at each appliance Fuel presents the hazard of fire or AWARNING explosion which can cause severe personal injury or death Eliminate all possible sour ces of ignition such as pilot lights or sparking electri cal equipment before purging LP gas from the fuel system Provide adequate ventilation to dissipate LP gas as it is released Slightly open the fuel line flexible section at the solenoid valve just enough to allow the LP gas to slowly escape Don t open the fitting too much ora large quantity of gas will be released Disconnect the fuel supply hose from the carburetor and hold it clear of the set Press in and hold the primer button on the regulator to release LP gas from the set fuel system When no more gas can be heard escaping from the open end of the fuel supply hose reconnect the hose to the carburetor and proceed to the appropriate set removal section Disconnecting Set from RV Systems Disconnect the following items from the generator set 1 Disconnect the vehicle negative battery cable at the battery terminal 2 Disconnect the generator set negative battery cable at the battery terminal 3 Disconnect the generator set positive battery cable from the start solenoid 4 Disconnect the remote control wire plug from the generator set control 5 Disconnect the generator load wires at the RV electrical system junction box Tag the RV circuit wires if necessary for positive identification 6
78. ess to the cooling system and then pro ceed as indicated NOISE SHIELD CYLINDER AIR HOUSING FLYWHEEL FAN GUARD CS 1274 FIGURE 6 4 COOLING SYSTEM Redistribution or publication of this document by any means is strictly prohibited 1 Remove the capscrews that secure the noise shield see Figure 6 4 to the engine and lift off the noise shield 2 Remove the three nuts iocated along the lower edge of the scroll that fasten the flywheel guard to the scroll 3 Remove the capscrews that fasten the scroll to the backplate and lift away from the scroll 4 Remove the screws that fasten the cylinder air housings to the backplaie and cylinder heads and lift off the air housings 5 Loosen the flywhee capscrew and back it out several turns 6 Attach puller tool to the flywheel as shown in Figure 6 5 The tool has two jack screws that fit into the tapped holes in the flywheel 7 Tighten the puller center screw until the flywheel comes loose Remove the puller flywheel center screw and washer Inspect the flywheel and replace it if any air vanes are missing 8 Remove the lead from the low oil pressure cut off switch 9 Remove the exhaust manifold as described inthe Exhaust System section 10 Remove the capscrews that secure the backpiate to the engine and lift off the backplate 11 Use a brush or low pressure compressed air to remove any dirt or debris that may be lodged on the engin
79. et or outlet Dirt or oil covering engine cooling fins Incorrect ignition timing Lean fuel mixture due to Incorrectly adjusted fuel mixture screws incorrect float level or dirt in carburetor Gasoline sets only 1 Rich fuel mixture due to a dirty air cleaner b choke sticking c incorrectly adjusted fuel mixture screws d dirt in carburetor Gasoline sets only 6 2 3a 3b 4a 4b 4c Corrective Action Adjust breaker point gap Reset spark plug gap Replace air cleaner Clean fuel filter Test fuel pump and repair or replace if faulty Adjust carburetor main and and idle adjustment screws Adjust carburetor float level Disassemble carburetor and clean ail internal passages Locate and remove cause of blockage Adjust valve tappets see Engine Block Assembly section See Engine Block Assembly section in hot weather place air preheater in summer position Clear away any debris that may restrict airflow to set Do not use compartment for storage area Clean away all dirt and oil from engine cooling fins Adjust breaker point gap Adjust carburetor main and idle adjustment screws Adjust carburetor float level Disassemble carburetor and clean all internal passages Replace air cleaner Clean choke and choke linkage Adjust carburetor idle and main adjustment screws Disassemble carburetor and clean all internal passages Redistribution or publication of this
80. eutral conductors are white and the ground conductor is green The exit point for the wiring harness is near the voltage regulating transformer GENERATOR OPERATION Generator operation involves the control stator rotor voltage regulating transformer brushes and full wave bridge rectifier The schematic shown in Figure 8 3 is intended as an example to help follow the generator operating description Always refer to the specific sche matic that corresponds to the model and spec number of the generator set when troubleshooting problems When the Start Run Stop button is placed in the Start position the rotating field rotor is connected to battery Power Generation Redistribution or publication of this document by any means is strictly prohibited TO CHOXE 2 yee TO CR 4 q TO n CR4 JA QS hi CIRCUIT BREAKER CBi LOAD BLACK Jiu j BLOCK P lt S Pl STATOR HOUSING A 125 TO BRUSH BLOCK SI TO TRANSFORMER XG LS y2 To TRANSFORMER He 14 TO TRANSFORMER H4 STATOR CLAMPS 3 ROTOR NN SS 33 4 B2 10 TERMINAL TAB S2 TO CRS ACI STATOR TO R Tl TO C9 ROTOR THROUGH BOLT TO CHOKE 1 G 1171 FIGURE 8 1 GENERATOR oo 3 8 2 Redistribution or publication of this document Generation by any means is strictly prohibited positive B to ensure adequate residual magnetism to voltage build up As the engine starts and speed increases the rotating field induces a voltage
81. f linkage and slot in choke lever Correct alignment as required Measure distance between choke plate and bot tom of carburetor at the point indicated in Figure 6 21 If necessary bend diaphragm mounting bracket to obtain 0 39 to 0 43 inches 9 9 to 10 9 mm clearance 6 Move choke lever back and forth to check for free movement Verify that choke does not bind or stick 7 Remove vacuum supply from diaphragm and install filter assembly on carburetor Fuel Pump All gasoline fueled generator sets are equipped with an electric fuel pump All fuel pumps have an integral shut off valve that prevents fuel flow to the carburetor when the set is not in operation if the pump malfunctions or insufficient fuel delivery is suspected use the approp riate following procedure to test and repatr replace the pump Do not substitute automotive type AWARNING electric fuel pumps for standard Onan supplied electric pumps The output pressure is much higher and can cause carburetor flooding or fuel leakage creating a fire hazard on Pump Test for units built June 1986 and before Test the fuel pump by checking the pump outlet pressure Use the following procedure 1 Remove the fuel line from the pump outlet and install a pressure gauge 2 Press the START switch and hold it for several seconds unti pressure reading is constant 3 The pressure reading for a good pump should fail within 4 to 5 psi 27 5 to 34 4 kPa The press
82. fective Locate source of leak and repair as required See Engine Block Assembly section Don t run set at no load for long periods of time Drain oil and refill with correct viscosity oil Add oil as required Replace oil pressure switch see Engine Block Assembly section Inspect oil bypass valve clean or replace as required see Engine Block Assembly section See Engine Block Assembly section Redistribution or publication of this document by any means is strictly prohibited om EXHAUST SYSTEM The condition of the exhaust system is extremely critical on RV generator sets because of the possibil ity of exhaust gases entering the coach The exhaust system must be serviced immediately if inspection reveals leaking joints or connections loose fasteners or broken or damaged components Always replace worn components with new original equipment replacement parts Do not attempt to repair a broken exhaust pipe or manifold by welding and do not replace worn out components with parts that do not meet factory specifications Exhaust presents the hazard of AWARNING severe personal injury or death Modifying the exhaust system might allow poisonous exhaust gases to enter the coach Use only original equipment replacement parts when servicing the exhaust system Unauthorized modifications willaiso void the warranty and cancel the UL Listing CSA Certification Liability for injury or damages due to unauthorized mo
83. fied torque 2 Replace the noise shield and scroll refer to the Cooling System in this section H no other service is required install ihe generator set in the vehicle before completing the remaining steps 3 Place a U bolt type automotive muffler clamp in position on the exhaust manifold near elbow prior to installing muffler 4 Place muffler in position on set making certain that muffler inlet pipe overlaps exhaust manifold a minimum of 1 1 2 inches 88 mm 5 install the two 1 4 20 screws and lock washers that secure the muffler support bracket to the set and tighten muffler clamp 6 lf replacing the original tailpipe refer to the Tail pipe Recommendations section for selecting and locating the tailpipe Attach tailpipe to outlet end Power Generation Redistribution or publication of this document by any means is strictly prohibited om MUFFLER EXHAUST ELBOW 1 4 20 SCREWS EXS 1120 FIGURE 6 2 EXHAUST SYSTEM UNDERFLOOR MOUNT of muffler and secure using a 1 1 2 inch U bolt type automotive muffler clamp ONLY Support the tailpipe using a shock mounted sup port hanger with clamp Angular mounting of muffler A CAUTION and tallpipe hanger brackets can result in exhaust system damage since excessive vibration transfer to the vehicle is caused by angular mounting Mount muffler and tallpipe hanger brackets directly above component supported noi at an angie Run the generator set for f
84. h inside diameter of housing Uninsulated 3 96 5 09 Nem portions of wires must also not touch adjacent 43 Wipe dust from helix and gear and apply a light coat of GE Versilube 322 L on outside diameter of helix inside diameter of gear and unchamfered end of gear Place clutch and helix assembly on motor shaft with flats engaged in clutch hole ES 16117 FIGURE 7 RESTING BRUSH SPRING ON BRUSH SIDE 4 Power y Redistribution or publication of this document Generation by any means is strictly prohibited om WASHER SPRING WASHER itl FLAT WASHER ASSEMBLY 1 16 INCH WASHER SPRING RETURN COVER RETURN SPRING THROUGH BOLT N MAGNETIC Ter HOUSING ES 1613 FIGURE 8 STARTER ASSEMBLY 14 Hf Return Spring is Unassembied D Place spring cover over top of plastic retainer then the return spring on top of the retainer A Place 1 1 16 inch O D washer over end of E With washer placed over point of plastic shaft retainer push metal retainer into hole of plastic B With chamfered side of shaft hole up place plas retainer as far as it will go tic retainer on shaft and line up hole with hole in shaft 15 Mount starter on generator stator housing using capscrews lockwashers and nuts Tighten mount h a a C Support the plastic retainer with a vise or other ing screws to 30 33 lb ft 41 45 Nem solid surface Using a 5 32 to 1 8 inch nail set and hammer drive in a new roll pin The pin 16
85. h the breaker point plunger hole in the top of the block 7 32 IN ALIGN HOLE IN BEARING e 5 6mm ee er FROM WITH HOLE OUTSIDE IN BEARING BORE M1474 FIGURE 9 31 CAMSHAFT BEARINGS Use the combination main and cam bearing driver and a press to install the front and rear cam bearings Push in the bearings to the depth allowed by the flange on the driver Crankshaft Bearings New crankshaft main bearings are precision type which do not require fine reaming or line boring after installation They are available in standard size 0 002 0 010 0 020 or 0 030 inch undersize For putting in either the front or rear main bearing always align the oi hole s in the bearing with the oil Power Generation hole s in the bearing bore The oil passage must be at least 1 2 open Rear Bearing Use the combination main and cam bearing driver and a press to install the rear main bearing Push the bearing into the bearing plate from the inner side see Figure 9 32 to the depth allowed by the flange on the driver REAR BEARING END PLATE LOCK PIN va ALIGN BEARING OIL HOLES be WITH OF HOLES IN BEAR ING BORE THRUST WASHER SHIM BEARING PRECISION TYPE DO NOT LINE REAM OR SORE M 1475 FIGURE 9 32 REAR BEARING Front Bearing Locktite Bearing Mount is used when installing the front bearing see Figure 9 33 Use the toweletie furnished with the bearing kit to clean the outside of the bearing and the bearing bore in the
86. he needle valve and spring The correct distance is specified in Table 6 2 If the setting ts incorrect remove float and bend tab to adjust Bend the float only at the point indicated Attempting adjustments with ACAUTION the float assembly installed can damage the inlet needle and seat Remove float assembly before making adjustments BEND TAB TO ADJUST ee MEASURE THIS DISTANCE BOWL FLANGE GASKET TAB CONTACTING HEAD OF PIN WITH FULL WEIGHT OF FLOAT COMPRESSING INLET VALVE SPRING FS 1511 FIGURE 6 18 FLOAT LEVEL 5 Install float bowl and main mixture screw assem bly Turn screw in until lightly seated and then turn out the number of turns specified in Table 2 Forcing the mixture adjustment ACAUTION screws tight will damage the needie and seat Turn in only until light tension can be felt When carburetor is installed on set make final adjustments to mixture screws as described in Carburetor Mixture Screw Adjustments section Choke The choke consists of a bi metal spiral strip electric heating element and choke pull off diaphragm The bi metal coil is connected to the choke shaft and holds the choke plate nearly closed when the engine is cold When the engine starts vacuum from the intake manifold causes the pulloff diaphragm to pull in and partially open the choke As the engine con tinues to run electric current is supplied to the heat ing element Heat from the element causes the
87. he Tt ignition coil and fuel sole noid valve e Opening the K3 1 8 contacts disconnects B CR4 positive terminal from the generator fieid windings Closing the K3 2 8 connects B to the run light time meter and battery condition meter Opening the K3 9 16 contacts disconnects Bt from the K4 start relay causing it to de energize De energizing the K4 relay opens the K4 2 8 and K4 9 15 relay contacts Opening the K4 2 8 contacts has no effect since they are in parallel with the closed K3 9 15 contacts which connect B to the ignition coil and the fuel solenoid Opening the K4 9 15 con tacts disconnects B fram the K1 start solenoid De energizing the K1 start solenoid disconnects B from the starter motor which stops cranking When the S1 switch is placed in the RUN position the engine continues to run Relays K2 generator relay K3 run relay and K5 stop relay are energized while relays K1 start solenoid and K4 start relay are de energized Generator voltage is rectified to DC by the CR1 power rectifier and supplied to the battery through the charge resistor RG This charges the battery at a constant rate 1 ampere maximum dur ing set operation Stopping Placing the Start Stop Run switch 51 in the Stop position grounds the K3 run relay This de energizes the K3 relay which opens the K3 2 8 and K3 9 15 relay contacts to disconnect B from the ignition coil fuel solenoid run light meters and K5 sole
88. he ohmme ter for the highest resistance scale and then connect one test prod to the generator housing Touch the other test prod see Figure 8 14 to the leads speci fied in Table 8 3 A reading less than one megohm indicates a ground G 4172 FIGURE 8 14 TESTING STATOR AND TRANSFORMER FOR GROUNDS TABLE 8 3 GROUND TEST FOR STATORS AND TRANSFORMERS LOCATION Stator T3 Stator Bt Siator Transformer Power 8 14 Generation Redistribution or publication of this document by any means Is strictly prohibited lf the T1 T3 lead ts grounded the source of the ground could be either the stator windings or the transformer primary windings To isolate disconnect the trans former primary leads from the stator leads T2 from H2 and T4 from H4 Touch the test prod to T1 T3 H2 and H4 to identify the grounded component Replace a grounded stator or transformer with a new part Open or Shorted Windings To test for opens discon nect the transformer and stator leads as specified in the Ground Test section Set the ohmmeter for the lowest resistance scale and then connect the test prods see Figure 8 15 to the leads specified in Table 8 4 The ohmmeter should indicate continuity between lead ends A high resistance reading indicates an open winding If the open circuit is between T1 or T3 and one of the transformer primary lead wires H1 or H3 the source of the open could be either the stator windings or the tr
89. hould read between 0 and 1 ampere lf meter shows battery is discharging fault is due to a defective generator charge winding b CR1 power rectifier open 7 6 3 3a 3b 3a 3b Corrective Action Replace control PC board Check fuel and oil levels and refill as necessary Refer to Fuel System section for testing and service procedures Remove any objects or debris that may restrict airflow to and from the set Refer to Fuel System section for test and service procedures Replace breaker points Refill tank with fresh fuel Connect a separate battery charger to bring battery up to full charge Turn off load Refer to Generator section for testing and service procedures Replace control PC board Redistribution or publication of this document by any means is strictly prohibited Trouble Run Lamp Time Meter or Battery Condition Meter Does Not Operate Power Generation 1 TROUBLESHOOTING THE NHE CONTROL Possible Cause Open circuit between t terminal 6 or remote connector plug and terminal 6 on Start Run Stop switch Open circuit between ground 2 terminals on lamp or meters and terminal 1 on remote Start Run Stop switch If battery condition meter 3 works but time meter does not operate time meter is defective if time meter works but 4a battery condition meter does not operate verify that jumper 4b wire is connected be
90. hrough a dry rod pin bore as a result of its own weight replace the rod or bushing as required Piston Pin Inspection Replace piston pins that are cracked scored or out of round more than 0 002 inch 0 05 mm Bearing Inspection Inspect bearings for burrs breaks pitting and wear Replace bearing inserts that are scored have the overlay wiped out show fatigue failure or are badly scratched If bearings appear to be serviceable check them for proper clearance Piston Clearance Proper piston tolerances must be maintained for satisfactory operation Use a micrometer to measure the piston diameter at the point shown in Figure 9 23 When the cylinder bore is measured see Cylinder Block in this section subtract the piston diameter from the cylinder bore diameter to obtain the piston to cylinder wail clearance Refer to Dimenstons and Clearances in Section 3 for the recommended piston clearance Fitting Piston Rings Before installing new rings on the piston check the Power Generation 9 10 MEASURE Kx DIAMETER HERE CT 1063 FIGURE 9 23 PISTON CLEARANCE MEASUREMENT ring gap by placing each ring squarely in its cylinder at a position corresponding to the bottom of its travel Figure 9 24 The gap between the ends of the ring is given in Dimensions and Clearances in Section 3 The practice of filing ring ends to increase the end gap is not recommended If the ring end gap does not meet specificatio
91. iarize your self with the various hazards shown in Table 5 1 Once the hazards are known approach the job with a safety conscious attitude Being safety conscious is the most effective way to avoid injury to yourself or others Reduce the chance that an accident will occur by adopting the following safeguards Safeguards to Avoid Hazards Use Personal Protection When the situation calls for it protect your body by wearing the approp rlate safety equipment Protective clothing in cludes such items as safety shoes gloves safety glasses and hard hats Leave rings and jewelry off and don t wear loose clothing that might get caught on equipment Work to Reduce the Hazard The workshop area and all pieces of equipment used can contribute to reducing the hazard potential Keep guards and shields in place on equipment in good work ing condition Store flammable liquids in ap proved containers away from open flame Keep the workshop clean and well lighted and provide adequate ventilation Keep fire extinguishers and safety equipment nearby and be prepared to respond to an emergency Power 5 1 Generation Redistribution or publication of this document by any means is strictly prohibited om TABLE 5 1 HAZARDS AND THEIR SOURCE Fire and explosions Leading fuel Gasoline vapor LP gas vapor Hydrogen gas from charging battery Oily rags improperly stored Flammable liquids improperly stored Burns Hot exhaust p
92. ights or sparking electrical equipment before purg ing LP gas from the fuel system Provide adequate ventilation to dissipate LP gas as it is released CARBURETOR INTAKE MANIFOLD CARBURETOR Slightly open the fuel line flexible section at the sole noid valve just enough to allow the LP gas to slowly escape Don t open the fitting too much or a large quantity of gas will be released Disconnect the fuel supply hose from the carburetor and hold it clear of the set Press in and hold the primer button on the regulator to release LP gas from the set fuel system When no more gas can be heard escaping from the open end of the fuel supply hose reconnect the hose to the carburetor and proceed to the approp riate component service station Carburetor Air Filter and Intake Manifold Assembly The carburetor air filter and intake manifold assembly consists of the air cleaner housing air filter air cleaner adapter K5 relay assembly carburetor and intake manifold see Figure 6 24 Disassembly Use the following procedures to remove and disassemble the carburetor air filter and intake manifold assembly 1 Remove the crankcase breather hose from the air cleaner housing 2 Remove the air cleaner housing center capscrew and lift off the housing and air filter AIR CLEANER HOUSING AIR FILTER AIR CLEANER ADAPTER XFS 1612 FIGURE 6 24 CARBURETOR AIR FILTER AND INTAKE MANIFOLD ASSEMBLY 6 20 Redistribu
93. in a blown head gasket 7 Recheck torque before engine has run a total of 50 hours VALVE SYSTEM A properly functioning valve system is essential for goad engine performance All generator sets utilize an L head type valve design as shown in Figure 9 3 Access to the valve system can be obtained by remov ing the cylinder heads and the valve covers on top of the engine A valve spring compressor must be used to remove valves see Figure 9 4 from the cylinder block Use the following procedures to inspect and service the valve system NOTE SEE VALVE TAPPET CLEARANCES IN TEXT it VALVE SEAT INSERT VALVE GUIDE F je i a ed VALVE kd Py A A s Tay O r FIGURE 9 3 T 1018 VALVE SPRING COMPRESSOR FIGURE 9 4 Power Generation VALVE RETAINER VALVE SPRING VALVE ADJUSTING SCREW ne Pz 4 oo fe Lh LE ae m ae VALVE SPRING 3 A t r _ J __ _____ WASHER LOCK VT 1015 VALVE SYSTEM Inspection Valve Face Check the valve face for evidence of burn ing warpage out of round and carbon deposits Fig ure 9 5 VT 1017 FIGURE 9 5 VALVE FACE 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 Warpage occurs chiefly in the upper s
94. ings and a single secondary winding Each primary winding H1 H2 and H3 H4 is connected in series with one of the generator AC output windings The transformer secondary winding is connected in series with the field current circuit Taps on the secondary allow for field current adjustments The voltage regulating transformer mounts on the outside of the generator housing and is enclosed with a special cover The cover must be in place during operation for transformer cooling Field Current Rectifier CR4 The CR4 rectifier is a full wave bridge rectifier that is used to rectify a portion of the generator AC output voltage to DC for field excitation The positive and negative termi nals of the rectifier are connected to the generator brushes The rectifier mounts inside the generator set control and may be accessed by removing the control panel Brushes The brush block assembly consists of a single brush block with two brushes The brush block mounts inside the generator housing and can be accessed by removing the small plate at the rear of the housing Wiring Harness A separate wiring harness is provided for connecting the generator set to the RV electrical system All lead wires are stranded copper wire to withstand vibration The lead wires must be protected with flexible conduit which must be provided by the RV manufacturer A 3 4 inch conduit elbow is provided to facilitate installation The load wire conductors are black the n
95. ip pan 12 Remove the three vibration isolator center screws from the underside of the drip pan and liftaway from BRUSH BLOCK WIRE HOLE G 1178 FIGURE 8 5 BRUSH BLOCK the drip pan 13 Remove the four capscrews lock washers and nuts that secure the stator housing to the engine to generator adapter 14 Install a puller on the end of the stator housing as i R LIFTING PLATE CAPSCREW G 1176 FIGURE 8 6 GENERATOR SET LIFT Redistribution or publication of this document by any means is strictly prohibited d Power 8 8 om Generation 20 Use the following procedure to remove transformer from housing A Remove the braided insulating material from the CAPSCREW tee transformer primary lead wire T2 H2 and T4 H4 connections B Cut off the crimped barrel connectors and separate the transformer primary leads from the stator leads C Disconnect the lead wires from the transformer secondary taps D Remove the four screws that secure the trans former to the stator housing and lift off the trans former assembly The transformer air gap can be A CAUTION altered if the mounting bracket is removed from the transformer Do not loosen or remove any screws that pass through the transformer laminations 21 Use the following procedure to remove the stator from the stator housing A Remove stator lead wires from the transformer primary leads and secondary taps as described in
96. ipes Hot engine and generator surfaces Hot engine oil Electrical short in DC wiring Poisonous Gases Carbon monoxide from faulty exhaust LP gas leaking into coach interior Operating generator set where exhaust gases can accumulate e Develop Safe Work Habits Unsafe actions are identified as the cause of most accidents involv ing the use of tools and machines Be familiar with the equipment and know how to use it safely Use the correct tool for the job and check its condition before starting Observe the warnings and cautions in this manual and take special pre cautions when working around electrical equip ment Don t work alone if possible and don t take risks Be prepared if an accident does occur Numerous agencies such as the Red Cross and your local police and fire departments offer basic courses in first aid mouth to mouth resuscitation and fire control Take advantage of these offerings so you are ready to respond when an accident happens Learn to be Safety Conscious and make safe practices a part of your work routine GENERATOR SET REMOVAL Some service procedures will require that the genera tor set be removed from the coach While there are many variations generator set installations are generally classified as either conventional compart ment mount or under floor mount In a conventional compartment mount installation a special compart ment see Figure 5 1 is built into the coach to house the ge
97. isu ally and audibly for leaks daily at least every eight hours of running time Underfloor Mount Exhaust System Underfloor mount exhaust systems consist of the exhaust manifold muffler clamps hanger if re quired and tailpipe When service is required disas semble and reassemble as specified in the following sieps Disassembly 1 Loosen the muffler clamp at the muffler inlet see Figure 6 2 and remove the muffler support bracket screws 2 Loosen tailpipe hanger if used and remove the muffler and tailpipe assembly Completion of the remaining steps requires that the generator set be partially removed from the vehicle Refer to the Prepar ing to Service section for the set removal procedures 3 Remove the cooling system scroll and noise shield see Cooling System in this section to provide access to the exhaust manifold 4 Remove the four exhaust manifold screws and lift off the exhaust manifold and the two manifold gaskets lf set is LP Gas fueled the fue requlator vaporizer must be removed along with the exhaust manifold See FUEL SYSTEM LP Gas in this section for the vaporizer regulator removal and replacement procedures Assembly Exhaust gas presents the hazard of AWARNING severe personal injury or death To prevent exhaust leaks install all gaskets clamps Straps and hardware as specified 1 Install the exhaust manifold using new gaskeis and tighten the four manifold screws to the speci
98. ition System section for test and service procedures Refer to Fuel System section for test and service procedures Check for continuity and correct if circuit is open Repiace control PC board Check oil level and add oil if low Check for continuity and correct if circuit is open Replace low oil pressure switch Refer to Lubrication system section for test and service procedures Check for continuity and correct if circuit is open Replace K5 relay Test R6 charge resistor 2 5 ohm and replace if defective Check for continuity and correct if circuit is open Refer to Generator section for test and service procedures Replace control PC board Redistribution or publication of this document by any means is strictly prohibited TROUBLESHOOTING THE NHEL CONTROL Trouble Possible Cause Corrective Action Engine Starts Oil level is low Check fuel and oil levels And Runs Then and refill as necessary stops Set Restarts immediately or Dirty fuel restricting Clean fuel filter Refer Set Restarts fue filter causing to Fue System section for After Waiting filter to freeze up service procedures Several Minutes Breaker points sticking Repiace breaker points Contaminated fuel Refill tank with fresh fuel Low Battery 1 Weak or discharged battery 1 Connect a separate battery Generator set charger will charger to bring battery not recharge a battery that up to full charge is in a very low state
99. its from valve seat Select the proper size puller determined by the inside diameter of the valve seat The puller jaws must expand into the cylinder block at the point where the bottom of the vaive seat insert rests on the cylinder block see Figure 9 10 Using the new seat insert as a guide adjust the puller depth Position the puller on the valve seat and tighten hex nut Clamp cylinder block to a solid bench Attach slide hammer to puller Between blows with the slide hammer tighten the hex nut USE NEW VALVE SEAT TO ADJUST PULLER DEPTH C 1104 FIGURE 9 10 REMOVING VALVE SEAT Redistribution or publication of this document by any means is strictly prohibited Replacement After the old seat has been removed clean carbon or metal burrs from the seat insert recess Use a valve seat insert driver and a hammer to install the inserts Insert the pilot of the tool into the valve guide hole in the cylinder block Quickly drive in the valve seat Insert so that the insert goes evenly to the bottom of the recess tn the cylinder block Make certain that the valve seat insert rests solidly on the bottom of the recess around its complete circumference see Fig ure 9 11 The valve seat musi be staked to assure a tight fit and eliminate the danger of its loosening in the bore Refinish valve seat inserts before installing valves Insert valve seat staker in the cylinder block valve guide hole Rotate the staking tool unti
100. ive minutes and check entire exhaust system visually and audibly for leaks or excessive noise Clean spark arrester muffler every 100 hours of operation Remove 1 8 inch pipe plug in bottom of muffler and run set for five minutes Then replace pipe plug Inspect exhaust system visu ally and audibly for leaks daily at least every eight hours of running time Tailpipe Recommendations Tailpipes are supplied by the RV manufacturer and must meet several design specifications to ensure safe generator set operation If replacing the tailpipe make certain the replacement part is the same size and configuration as the original part Refer to the following guidelines for selecting and locating the tailpipe Exhaust gas presents the hazard of AWARNING severe personal injury or death Exhaust gases can enter fhe coach interior if the tailpipe is damaged missing or improperly installed Foilow the recommended exhaust system replace ment procedures to ensure safe operation e Use 1 3 8 inch ID 18 gauge rigid steel tubing for tailpipe Do not use flexible exhaust tailpipe since tt might break due to road shock and vibration e Install exhaust tailpipe at least 3 inches 76 mm away from the fuel tank and any combustible Power 6 6 Generation Redistribution or publication of this document by any means is strictly prohibited Pe om material If 3 inches 76 mm clearance cannot be maintained install suitab
101. l Fuel flows through the regulator only when the engine is cranking or operating and stops flowing when the engine is stopped FS 1598 FIGURE 6 28 LP GAS REGULATOR The regulator will normally require very little atten tion if the set is used on a regular basis and operated on clean high quality fuel Most regular malfunctions can be traced to the following two sources e Hardened diaphragms and seats due to extended periods of non operation a Dirt or foreign matter embedded on valves and valve seats Power Generation 6 23 SECONDARY SECONDARY VALVE DIAPHRAGM w PRIMARY DIAPHRAGM XFS 1600 FIGURE 6 29 REGULATOR ASSEMBLY A regulator that has been operated and then stored for any length of time may require rebuilding or replacement Diaphragms and gaskets tend to dry shrink and harden as the lighter petroleum ends evaporate Use the test procedure specified in the Regulator Test section to check regulator operation and then rebuild or replace as required Repair kits include detailed and illustrated installation instruct lons A regulator that has granules of foreign matter embedded on the secondary seat may cause incon sistent starting or idling These granules are seldom the result of insufficient filtration The foreign matter Redistribution or publication of this document by any means is strictly prohibited is dissolved in the liquid propane and forms into gra nutes as the fuel is
102. l Park the recreational vehicle on a level as possible surface surface must support floor jack wheels Then foliow these instructions very carefully If generator set will be left in the down tilted position for more than 30 minutes first drain the oil Oil in the engine cylinders can AWARNING cause engine damage during start ing attempts Oilcan enter the engine cylinders when the generator set Is in the lowered tilted position Do not leave the generator set in this position for more than 30 minutes if the oll has not been drained R is assumed that disconnecting the fuel exhaust etc If necessary has already been performed as described on the previous page 1 Put the vehicle in its park position lock the brakes and remove the ignition key Make sure no one moves the vehicle while performing this procedure Dropping the generator set AWARNING creates the hazard of severe personal injury or death Make sure no one moves the vehicle during this procedure and that procedure is performed very carefully and only as instructed 2 Usea floor jack similar to the one shown in Figure 5 3 and position the floor jack under the rein forcement ribs of the drip tray as shown 3 Raise the floor jack until it just makes contact with the drip tray then just puta little upward pressure under the drip tray 4 Remove the four bolts from the front support bracket and remove the support bracket itself FLOOR OF COACH
103. l a new spacer on the camshaft gear The governor cup must spin freely on the camshaft center pin without excessive looseness or wobble If the race surface of the cup is grooved or rough replace it with a new one The governor cup and flyballs are easily installed when the camshaft assembly is removed from the ON DRAWING WILL BE AS INDICATED ry enem aaO k S yii P Ci 5 it d T re ff Y a ar be a SNAP RING yT 1028 FIGURE 9 14 GOVERNOR CUP 9 6 Redistribution or publication of this document by any means is strictly prohibited aa Power orim Generation the specified amount Do not hammer the new pin into place or it will be damaged The camshaft center pin cannot be pulled outward nor removed without damage If the center pin extends out too far the cup will not hold the flyballs TIMING GEARS AND CAMSHAFT lf replacement of either the crankshaft gear or the camshaft gear becomes necessary it is recom mended that both gears be replaced 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 9 15 Tighten the screws alternately until both are tight Attach a gear puller to the puller ring and remove the gear The camshaft and gear are removed as an assembly Before removing the camshaft and gear assembly remove the cylinder head and valve assemblies Then remove the operating plunger
104. l bowl cover of the carburetor Carefully note position of float assembly paris then slide out retaining pin and remove the float assembly any springs or clips and the needle valve Unscrew and remove needle valve seat 2 6 Clean and Repair When the carburetor is completely disassembled clean and repair using the following procedure 1 Soak all metal components not replaced by repair kit in carburetor cleaner Do not soak non metal floats or other non metal parts Follow the cleaner manufacturer s recommendations AWARNING Most parts cleaning solvents A WARNING are flammable and can cause severe personal injury if used improperly Follow the manufacturers recommendations when cleaning parts Clean all carbon from the carburetor bore espe cially where the throttle choke plates seat Be careful not to plug the idle or main fuel parts Blow outall passages with compressed air Avoid using wire or other objects for cleaning that might increase the size of critical passages Check the condition of any needle valve not included in repair kit and replace if damaged Figure 6 16 Replace float if loaded with fuel or damaged Check the choke and throttle shafts for excessive play in their bore and replace if necessary Replace ald components with new parts included in repair kit Reassembly and Installation When the carburetor parts are Clean and dry reassemble using the follow ing procedure
105. l it drops to the Original stake marks Rotate staking too another 60 degrees 1 6 turn Using a lead hammer strike the staking tool asharp blow to wedge the new valve seat securely in place 1 oY CHECK THIS SURFACE FOR BURRS BEFORE INSERTING SEAT VALVE SEAT VALVE SEAT gna MRS N N 1 Aa rail v ne we anal re Piga nee as A ENT oe sh ee w A r AG ne eae aby i Ra J q Xj INSERT DRIVER 38 Tappet Adjustment The engine is equipped with adjustable valve tappets Adjust the valve clearance only when engine is at ambient temperature Proceed as follows 1 Remove all parts necessary to gain access to valve tappets 2 Remove spark plugs to make turning the engine easier 3 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 pres sure on the valve lifters Clearances are listed under Specifications in section 2 For each valve the gauge should just pass between the valve stem and valve tappet see Figure 9 12 EN y z VT 1026 FIGURE 9 12 VALV
106. l stators also have two lead wires S1 and S2 that are used with the voltage regulating transformer The stator mounts inside the generator housing and is held in position with four clamps and four caps crews A series of air intake openings in the end of the housing allow cool air to be drawn inside the housing for generator cooling The housing also pro vides a mounting point for the starter rear bearing brushes control fuel pump and voltage regulating transformer The complete stator and housing assembly bolts to the engine to generator adapter Rotor The 4 pole rotor provides the rotating magnetic field that is required for generating an AC voltage poten tial in the stator windings The DC current required for field excitation is supplied through two slip rings that mount on the rotor shaft The inner end of the rotor is connected directly to the engine crankshaft using a tapered seat shaft coupling and through bolt The slip ring end of the rotor is supported by a single bearing The bearing fits inside the generator housing bearing Cooling airflow for the generator is provided by a centifugal fan that mounts on the inner end of the rotor shaft The fan also serves as a mount for the stator ring gear Voltage Regulating Transformer The voltage regulating transformer see Figure 8 2 helps to provide stable generator output voltage under varying load conditions Voltage transformers are constructed with two primary wind
107. l ventilated MOVING PARTS CAN CAUSE SEVERE PERSONAL IN JURY OR DEATH e Before starting work on the generator set disconnect batter ies This will prevent accidental arcing e Keep your hands away from moving parts e Make sure that fasteners on the generator set are secure Tighten supports and clamps keep guards in position over fans drive beits etc e Do not wear loose clothing or jewelry while working on gen erator sets Loose clothing and jewelry can become caught in moving parts Jeweiry can short out electrical contacts and cause shock or buming if adjustment must be made while the unit is running use ex treme caution around hot manifolds moving parts etc ELECTRICAL SHOCK CAN CAUSE SEVERE PERSONAL INJURY OR DEATH Disconnect starting battery before removing protective shields or touching electrical equipment Use rubber insula tive mats placed on dry wood platforms over floors that are metal or concrete when around electrical equipment Do not wear damp clothing particularly wet shoes or allow skin sur faces to be damp when handling electrical equipment e Use extreme caution when working on electrical compo nents High voltages can cause injury or death Follow all state and local electrical codes Have ail electrical installations performed by a qualified licensed electrician Tag open switches to avoid accidental closure DO NOT CONNECT GENERATOR SET DIRECTLY TO ANY BUILDING ELECTRICAL SYSTEM
108. le heat shielding be tween tailpipe and combustible material or fuel tank to prevent excessive heating Do not terminate the exhaust tailpipe A Under a window door or any opening that might allow exhaust gases to enter the coach interior B Ahead of or under the generator compart ment air intake to prevent recirculation of exhaust gases Terminate tailpipe to the rear of the compartment air intake C Under the fuel tank fill spout to prevent spilled fuel from being ignited by a hot tailpipe D Under the vehicle to prevent exhaust gases from entering the coach interior through small openings in the underside of the vehicle Extend the tailpipe at least one inch 25 mm beyond the perimeter of the vehicle Direct exhaust gases down and away from the vehicle away from windows doors or compartment openings Donot connect the generator set exhaust tailpipe to the vehicle exhaust system Exhaust gases will be forced into the non running engine and might be released through the carburetor air intet Water vapor from the exhaust might also damage the non running engine COOLING SYSTEM A constant airflow is critical for engine and generator cooling to prevent excessive heat build up All Eme rald series generator sets use a Vacu Flo cooling system to provide the required airflow With Vacu Flo cooling a flywheel fan draws cool air in from the generator end of the compartment see Figure 6 3 The cool air passes ove
109. lean 1 Remove the four capscrews and lock washers that secure the filter bow to the filter body 2 Separate filter bowl from filter body and discard the O ring seal 3 Remove nut and washer from center stud and pull out the filter element FILTER ELEMENT FS 1614 FIGURE 6 31 FUEL FILTER lf filter element is clogged wash element in kero sene and blow dry with low pressure 35 psi 241 kPa compressed air Replace filter element if damaged Wipe the center stud magnet clean of any rust or scale particles that have collected Install clean filter element using two new gaskets and securely tighten center stud nut Place a new O ring in the filter bowl sealing groove Align reference mark on filter bowl with reference mark on filter body and install four capscrews and four lock washers Tighten capscrews to 56 to 74 in lbs 6 5 to 8 3 Nem torque When fuel system is pressurized check filter for leaks Power 6 24 Generation Redistribution or publication of this document by any means is strictly prohibited om ES 1553 FIGURE 6 32 SOLENOIDO VALVE Solenoid Valve The solenoid valve see Figure 6 32 provides a posi tive fuel shutoff whenever the generator sei is stopped The solenoid must be energized before fuel will flow to the regulator Service is iimited to replac ing the complete valve assembly if it does not operate properly The valve may be bench tested by connec
110. ly over the rotor Set Removal Section 5 and into position for assembly to the engine The 18 Fill crankcase with oil of the recommended clas rotor end bearing should fit snuggly into the sification and viscosity bearing bore hole ACAUTION Careless handling of the stator BRUSHES AND SLIP RINGS a can result in damage to the sta This section covers brush replacement and slip ring tor windings Do not brush the stator windings Service against the rotor as it is lowered into position Brush Replacement 6 Install the four nuts locking washers and cap Remove the brush block cover and inspect the screws that secure the stator housing to the brushes and brush holder for burn marks or other engine to generator adapter Tighten capscrews damage If the brushes appear to be in good condi to specified torque Note that each locking tion use a piece of wire modified as shown in Figure washer is installed under capscrew head 8 10 to check for excessive brush wear Insert the 7 Tighten the rotor through bolt to the specified wire into the hole above each brush Make sure the torque wire is resting on the brush and not on part of the 8 Hold the drip pan in position for mounting to the spring If the painted part of the wire is not brush is underside of the set and install the three vibration isolator center screws Tighten the rear genera tor end center screws to the specified torque 9 Secure ground strap to drip tray using a capscrew and two
111. m diameter move hone up and down all the way through cylinder bore 5 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 botiom at 90 degree angles 6 Crosshatch formed by the stones should form an included angle of 23 degrees This can be achieved by moving the rotating hone 250 to 450 r min up and down in cylinder bore about 40 times per minute f Clean cylinder bores thoroughly with soap water and clean rags A clean white rag should not become soiled on wall after cleaning is com plete Do not use a solvent or gasoline since they wash oil from the walis but leave metal particles 8 Dry crankcase and coat it with oil Deglazing Cylinder Bores Deglaze the 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 oi during piston ring break in 1 Wipe cylinder bores with a clean cloth which has been dipped in clean tight engine oil 2 Use a brush type deglazing tool with coated bris tle tips to produce a crosshatch pattern in the cylinder bore 3 The deglazing too should be driven by a slow speed drill Mov
112. measure resistance in the primary circuit connect one ohmmeter lead to the positive terminal and the other to the negative terminal on the coil The resistance should be between 3 87 and 4 73 ohms A high resistance value indi cates an open circuit or poor connection inside the coil and the coil should be replaced 4 To measure resistance in the secondary circuit connect the ohmmeter leads to the two high ten sion terminals see Figure 6 8 The resistance measured should be between 12 600 and 15 400 ohms A lower resistance value indicates a shorted secondary winding A high resistance value indicates the coil has excessive internal resistance or an open circuit Replace coil if not within specifications far a OHMMETER ES 1373 FIGURE 6 8 TESTING COIL SECONDARY Spark Plugs Remove and inspect the spark plugs at the intervals recommended in the Operators Manual A careful examination of the plug can often pinpoint the source of an engine problem The following covers some common spark plug conditions and the probable cause One Plug Carbon Fouled Check for an open ignition cable or low compression Black Soot Deposits Check for faulty choke operation overly rich fuel mixture or dirty air filter e Qil Fouled Check for faulty crankcase breather worn rings or worn valve guides e Burned or Overheated Check for leaking intake manifold gaskets lean fuel mixture or incorrect igniti
113. ment such as oil or gas cans oily rags chains wooden blocks portable propane cylinders etc A fire could result or the generator set operation cooling noise and vibration may be ad versely affected Keep the compariment floor clean and dry Do not work on this equipment when mentally or physically fatigued or after consuming any alcohol or drug that makes the operation of equipment unsafe RV 9 ar Power E Redistribution or publication of this document Generation by any means is strictly prohibited Onon Supplement 240 1039 Date 8 85 Insert with Tite NHE NHEL Service Manual Number 940 0502 This supplement includes latest starter repair informa tion for models NHE NHEL RV gensets ROLL PIN STARTER POSITIVE TERMINAL STARTER Edict THROUGH BOLTS FIGURE 1 1491 1667 STARTER ES 3608 ELECTRIC STARTER The following procedures caver the disassembly and testing of electric starter Disassembly Use the following pracedure to remove and disassem ble the starter 1 Disconnect the generator set negative battery cable from the set starting battery 2 Disconnect the generator set positive battery cable from the starter lug terminal SUPPORT PLASTIC RETAINER WITH A VISE OR OTHER SOLID SURFACE USE CARE NOT TO HAVE SPRING RETURN LEG BETWEEN THE PLASTIC RETAINER amp SUPPORT WHEN DAIVING OUT ROLL PIN aia to 1 8 NAIL SET 3 Remove the starter mounting sc
114. n or scored and cannot be smoothed out by pol ishing either the journals should be reground to use one of the standard undersize bearings or the crank shaft should be replaced Remove only as much metal as is required to restore the journal surface while maintaining the recommended bearing clear ance 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 Installation Lubricate the front and rear main bearings with engine oil Use oil or gear lubricant to hold the front thrust washer in place against the engine block The flat side of the thrust washer goes against the block Position the crankshaft so the crank throw is aligned with the notch at the rear of the crankcase and install the crankshaft Make sure the front thrust washer did not slip out of place during installation Place the oil seai loader on the oil seal guide and driver and insert into the rear bearing plate Remove the seal guide and driver leaving the loader in the bearing plate The loader prevents the seal from being cut on the crankshaft keyway during installa tion of the rear bearing plate Use oil or gear lubricant to hold the shim s and rear thrust washer in position on the rear bearing plate see Figure 9 32 The shim goes against the bearing plate and the flat surface of the thrust washer goes against the shim
115. nd brush springs from holder and replace with new parts 6 Pull each brush outward from the brush holder and at the same time insert see Figure 8 11 a Stiff wire through the small holes in the base of the SPRING BRUSH AN ANNY Y CML pled RL se WIRE 3 A A a a HOLDER G 1179 FIGURE 8 11 BRUSH REPLACEMENT 10 11 12 holder The wire holds the brushes off the slip rings during disassembly Install brush block in housing but do not tighten mounting screws Remove the wire that is holding the brushes off theslip rings by pushing it out through the hole in the end of the stator housing Adjust brush block so that brushes are centered on the slip rings and then tighten mounting screws Connect the B lead wire to the outboard brush terminal and the B lead wire to the inboard brush terminal Install brush block cover and tighten mounting SCrews Install air filter element and air cleaner cover Connect negative battery cable to battery terminal Slip Ring Service Remove the brush block cover and inspect the slip rings for grooves pits or other damage If the slip rings are not in good condition they may be refin ished using a commutator stone Use the following procedure to service l 2 Remove the air cleaner cover and air cleaner filter Disconnect the lead wires from the brush block terminals and then insulate the lead wire e
116. nds Tie the tead wires to one side to allow clear access to the slip rings Remove the brush block mounting screws and lift out the brush block Remove K1 S lead wire from the terminal onthe K1 start solenoid Connect a pushbutton type switch normally open in series between the Ki S lead wire and the S terminal on the K1 start solenoid Place a jumper wire between remote connector plug terminals 1 and 3 Press the pushbutton switch to crank the engine and then release switch as soon as the engine starts Hold commutator stone Onan tool 420 0259 against rotating slip rings until carbon is removed and all grooves or roughness is smoothed out Contact with rotating machin ery can cause severe personal injury Keep hands and fingers clear while ser vicing slip rings Remove jumper wire from remote connector plug Remove insulating materia from ends of brush lead wires and then install brush block Follow steps 5 through 10 in Brush Replacement in this section oe al Power 8 12 Redistribution or publication of this document Generation by any means is strictly prohibited TRANSFORMER VOLTAGE ADJUSTMENTS The generator output voltage may be adjusted by changing the connections to the transformer secondary taps This is necessary if the set voltage falls outside the recommended voltage range when operating at the specified frequency Use the following procedures to adjust the ge
117. necting rod Clear ance varies on the journal if this is not done Install the remaining pistons and rods in the same manner Crank the engine by hand to see that all bearings are free Rod Bearing Clearance 1 Mark all parts so they can be installed in their original positions and wipe all parts clean of any oil or grease 2 Place a piece of the correct size Plasti Gage across the full width of the bearing cap about 1 4 inch 6 mm off center 3 Install the bearing cap and tighten to the speci fied torque Do not rotate the crankshaft after the cap is in place 4 Remove the bearing cap and leave the flatiened Plasti Gage on the part to which it adheres Com pare the widest point of the flattened Plasti Gage with the graduations on the envelope see Figure 9 27 to determine the bearing clearance a a IOL rom ym OY othe HAS Pf sok M1 7I K4 wate t tdiul Pog to pge at FIGURE 9 27 MEASURING BEARING CLEARANCE Power 9 11 Generation Redistribution or publication of this document by any means is strictly prohibited om CRANKSHAFT To remove the crankshaft loosen the rear bearing plate screws and remove the bearing plate gasket thrust washer and shims Turn the crankshaft so the crankthrow is aligned with the notch in the rear open ing of the crankcase Carefully slide the crankshaft out of the crankcase Inspection Inspect the rod and main bearing journals it they are wor
118. nerator output voltage 1 Adjust the governor as specified in the Governor section before making adjustments to the trans former l 2 Check the generator voltage with the warmed up set operating at no load and 62 hertz frequency The nominal voltage should be 127 5 4 5 volts AC 3 Stop the setand adjust the transformer tap connec tions as shown in Table 8 1 to increase or decrease the voltage as required 4 Repeat the voltage check and continue to make adjustments until voltage is within range specified 5 Check the no load and full load voltage and fre quency as specified under Governor in Section 6 Voltage and frequency should stay within the limits shown in Table 8 1 GENERATOR TESTING This section covers the test procedures for the stator rotor transformer and CR4 bridge rectifier Field Voltage Test To check the field voltage remove the brush block cover and connect a DC voltmeter to the brush block terminals Connect the positive lead to the B outboard terminal and the negative lead to the B inboard terminal TABLE 8 1 TRANSFORMER TAP CONNECTIONS VOLTAGE ADJUSTMENT To Increase Voltage Standard Setting X1 X5 To Decrease X3 X6 Voltage X2 X6 X1 X6 Start the generator set and allow it to stabilize Measure the field voltage with no load applied and then with full load applied Both readings should fall within a range of 18 to 60 volts DC Remove test leads and replac
119. nerator set The compartment is constructed with a vapor tight barrier that seals off the generator set from the coach interior The generator set is usu ally fastened to the floor of the compartment which must b able to support the weight of the set Access to the compartment is through a door located in the exterior of the coach e Electrical shock AC Improper load connections Faulty RV wiring Faulty electrical appliance Faulty generator set wiring Rotating Machinery Flywheel fan guard not in place Slippery Surfaces Leaking or spilled oil Heavy Objects Removing generator set from RV Removing heavy components in an under floor mount installation see Figure 5 2 a special housing is used to suspend the generator set from the underside of the coach The housing bolts to special support members that are built into the coach framework The housing is mounted near the exterior of the coach and fimited access is pro vided through a door located in the exterior of the coach Because of the wide variety of generator set installa tions it is not possible to specify the exact removal procedures for each generator set If after examining the installation a satisfactory method for removing the set cannot be determined contact the RV coach manufacturer to obtain their recommendations before attempting to remove the set from the coach Generator sets are heavy and can AWARNING cause personal injury if drop
120. nifold using 5 16 18 inch screws lack washers and nuts 5 Attach the inlet of the muffler to the flange con nector using a U bolt type automotive muffler clamp ONLY Make certain that muffler inlet pipe overlaps flange connector a minimum of 1 1 2 inches 38 mm 6 Place muffler strap on muffler and position it below cutout in bottom of generator set drip tray Fasten strap to set L bracket using a 1 4 20 screw and lock washer Tighten strap around muffler using a 1 4 20 screw lock washer and nut 7 replacing the original tailpipe refer to Tailpipe Recommendations in this section for selecting and locating the tailpipe Attach tailpipe to outlet end of muffler and secure using a 1 1 2 inch U bolt type automatic muffler clamp ONLY 8 Support the tailpipe using a shock mounted sup port hanger with clamp Angular mounting of muffler and ACAUTION lailpipe hanger brackets can result in exhaust system damage since excessive vibration transfered to the vehicle is caused by angular mount ing Mount muffler and tailpipe hanger brackets directly above the component supported not at an angie 9 Run the generator set for five minutes and check entire exhaust system visually and audibly for leaks or excessive noise Correct as required 10 Clean spark arrester muffler every 100 hours of operation Remove 1 8 inch pipe plug in bottom of muffler and run set for five minutes Then replace pipe p ug Inspect exhaust system v
121. noid De energizing the K5 relay closes the K5 30 87A con tacts which holds the K3 relay grounded This pre vents the set from restarting if the S1 switch is released from the Stop position Without ignition or fuel the engine stops As the generator output voltage drops the K2 generator relay also de energizes All components return to their de energized position following set shut down CR1 prevents the battery from discharging through the generator windings while the set is stopped Redistribution or publication of this document by any means is strictly prohibited om Power _ 7 10 Generation om NHEL CONTROL TROUBLESHOOTING Use the troubleshooting guide to help locate prob lems related to the NHEL control Figures 7 4 and 7 6 show the location of most of the contro components Refer to the wiring diagram in Figure 7 5 for location tive action of all terminal connections Trouble Engine Does Not Crank Power Generation The troubleshooting guide is divided into six sec tions After identifying the problem refer to the guide for the possible cause and the recommended correc TROUBLESHOOTING THE NHEL CONTROL Possible Cause If engine cranks at set but 1a not at remote control panel fault is due to a open Circuit in remote control wiring b remote start switch faulty lf engine cranks at remote 2a control panel but not at set fault is due to 2b a open circ
122. non conductive line Do not use copper pip kA on flexible lines as copper will work harden and become e Be sure all fuel supplies have a positive shutoff valve GASOLINE AND LPG FUEL MAY BE ACCIDENTALLY IG NITED BY ELECTRICAL SPARKS presenting the hazard of fire or explosion which can resuit In severe personal in jury or death When installing the generator set Do not tie electrical wiring to fuel lines e Do not run electrical lines and fuel lines through the same compartment openings o Keep electrical and fuel lines as far apart as possible e Place a physical barrier between fuel lines and electrical lines wherever possibile e if electrical and fuel lines must pass through the same com partment opening make certain that they are physically by running them through individual channels or by passing each line through a separate piace of tubing e DO NOT SMOKE while servicing batteries Lead acid bat teries emit a highly explosive hydrogen gas that can be ig nited by electrical arcing or by smoking EXHAUST GASES ARE DEADLY e Never sleep in the vehicle with the generator set running un less vehicle is equipped with an operating carbon monoxide detector e Provide an adequate exhaust system to properly expel dis charged gases In exhaust system daily for leaks per the maintenance ule Ensure that exhaust manifolds are secure and not warped Do not use exhaust gases to heat a compartment e Be sure the unit is wel
123. ns check for the correctness of ring and bore sizes A cylinder bore that is 0 001 inch 0 03 mm undersize will reduce the end gap 0 003 inch 0 08 mm Standard size rings may be used on 0 005 inch 0 73 mm oversize pistons Rings that are 0 010 0 020 0 030 and 0 040 inch 0 25 0 51 0 76 and 1 02 mm oversize are to be used on corresponding oversize pistons Rings of the tapered type are usually marked TOP on one side or identified in some other manner Install these rings with the identification mark toward the closed end of the piston PISTON RING IN CYLINDER BORE 7 FEELER GAGE CT 1064 FIGURE 9 24 CHECKING RING GAP Redistribution or publication of this document by any means is strictly prohibited O WITNESS THIN SIDE OF CAP MARKS ROD 2 FIGURE 9 25 ROD CAP ALIGNMENT C779 Piston Assembly Installation Lubricate all parts with clean engine oil Position the piston on the connecting rod install the piston pin The piston pinis a full floating type and must be kept in place in the piston with two lock rings one at each side Install the two lock rings and ensure the lock rings are properly in place before installing the piston and connecting rod in the engine Install the rings on the piston beginning with the oil control ring Use a piston ring spreader to prevent twisting or excessive expansion of the ring Com pression rings are marked with a dot or ihe word top on one side of the ring
124. nt Carburetor Overhaul Carburetion problems not corrected by mixture or float adjustments are usually a result of gummed up fuel passages or worn internal parts The most effec tive solution is a compiete carburetor overhaul in general overhauling a carburetor consists of com plete disassembly a thorough cleaning and re placement of worn parts Carburetor repair kits are available that supply new gaskets and replacements for those parts most subject to wear 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 alf the instructions before beginning for a better understanding of the procedures involved Carburetor components are shown in Figure 6 15 IDLE CHOKE SHAFT ADJUSTMENT SCREW THROTTLE STOP SCREW CHOKE PLATE THROTTLE Lo een SHAFT COD pn FUEL INLET VALVE BUOYANCY SPRING FLOAT BOWL FIGURE 6 15 CARBURETOR OVERHAUL GASOLINE MAIN ADJUSTMENT SCREW ASSEMBLY XFS t604 1 Remove the air cleaner adapter and the automatic choke assembly Remove throttle and choke plate retaining screws then plates Pull out throttle and choke shafts being careful not to damage the teflon coating applied to some throttle shafts Remove main and idle mixture screw assemblies Separate the lower section of the carburetor fuel bowl from the upper section fue
125. ny means is strictly prohibited Pe Cleaning After removing pistons crankshaft cylinder heads etc inspect block for cracks and extreme wear If block is still serviceable prepare it for cleaning as fallows t 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 in a bath of commercial cleaning solu tion or hot soapy washing solution 3 Rinse block in clean hot water to remove cleaning solution inspection When rebuilding the engine thoroughly inspect block for any condition that would make it unfit for further use This inspection must be made after all parts have been removed and block has been tho roughly cleaned and dried 1 Make a thorough 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 machined 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 Insp
126. o assist in holding governor cup in position The rounded 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 engine If necessary the engine may be tilted up to install the cup and flyballs Put the flyballs between the spacer arms and install the cup on the center pin Lock the cup in place with the snap ring The camshaft center pin extends out 3 4 inch 19 mm from the end of the camshaft 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 If the dis tance is less the engine may race especially at no load Remove the center pin and press in a new pin 3 4 IN 19 mm WHEN GOVERNOR f P F Y 7 32 IN Refer to Oii Seals in this section if replacing the gear ASSEMBLED THE 5 6 mm CAMSHAFT cover oil seal DIMENSION SHOWN GEAR GOVERNOR CUP With the gear cover removed the governor cup can be taken off after removing the snap ring from the camshaft center pin Figure 9 14 Catch the flyballs while sliding the cup off Replace any flyball that is grooved or has a flat spot If the arms of the ball spacer are worn or otherwise damaged remove the spacer by splitting with a chisel Use a press to instal
127. off the carburetor air preheater Lift off the carbure tor and intake manifold as an assembly Power 6 12 Generation Redistribution or publication of this document by any means is strictly prohibited om CRANKCASE BREATHER TUBE CARBURETOR AIR BREATHER HOSE AIR CLEANER HOUSING AIR FILTER AIR CLEANER ADAPTER CHOKE COVER FS 1609 FIGURE 6 12 AIR FILTER ASSEMBLY 4 Remove the two intake manifold gaskets and plug the intake ports with a rag to prevent loose parts from accidentally entering ports 5 Remove the two capscrews that secure the car buretor and choke pull off assembly to the intake manifold Disengage the choke pull off linkage from the carburetor and carefully separate the carburetor from the intake manifold Assembly Reverse order of disassembly Use new gaskets between intake manifold and engine and between intake manifold and carburetor Do not use any sealer on gaskets Tighten intake manifold cap screws to specitied torque Carburetor Mixture Screw Adjustments The most common cause of poor carburetion is un satisfactory adjustment of the idle or main mixture adjustment screws Significant variation from the correct settings may result in serious engine trouble An overly rich mixture not only wastes fuel but can increase engine wear by washing the lubricant from the cylinder walls and diluting the crankcase oil An overly lean mixture results in a loss of power flat spot
128. ol PC board Redistribution or publication of this document by any means is strictly prohibited Trouble Engine Cranks But Does Not Start Engine Starts But Stops When Start Switch Is Released Power _ Generation om TROUBLESHOOTING THE NHEL CONTROL Possible Cause 1 Faulty ignition due to worn or fouled spark plugs worn ignition points incorrect ignition timing or faulty plug wires Faulty fuel system due to carburetor mixture screws incorrectly adjusted plugged fuel filter faulty regulator or faulty fuel solenoid Connect a voltmeter between positive terminal on coil and ground Check for battery voltage when 1 is placed in the Start position If voltage is not present fault is due to a open circuit between coil and control or b defective control PC board 1 Low oil pressure switch not closing due to a low oil pressure b open circuit between switch and control c defective low oil pressure switch d low oil pressure 2 K5 relay contacts not opening due to a K5 relay circuit open or b defective K5 relay 3 Output voliage from generator not being suppled to control due to a defective charge resistor b open circuit in wiring between generator and control c defective bridge rectifier or d no output voltage from generator 4 Defective contro PC board 7 12 1a 1b 1c 1d 2a 2b 3a 3b Corrective Action Refer to Ign
129. oltage is incorrect transformer is incorrectly connected or defective Open grounded or short circuit in rotor stator or transformer causes low AC output voltage Loose brush holder Worn generator end bearing Rotor and stator rubbing together due to a varnish lumps or b rotor misaligned with crankshaft Corrective Action Locate cause of overload and correct as required Reset breaker Check for continuity and correct if circuit is open Release brushes if jammed in holder Clean slip rings If dirty Test rectifier and replace if defective Test each component for open grounded or shorted windings and replace if defective Refer to Governor section Test CR4 rectifier and replace if defective Check length of brushes and replace if worn excessively Clean or replace slip rings Adjust tap connections on transformer secondary windings to obtain correct voltage Replace transformer if voltage cannot be corrected with adjustmenis Test each component for open grounded or shorted windings and replace if defective Tighten brush holder Replace end bearing Check for varnish jumps between rotor and stator and remove as required Follow specified assembly procedures to correct rotor to crankshaft alignment Redistribution or publication of this document by any means is strictly prohibited am Power 8 6 Ta Generation TROUBLESHOOTING THE GENERATOR Trouble Possibie Caus
130. olts and supporting members to verify that the generator set is properly mounted All fasteners should be tightened securely to prevent them from working loose when subjected to vib ration LUBRICATION If the engine oil was drained fillthe crankcase with oil of the recommended classification and viscosity Refer to the appropriate operator s manual for the specific recommendations and procedures WIRING Verify that all wiring connections are tight and hooked up properly Check each of the following e Load Wires Control Wires e Ground Strap Battery Cables INITIAL START ADJUSTMENTS Adjust the carburetor idie and adjustment screw and main adjustment screw as specified in Fuel System in Section 6 to allow starting Start the set and immediately adjust the governor speed adjustment nut to obtain a safe no load operat ing speed With no load applied listen for any unus ual sounds or vibrations When the choke is com pletely open adjust the carburetor and governor as specified in Fuel System Section OUTPUT CHECK Apply a full load to certify that the set will produce its full rated output Use a load test panel to apply a progressively greater load until full load is reached EXHAUST SYSTEM With the generator set operating inspect the entire exhaust system including the exhaust manifold muffler and exhaust pipe Visually and audibly check for leaks at all connections welds gaskets and joints and also
131. on timing Be sure plug is not in wrong heat range _ e Chipped Insulator Check for advanced timing Bend only side electrode when setting gap e Splash Fouled Check for accumulated com bustion chamber deposits See Cylinder Head in Section 6 Light Tan or Grey Deposits Normal plug color Replace spark plugs that show signs of fouling for electrode erosion with spark plugs of the recom mended type See Figure 6 9 on recommended method of checking plug gap ES 1374 FIGURE 6 9 CHECKING PLUG GAP Wiring ignition system wiring includes 1 One positive B wire which carries the low voltage current from the battery to the primary winding of the coil 2 One negative wire which carries low voltage to the points and condenser 3 Two high tension wires that carry the high voltage current from the secon dary winding of the coil to the spark plugs The spark plugs and coil secondary are all grounded to the engine making a complete circuit for the voltage back to the battery The ignition coil primary low voltage side is grounded when the breaker points close Check all low voltage wiring for loose connections and cuts or breaks in the insulation Clean all termi nals and connections and test for continuity with an ohmmeter Use a megger to check for breaks in the spark plug wire insulation CRANKCASE VENTILATION SYSTEM The crankcase breather prevents pressure from building up in the crankcase
132. or publication of this document Generation by any means is strictly prohibited B Cut off the wire ties that secure the stator lead wires to the inside of the housing Cut only wire ties not the tie supports C Remove the four stator clamps and capscrews D Carefully lift the stator straight up until it clears the stator housing Careless handling of the sta A CAUTION tor can damage the insulation on fhe stator windings Do not brush the windings against the housing as it is lifted clear Use the following procedures to assemble the generator If the stator was removed from the housing during disassembly use the following procedures to install the stator in the housing A Position the stator so the output leads are oriented as shown in Figure 8 1 then carefully lower the stator into the stator housing Careless handling of the sta ACAUTION tor can result in damage to the stator windings Do not brush the stator windings against the housing as it is lowered into position wa Install the four clamps and capscrews that secure the stator to the housing Tighten cap screws to specified torque C Route stator lead wires through holes in stator housing as specified in Figure 8 1 Fasten wir ing harness to inside of housing using wire ties D If transformer was not removed during dias sembly follow step 2c through 2e to connect stator output leads to transformer 2 Ifthe transformer was r
133. ped during removal Use adequate lifting devices to pro vide sufficient support for the set Keep hands and feet clear while lifting Special fuel handling procedures are required when removing an LP gas propane powered set The fuel system must be purged of LP gas before the set can be safely removed from the coach Follow the purg ing procedure described in the next section before attempting to remove an LP gas powered set If the generator set is powered by gasoline proceed to the appropriate set removal section LP Gas Propane Purging Procedure To purge the LP gas from the set fuel system close Power 5 2 Generation Redistribution or publication of this document by any means is strictly prohibited om the shut off valve at the fuel tank and then start the generator set Allow the generator set to operate until it runs out of fuel Crank the set a few times after it stops to make sure the fuel system is completely purged of all LP gas fuel If the generator set cannot be operated move the RV coach to an outdoor location that is well ventilated and is away from fire or flame Disconnect both the vehicle negative battery cable and the generator set negative battery cable from their respective battery terminals Close the fuel shutoff valves at the fuel tank for both the generator set fuel supply system and the appliance stove heater etc fuel supply sys tem In addition close the fuel shutoff valv
134. pressed air Inspection The following covers inspection procedures for pis tons and connecting rods CT 1089 Piston Inspection Inspect the pistons for fractures at the ring lands skirts and pin bosses Check for wear at FIGURE 9 19 REMOVING PISTON RINGS the ring lands using a new ring and feeler gauge as shown in Figure 9 21 Replace the piston when the side clearance of the top compression ring reaches 0 008 inch 0 20 mm j _ f CT 1061 CT 1060 FIGURE 9 20 CLEANING RING GROOVES FIGURE 9 21 CHECKING RING LAND 2 i Power r 9 9 Redistribution or publication of this document Generation by any means is strictly prohibited om WG PISTON CYLINDER WALL IMPROPER Y RING CONTACT T ts CT 1062 FIGURE 9 22 NEW RING IN WORN RING GROOVE improper width rings or excessive ring side clearance can result in ring breakage New rings in worn ring grooves don t have good cylinder wall contact Fig ure 9 22 Replace pistons showing signs of scuffing scoring worn ring lands fractures or damage from pre gnition Connecting Rod Inspection Replace connecting rod bolts and nuts with damaged threads Replace con necting rods with deep nicks signs of fractures scored bores or bores out of round more than 0 002 inch 08 05 mm Use a new piston pin to check connecting rod for wear A push fit clearance is required and varies from engine to engine If a new piston pin falis t
135. primary systems include the following e Cooling System e Exhaust System e Ignition System e Starter Motor e Crankcase Ventilation System e Governor e Fuel System Gasoline e Fuel System LP Gas Liquid Withdrawal The engine primary systems can often be serviced without removing the generator set from the recrea tional vehicle and without major disassembly of the set Use the following troubleshooting guide to help locate problems related to the engine primary sys tems Refer to Troubleshooting Generator Set Con trol for problems related to starting the generator set TROUBLESHOOTING ENGINE PRIMARY SYSTEMS Trouble Possible Cause Faulty ignition due to a worn or fouled spark plugs b worn ignition points c incorrect ignition timing d faulty ignition coil or e faulty plug wires Engine Misfires Lean fuel mixture due to a incorrectly adjusted fuel mixture screws b incorrect float level c dirt in carburetor d vacuum leak Contaminated fuel Carburetor icing Gasoline sets only Faulty ignition due to a incorrect ignition timing b incorrect spark plug gap Lean fue mixture due to a incorrectly adjusted fuel mixture screws b incorrect float level c dirt in carburetor Engine Backfires 3 Mechanical damage to engine Gasoline sets only Power Generation 6 1 Corrective Action Clean or replace spark plugs Replace breaker points Set breaker point g
136. pump outlet pressure Use the following procedure 1 Remove the fuel line from the pump outlet and install a pressure gauge 2 Press the START switch and hold it for several seconds until pressure reading is constant 3 The pressure reading for a good pump should fall within 3 1 2 to 5 psi 17 2 to 34 4 kPa The pressure should stay constant or drop off very slowly lf pressure reading is below 3 1 2 psi 17 2 kPa replace fuel pump if pressure reading is at zero stop engine crank ing and check elecirical connections Press the START switch and recheck pressure reading There are no serviceable components in the fuel pump Replace if defective FUEL SYSTEM LP GAS The fuel system must be in good condition and prop erly maintained for efficient generator set operation The main components of the fuel system are the air cleaner assembly carburetor intake manifold fuel filter solenoid valve vaporizer and two stage regula tor All LP gas generator sets utilize a liquid withdraw al system and are intended to share the vehicle LP gas fuel supply tanks The LP gas fuel supply tank must be designed with a dip tube to permit liquid fuel withdrawal The following sections provide basic information about LP gas fuel systems and specific service procedures for each fuel system component 6 19 Power Generation Redistribution or publication of this document by any means is strictly prohibited om L
137. quency and voltage first with a load applied and then with no load applied The fre quency and voltage should stay within the limits shown in Table 6 1 TABLE 6 1 VOLTAGE AND SPEED CHARTS VOLTAGE CHART FOR CHECKING 1 PHASE GOVERNOR REGULATION 2 WIRE Maximum 132 No Load Voltage Minimum 108 Full Load Voltage SPEED CHART FOR CHECKING GOVERNOR REGULATION Maximum No Load Speed Rpm 1890 Hertz Frequency 63 Minimum Full Load Speed 1770 Apm Hertz 57 5 Adjust the governor sensitivity to give the closest regulation least speed and voltage difference between no load and full load without causing a hunting condition To increase sensitivity closer regulation turn the sensitivity adjustment screw counterclockwise To decrease sensitivity turn the sensitivity adjustment screw clockwise SPEED ADJUSTMENT NUT SENSITIVITY ADJUSTMENT SCREW FS 1613 FIGURE 6 11 GOVERNOR ADJUSTMENTS 6 Recheck the speed setting made in step 3 and readjust if necessary 7 Setthe carburetor throttle stop screw as specified in the Fuel System section FUEL SYSTEM GASOLINE The fuel system must be in good condition and prop erly adjusted for efficient generator set operation The main components of the fuel system are the air cleaner assembly carburetor choke intake mani fold fuel filter fuel pump and air preheater When servicing disassemble assemble and adjust as spec ified in the foliowing sections Air Filter Assembly
138. r between the positive terminal on battery charge meter and ground Use the following to determine fault a lf reading equals battery voltage minus 10 volts battery meter is defective b lf reading does not equa battery voltage minus 10 volts zener diode is defective 7 14 Corrective Action Check for continuity and correct If circuit is open Check for continuity and correct If circuit is open Replace time meter Replace battery condition meter Replace zener diode Redistribution or publication of this document by any means is strictly prohibited Section 8 Generator INTRODUCTION The NHE and NHEL generator sets have a 4 pole revolving field generator with transformer voltage regulation All AC load connections are made through long generator lead wires that connect directly to a customer supplied junction box A circuit breaker provides overcurrent protection for the generator and also functions as an on off switch in the load circuit GENERATOR DESCRIPTION The generator see Figure 8 1 consists of the follow ing major components e Stator and Housing e Rotor e Voltage Regulating Transformer Field Current Rectifier Brushes e Wiring Harness Stator and Housing During generator set operation AC current is pro duced in the windings of the stator All stators have two AC output windings T1 T2 and T3 T4 for powering the load and a separate winding B1 B2 for battery charging Al
139. r the cooling fins on the engine and absorbs the heat The heated air is then discharged through the opening in the bottom of the Vacu Flo scroll Discharged cooling air can contain AWARNING poisonous exhaust gases which present the hazard of severe personal injury or death Never use discharged cooling air for heating the coach interior The generator compartment air inlet is sized see Section 2 SPECIFICATIONS to allow the required flow rate of air The air inlet opening and the air discharge opening must be kept free of any obstruc tions to avoid restricting airflow Dirt dust or other debris that may clog the air duct openings should be removed during periodic maintenance Dirt might also become lodged between the cooling fins onthe engine block and cylinder heads If this happens Power Generation 6 7 i iz i yt 2 Ri a oe i E we anf rg av ti yf SOON fr ge f By ANN Atty 44 AIR OUT CS 1266 FIGURE 6 3 COOLING AiR FLOW _ heat transfer is greatly reduced and overheating can occur if the fins are not cleaned The cooling system consists of the noise shield cylinder air housings scroll flywheel and scroll backplate When service is necessary disassemble and assemble the cooling system as specified in the following sections Disassembly Remove the muffler and tailpipe assembly see Exhaust System in this section to provide acc
140. resistor H1 Ghoke heater element K1 Start solenoid K2 Generator relay AC K3 Run relay K4 Start relay FIGURE 7 2 TYPICAL CONTROL SCHEMATIC GASOLINE in the lead wires from the board or remote start con trol The relays are sealed and filled with dry nitrogen for maximum contact life Start Run Stop Switch The Start Run Stop switch S1 is a single pole dou ble throw SPDT rocker type switch that is used for starting or stopping the generator set Placing the switch in either the Start or Stop position will initiate the appropriate control function The switch will automatically return to the center Run position when released The switch is mounted on the contro panel and is removable for service department Start Solenoid The K1 start solenoid is used for opening or closing the circuit between the starter motor and the battery Because of the high current loads imposed during starting the start solenoid is designed with heavy duty contacts rated to withstand 300 amperes A sin gle small terminal provides a connection point for the 12 volt DC solenoid coil Two large studs provide connection points for the battery cables The sole noid is mounted inside the control Battery Charge Resistor The battery charge resistor is a fixed value 2 5 ohm 50 watts resisior that limits the battery charge rate to no more than 1 ampere The charge rate may not be altered The resistor mounts between the left cylinder as viewed f
141. rews and then care fully disengage the starter from the stator housing 4 Remove starter through bolts and carefully separ ate the brush end cap housing and armature assembly 5 Use a 1 8 to 5 32 inch nail set to remove roll pin Remove return spring gear and clutch assembly as required When reassembling always use a new roll pin See Figure 2 UT SUPPORT FIGURE 2 DRIVING ROLL PIN OUT sm Power ta Generation Redistribution or publication of this document by any means is strictly prohibited Testing Armature for Grounds Touch one chmmeter lead to a commutator bar and then touch the other lead to armature shaft and core laminations Alow resistance reading indicates a grounded armature Replace grounded armaiure with a new part See Figure 3 FIGURE 3 TESTING ARMATURE FOR GROUNDS Testing for Shorts Use a growler Figure 4 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 the armature while slowly rotat ing armature in growler A shorted armature will cause the blade to vibrate and be attracted to the core Replace a shorted armature with a new part ES 1675 FIGURE 4 TESTING ARMATURE FOR SHORTS Testing for Opens Touch one ohmmeter lead to a commutator bar and then systematically touch the other iead to each of the remaining commutator bars A high resistance reading indicates an open circ
142. ring plate until it bottoms against the shoulder of the plate see Figure 9 34 Press or drive the front oil seal into the gear cover until it is 0 97 0 02 inch 24 6 0 5 mm from the mounting face of the cover USE GREASE IN SPACE BETWEEN SEALS TO IMPROVE SEAL GEAR COVER OF GEAR COVER OIL SEAL 0 97 0 02 INCH 24 6 0 5 mm GEAR COVER OIL SEAL MOUNTING FACE THIS SURFACE SHOULD BE CLEANED OF ALL OLD SEALING COMPOUND BE FORE INSTALLING SEAL Lubricate the lips of the replacement seal with a light coating of grease before installing the rear bearing plate or gear cover This provides initial lubrication until engine oil reaches the seal Refer to Crankshaft in this section for the rear bearing plate installation procedures Refer to Gear Cover in this section for the gear cover installation procedures ES THIS SURFACE SHOULD BE SL CLEANED OF ALL OLD SEALING COMPOUND BE FORE INSTALLING SEAL DRIVE OR PRESS OIL SEAL TO SHOULDER OF THE PLATE BORE REAR BEARING PLATE FIGURE 9 34 OIL SEALS Power Generation 9 16 Redistribution or publication of this document by any means is strictly prohibited Section 10 Service Checklist After servicing inspect and test the complete installa tion to confirm that the generator set will operate properly and will pull full rated load Check each of the following areas before putting the set into service MOUNTING Examine all mounting b
143. rn ends distortion and tension lf spring ends are worn check valve spring retainer for wear Check for spring distor tion by placing spring on a flat surface next to a square Measure height of spring and rotate it against square edge to measure distortion 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 or distorted Reconditioning Valves and Valve Seats The interference angle method of valve seating is used on all generator set engines With this method differ ent seat and face angles are used and line contact between the valve face and seat occurs The valve face angle is 44 degrees The valve seat angle is 45 degrees This 1 degree interference angle results VT t021 FIGURE 9 7 VALVE INTERFERENCE ANGLE in a sharp seating surface between the valve and the top of the valve seat see Figure 9 7 The valves should not be hand lapped because the sharp contact will be destroyed This is especially important where chrome cobalt faced valves and seats are used Valve faces must be finished in a machine to 44 degrees Every valve must have a minimum of 1 16 inch 1 6 mm margin Figure 9 8 If the valve has less margin than this it will heat up excessively It will retain that heat during the compression stroke and preignite the mixture causing loss of power and economy This vaive is also sus
144. rom flywheel end and the engine to generator adapter Optional Remote Start Control The remote start control is an optional accessory that allows the generator setto be started monitored and stopped from a remote location The deluxe control includes a running time meter and battery condition meter Remote control panels are usually mounted on the vehicle dashboard NHE CONTROL OPERATION This operation description applies to NHE series generator sets The schematic diagram shown in Fig ure 7 2 is intended as an example to help follow the circuit description Always refer to the specific wiring diagram that corresponds to the model and spec number of the generator set when troubleshooting problems Power Generation Redistribution or publication of this document by any means is strictly prohibited om PC BOARD ASSEMBLY CONTROL PANEL REAR VIEW START RUN STOP SWITCH REMOTE CONNECTOR SOCKET NOTE TAB IS AT BOTTOM OF SOCKET LO 0 Df ie HERRN Sy Mapa amp Ww STOP GND STAT GOMPONENT SIDE SC 1521 FIGURE 7 3 NHE CONTROL PANEL ASSEMBLY Starting Placing the Start Run Stop switch in the Start posi tion connects battery ground B to the K4 start relay This energizes the K4 relay which closes two sets of contacts K4 2 8 and K4 9 15 that connects battery positive B to the generator field windings CR4 Ti ignition coil E3 fue pump and K1 start solenoid Connecting B as descri
145. s clean and secure Also check for loose seams dents punctures and other mechanical damage If poor ignition performance is evident and other ignition components are not at fault the coil can be tested with the specified procedures When replacing the coil observe proper polarity The negative termi nal connects to the breaker points and the negative terminai connects to a battery B source within the control ignition Coil Testing A quick test of coil output can be made by checking the ignition spark Remove one of the spark piugs Reconnect the spark plug wire to the spark plug Ground the spark plug to bare engine metal and crank the engine A good spark should be observed beiween the plug center electrode and side elec trode If the spark is weak the coil points and con denser or wiring is probably defective Direct Testing With Ohmmeter To test a coil directly remove all the wires connected to it For easier access to the terminals the coil may be removed from the engine Use the following procedure to test 1 Inspect terminals for corrosion looseness cracks dents or other damage Look for evidence of electrical leakage around high tension termi nals indicated by carbon runners Damaged or leaking coils should be replaced 2 Clean the outside of the coil with a cloth dam pened in parts cleaning solvent Redistribution or publication of this document by any means is strictly prohibited 3 To
146. s a cee 4a Gow yaar en bk ce ee eee ewe wees oo cee acaweeee se wanen 10 1 GU DUT GGG icc sere ween wh eae ot ewes 6 anes oe see oe es ova eee tee eee esos neem wan 10 1 ERAS OVSICW acted paw trates one anew baad eka y na daebeed ease Gt sue eas EE AA hess 10 1 PS SYStO Nl cewsun ee E E E E EE E E tans dues 10 2 CONO 4 ogc cas acon aes ceeens coe eoeceeeee coe E AN E ee yaeesec tees sueewteane 10 2 etare L a i oseutesedseweceaeewaeceeenu isk eens E E EE 10 2 Power i Redistribution or publication of this document Generation by any means is strictly prohibited Section 1 Introduction The model number consists of code segments which designate various features or options The following typical model number is broken down to illustrate ABOUT THIS MANUAL This manual provides complete service information for Onan NHE NHEL series recreational vehicle generator sets for the experienced serviceperson Subjects covered include troubleshooting dis assembly repair reassembly and adjustments for engine generator and control The serviceperson must possess thorough knowledge of internal com bustion engine principles and basic knowledge of electrical fundamentals Refer to other Onan pubiica tions such as Electrical Mechanical Fundamentals 932 0408 Onan Generator Training Manual 932 0404 Operators Manual NHE GenSet 940 0122 and Installation Manual NHE GenSet 940 0622 for additional information Read all service and proce
147. s in acceleration and a greater tendency to burn valves and spark plugs Mixture screw adjustment should be checked with every engine tune up and whenever a carburetion probiem is suspected Before adjusting be sure the ignition system is working properly and the governor is correctly set If the carburetor is totally out of adjustment use the mixture settings given in Table 6 2 as preliminary adjusiments Turn the mixture screws in until lightly seated then turn out the speci fied number of turns Power Generation oe Redistribution or publication of this document by any means is strictly prohibited am CHOKE PULL OFF AIR PREHEATER l li o CARBURETOR INTAKE MANIFOLD i FUEL LINE GOVERNOR CONTROL LINKAGE FS 1607 FIGURE 6 13 CARBURETOR AND INTAKE MANIFOLD ASSEMBLY ACAUTION Forcing the mixture adjustment 1 Stop the set and connect a voltmeter frequency screws tight will damage the needle meter and load bank to the generator output and seat Turn in only until light tension can be felt leads 2 Start the generator setand apply a full load Verify that the frequency is within 59 2 hertz and adjust the governor speed adjustment nut if necessary to obtain required frequency 3 Turnthe main adjustment screw inward until volt aie age or frequency drop again Locate the point ADJUSTMENT where the voltage and frequency are highest SCREW From this setting turn the main adjustment
148. s strictly prohibited om om 5 Remove the breaker poinis mounting screws screw GC and lift out the point assembly POINT GAP ES 1529 FIGURE 6 6 BREAKER POINTS 6 Replace the condenser and point assembly and install in reverse order of removal 7 Useanallen head wrench to adjust set screw D to obtain the gap setting specified in section 2 Specifications Measure the point gap with a flat thickness gauge see Figure 6 6 Clean points after adjusting Make sure feeler gauge is clean and free of any grease oil or dirt The timing is adjusted during initial engine assembly and is fixed by the point gap adjust ment No other adjustment or alignment is necessary 8 Replace the point box cover spark plugs and spark plug leads 9 Connect negative battery cable to negative battery terminal Igntion Coil The ignition coil is a transformer that steps up the battery voltage to about 20 000 volts for spark plug firing The coil is composed of a primary winding secondary winding sealing compound bakelight cap and the outside case and necessary terminals Figure 6 7 Power Generation SECONDARY WINDING 6 9 HIGH TENSION TERMINALS ASA rf LOW TENSION Sits MTs LOW TENSION TERMINAL 5 TERMINAL Gin PRIMARY WINDING IRON CORE ES 1329 FIGURE 6 7 IGNITION COIL Ignition coils do not normally require any service other than to keep all terminais and connection
149. set the voltage drop that would normally occur when a load is applied In the same manner decreasing the load reduces the DC field current to offset the voltage rise that would normally occur when a load is removed Continuously adjusting the field current as the load changes is how voltage regulaton is achieved GENERATOR TROUBLESHOOTING Use the following troubleshooting guide to help locate problems related to the generator Figures 8 1 and 8 2 show the location of most of the generator components Refer to the wiring diagram in Figure 8 4 for the location of allterminal connections The troubleshooting guide is divided into four sections After identifying the problem refer to the guide for the possible cause and the recom mended corrective action Ro GNOCGAEEN TO TAANSFORMER GND ES 1557 FIGURE 8 2 VOLTAGE REGULATING TRANSFORMER Power 8 3 Generation Redistribution or publication of this document by any means is strictly prohibited om hi RG Al Pi Al CRI AI FI KI AI K4 W2 AfPi2 os oe Al K4 yes i mm C Al ay py ro a Tl El life f Has t a Al PI S AK3 p AK3 J REMOTE i yz P AL CR2 Al P3 6 pal Tar l RI Al K2 Al K3 SZ kA SRA e30 AO AK3 OWO AP33 Id or START STOP AI P3 NOMINALNOLOADVAC HI T2 Xx 127544 5 VAC LEADS f e SHINS CRA AC SI ab y TODECREASE X2 X6 B Se Ma x5 NOMINALNO xalx6 B2 LOAD VAC 40 i BUS BAR NORMAL iX2 X5 T O
150. t ing battery positive B to the top terminal and bat tery negative B to the grounded terminal The plunger assembly should withdraw and open the valve when the solenoid is energized Replace the solenoid valve if it does not operate properly 3 a Power r 6 25 Redistribution or publication of this document aa Generation by any means is strictly prohibited 6 26 Redistribution or publication of this document by any means is strictly prohibited Section 7 Control INTRODUCTION The control system includes all functions that relate to starting monitoring for fault conditions instru mentation battery charging and stopping This sec tion covers how the control operates where the com ponents are located and basic troubleshooting pro cedures Separate control systems are used for the NHE and NHEL series generator sets Each system is covered separately in this section NHE CONTROL DESCRIPTION The generator set contro see Figures 7 1 and 7 2 consists of the following components e Printed Circuit Board Assembly e Panel Mounted Start Run Stop Switch S1 e Start Solenoid K1 e Battery Charge Resistor R6 Optional Remote Start Control A general description of each component and how it functions follows Printed Circuit Board Assembly The printed circuit board assembly see Figure 7 3 is the center of the generator set control system The PC board circuitry controls the start starter discon
151. t switch 3 Breaker points CR1 Power rectifier CR4 Fieid rectifier Fi Fuse 61 Starter motor G1 Generator START SOLENOID STARTER MOTOR ETEA SWITCH RUN LIGHT REMOTE BATTERY CONDITION METER TOTALIZI TIME Me nS ES 1547 1 1 Spark plug E2 Spark plug E3 Fuel solenoid R6 Battery charge resistor K1 Start solenoid K2 Generator relay AC K3 Run relay K4 Siart relay K5 Stop relay FIGURE 7 5 TYPICAL CONTROL SCHEMATIC LP GAS NHEL CONTROL OPERATION This operation description applies to NHEL series generator sets The schematic diagram shown in Fig ure 7 5 is intended as an exampie to help follow the circuit description Always refer to the specific wiring diagram that corresponds to the model and spec number of the generator set when troubleshooting problems Starting Placing the Start Run Stop switch in the Start posi tion connects battery ground B to the K4 start relay This energizes the K4 relay which closes two sets of contacts K4 2 8 and K4 9 15 that connect battery positive B to the generator field windings CR4 T1 Ignition coil 3 fuel solenoid valve K5 stop relay and K1 start solencid Connecting B as described produces the following control responses e Flashes the field to ensure that there is adequate residual magnetism to induce voltage build up s Energizes the ignition coil 11 so it can begin producing an ignition spark when the breaker points open
152. tch start solenoid battery charge resistor and remote start control The following sections pro vide a description of the stop relay and blocking diode Stop Relay K5 The K5 stop relay is used to latch off the generator set when the Start Run Stop switch S1 is placed in the Stop position This prevents the set from restarting when the switch is momentarily placed in the Stop position and then released The K5 relay mounts on the air cleaner adapter Blocking Diode CR5 The CR5 blocking diode is used to protect the control circuitry from reverse flow transient currents When the set is shut down various magnetic fields within the generator collapse This causes transient cur rents that can damage the control if not blocked The CRS diode is spliced into the contro wiring harness between the circuit board assembly and Start Run Stop switch MOUNTS BEHIND K5 RELAY MOUNTS ON AIR CLEANER ADAPTER ai 2 Pi f 10 RG 2 Pi 2 TG KI S Pi 3 TO IGN COlt 6 Pi 4 TO LOPKO PI amp 70 CH4 PI 6 TO Kt 8 PI 7 TO TERMINAL TAB P1 8 TO TERMINAL TAB C 1520 FIGURE 7 4 NHEL CONTROL Power 7 8 Generation Redistribution or publication of this document by any means is strictly prohibited B2 P2 2 g1 amp STOP l SZ Ad RUN ksl LOP a START 87A p3 TO REMOTE SWITCH P2 3 P2 4 1 Start Run Stop switch 2 Low ail pressure cut ou
153. tem due to its exposure to intense heat Out of round wear follows when the seat is pounded by a valve whose head is not in line with the stem and guide if a valve face is burned or warped or the stem worn install a new one Too much clearance in the intake guide admits air and oil into the combustion chamber upsetting carbure tion increasing oi consumption and making heavy 9 2 Redistribution or publication of this document by any means is strictly prohibited carbon deposits Carbon prevents heat dissipation Clean metal is a good heat conductor but carbon insu lates 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 cause pre ignition and pinging Vaive Stem Seal A valve stem seal is used on the intake valve guides This seal must be replaced each time the valve is removed Stems and Guides Always check valve stems and guides for wear as shown in Figure 9 6 Use a hole gauge to measure the valve guide When clearance with stem exceeds original clearance by 0 002 inch 0 05 mm replace either valve or guide or both as may be necessary Always regrind seat to make concentric with the newly installed guide VT 1020 FIGURE 9 6 VALVE STEM AND VALVE GUIDE INSPECTION Spring Check valve springs for cracks wo
154. ting element cover Inspect the heating element and replace if burned out or broken Also inspect the bi metal spiral strip and replace if damaged deteriorated or dragging in the housing When installing a new bi metal sirip maintain the orig inal direction of spiral see Figure 6 20 The outer tab must point in a clockwise direction Make sure the coil sets squarely in the housing and the inner end of the coil engages the slot in the choke shaft When instal ling the element cover make sure the slotted tang on the cover engages the bi metal strip CHOKE LEVER CHOKE PLATE CLOSED PULL OFF LINKAGE PULL OFF DIAPHRAGM ENG MEASURE E ce DIAPHRAGM MTG BRKT BEND HERE FS 1603 FIGURE 6 21 CHOKE PULL OFF DIAPHRAGM Choke Pulloff Diaphragm Adjustments The choke pull off diaphragm partially opens the choke plate following engine startup This helps prevent flooding and provides for smoother engine operation as the sei is warming up Use the following procedure to adjust 1 Remove the complete air filter assembly as speci fied in the air Filter Assembly in this section to provide access to the choke plate 2 Disconnect diaphragm hose from intake manifold and apply 4 to 18 inches 102 to 457 mm Hg vacuum to the diaphragm 3 Apply light finger pressure against the choke lever to take up all freeplay in the pulloff linkage see Figure 6 21 4 Check alignment as viewed from the top of diaphragm stem pullof
155. tion or publication of this document by any means is strictly prohibited Power _ Generation om Disconnect the lead wires from the K5 relay terminals Remove the three capscrews that secure the air cleaner adapter to the carburetor and lift off the adapter Remove the two capscrews that secure the K5 relay bracket to the adapter and lift off the relay assembly Disconnect the fuel hose and governor control linkage from the carburetor Remove the two capscrews that secure the car buretor to the intake manifold and lift off the carburetor Use the following procedures if it is necessary to remove the intake manifold A Disconnect the flexible fuel supply line from the fuel vaporizer Remove the exhaust manifold as described in EXHAUST SYSTEM in this section to provide clearance for lifting off the intake manifold Bending the fuel vaporizer ACAUTION tubing will weaken the metal which might cause cracks to form Do not bend the vaporizer tubing to remove the intake manifold B Remove the intake manifold capscrews and lift off the intake manifold Remove the two intake manifold gaskets from the block and plug the intake ports with rags to prevent loose parts from accidentally entering the ports Assembly Reverse order of disassembly Use new gaskets between the exhaust manifold and engine the intake manifold and engine and carburetor and intake manifold Tighten exhaust and intake manifol
156. toward the valve head Tappets are also replaceable from the valve chamber after first removing the valve assemblies Removal Before removing valve guides use an elect ric drill with a wire brush to remove carbon and other foreign material from top surface of guides Failure to perform this operation may result in damage to the guide bores Drive the guides out with a hammer and valve guide driver Driving out old guides can damage 4 CAUTION fhe tapped bores Be caretul not to strike bores with driver installation Run a small polishing rod with crocus cloth through valve guide holes to clean out carbon a IA 9 P 5 16 18 HEX NUF 2 REQUIRED 7 IN ZA 1 1 4 IN 178 mm AY NC 32 mm 5 16 FLAT WASHER 2 REQUIRED 4 3 4 N 121 mm 5 16 18 THREADED ROD 2 3 8 IN 60 mm 5 8 IN VT 1023 16 mm FIGURE 9 9 VALVE GUIDE INSTALLATION Power 9 4 Generation and other foreign materials Place a new gasket on the intake valve guide and coat the outer edge of each new guide with oi Place guide notch up in cylinder block and press in until shoulder of guide rests against the cylinder block A suggested method of installation is shown In Figure 9 9 Valve Seats Inspect valve seat inserts tf seats are loose cracked or severely pitted new inserts must be installed Remove valve seat inserts using a valve seat removal tool Removal Remove carbon and combustion depos
157. tween terminals 5 and 6 on remote start stop switch If jumper is in place connect a voltmeter between the positive terminal on battery charge meter and ground Use the following to determine fault a if reading equals battery voltage minus 10 volts battery meter is defective b If reading does not equal battery voltage minus 10 volts zener diode is defective 7 7 Corrective Action Check for continuity and correct If circuit is open Check for continuity and correct if circuit is open Replace time meter Replace battery condition meter Replace zener diode Redistribution or publication of this document by any means is strictly prohibited NHEL CONTROL DESCRIPTION The NHEL generator set control see Figures 7 4 and 7 5 consists of the following components o Printed Circuit Board Assembly e Panel Mounted Start Run Stop Switch 1 Start Solenoid K1 Battery Charger Resistor R6 Optional Remote Start Conirol Stop Relay K5 Blocking Diode CRS The first five components listed for the NHEL control are either the same or similar to the components in the NHE control Refer to NHE Control in this section and Figure 7 6 for a genera description of the printed circuit board assembly panel mounted Start Run TO IGNITION COIL B From K5 85 fo pD LEFT CYLINDER R6 CHARGE Bi RESISTOR 82 TO TERMINAL TAB R6 1 _ aor TD A6 1 TO K5 85 es 6 2 TO K5 87A Stop swi
158. uit between the commutator bars and armature windings Replace an open armature with a new part Brush Inspection Measure brushes Figure 5 and replace if worn less than 425 inch 14 mm 0 425 INCH 17 mm WEAR LIMIT NEW 0 570 INCH 14 5 mm L ES 1610 FIGURE 5 BRUSH INSPECTION Power _ 2 Generation Redistribution or publication of this document by any means is strictly prohibited om TORQUE TO 5 10 IN LBS 57 1 13 Nem POSITIVE BRUSH STUD TORQUE TO 25 30 IN LBS 2 83 3 39 Nem IMPORTANT THIS INSULATED SHUNT MUST BE ROUTED THRU UNINSULATED SHUNT AS SHOWN TO PREVENT CONTACT WITH COMMUTATOR IN FINAL ASSEMBLY NEGATIVE BRUSH TERMINAL BRUSH SPRING CONTACT LOOP om NEGATIVE BRUSH TERMINAL IMPORTANT SPRING MUST BE ASSEMBLED ON MOUNTING TAB AS SHOWN ES 1612 FIGURE 6 BRUSH ENDCAP Assembly 1 Wipe off all dirt and oil from starter components using a clean cloth or blow off dirt with filtered low pressure compressed air Oil on armature will damage ACAUTION Siarter Do not immerse bear ings in cleaning fluid Use a brush dipped in clean engine oif for removing dirt from bearings Avoid getting oif on brushes or commutator Power Generation Mount brush springs on tabs as shown in Figure 6 Using a small screwdriver turn spring counter clockwise to torque so contact loop is inside of brush holder Spring should be pushed down to mounting ta
159. uit in wiring between 1 switch and PC board b faulty 1 switch Insufficient voltage for 3a cranking due to a battery not charged b terminal connections loose or dirty Sb Control fuse F1 is open Connect a voltmeter between 5a terminal S on the start Sole noid and ground Check for battery voltage when 1 is placed in Start position If voltage is present fault is due to a Ki relay not grounded b defective K1 relay c defective starter 5b 5c lf voltage is not present as 6a described in step 5 test fauit is due to a open circuit between K1 relay and control PC board b defective control PC board 6b 7 11 1b Corrective Action Check for continuity and and correct if circuit is open Replace remote start contro switch Check for continuity and correct if circuit is open Replace S1 switch Check condition of battery and recharge or replace Clean and tighten all connections at battery K1 start solenoid and Starter motor AWARNING Short circuiting the battery cables can cause severe personal injury or death Disconnect the negative battery cable at the battery terminal before servicing Replace fuse 5 ampere Tighten solenoid bracket mounting screws Replace Kt start solenoid Refer to Electric Starter section for test and service procedures Check for continuity and correct if circuit is open Replace contr
160. ure should stay constant or drop off very slowly A low pressure reading with little or no pressure drop indicates a weak or broken diaphragm or diaphragm spring worn linkage or leaky check valves If pressure is above maximum the pump diaphragm is too tight or the diaphragm or plunger return spring is too strong Any of the above conditions are cause for repair or replace ment of the pump Power Generation 6 18 Redistribution or publication of this document by any means is strictly prohibited om Fuel Pump Repair for units built June 1986 and before Service of the fuel pump is limited to the bottom cover plunger tube and plunger assembly All parts of the electric system are hermetically sealed in a gas atmosphere and are not serviceable If electrical failure occurs replace the pump Do not tamper with the seal at the center of the mounting bracket on the side of the pump as it retains the dry gas which surrounds the electrical system Electrical system components are not serviceable Use the following procedure for servicing the pump 1 Using a gas pliers loosen the pump cover then remove by hand 2 Remove the magnet and cover gasket Figure 6 22 PUMP ASSEMBLY FS 1487 FIGURE 6 22 FUEL PUMP ASSEMBLY June 1986 and before 3 Using a thin nose pliers remove the retainer spring from the plunger tube Remove the washer O ring seal Cup vative plunger spring and plunger from tube
161. ure to adjust 1 Stop the set and connect a volimeter frequency meter and load bank to the generator output leads Start the generator set and apply a full load Verify that the frequency is within 59 2 hertz and adjust the governor speed adjustment nut tf necessary to obtain required frequency Turn the main adjustment screw inward until volt age or frequency drop and then outward until volt age or frequency drop again Set the main adjust ment screw at the point where the voltage and frequency are highest Remove the load and verify that frequency is within 62 1 hertz Adjust governor speed adjustment nut if necessary to obtain required frequency Turn the idle adjustment screw inward until volt age and frequency drop and engine begins to run rough or starts hunting Back out idle adjustment screw until engine runs smoothly without hunting Pull the governor linkage toward the front of the set so that the throttle lever on the carburetor is resting against the throttle stop screw Adjust the stop screw to obtain a setting of 55 hertz and 100 4 5 volts Release the governor linkage and observe the sta bility of the set Set the voltage and frequency and adjust the sensitivity of the governor as specified under Governor in this section Add and remove a half load several times to make certain the set does not bog down or hunt Power Generation 6 21 Redistribution or publication of this document by
162. vaporized Remove regulator front cover and diaphragm assembly see Figure 6 29 to check for dirt or oil deposits If granules are embedded in the Vitton rubber of the secondary valve wash the valve and seat clean Regulator Test The regulator may be bend tested using compressed air and a simpte automobile fuel pressure gauge Use the following procedure to tesi FIGURE 6 30 REGULATOR TEST 1 Attach the pressure gauge to the test port on the back of the regulator as shown in Figure 6 30 2 Attach a pressure hose to the inlet opening and open the air pressure valve 3 If the primary seal is sound the gauge should read approximately 1 1 2 psi 10 3 kPa and the pressure should remain constant A fluctuating pressure reading indicates a bad primary seat 4 Close the air pressure valve and observe the pres sure gauge The pressure should remain con stant If the pressure reading drops the secon dary seat is leaking lf the regulator does not pass either test it must be rebuilt or replaced Fuel Filter The fuel filter see Figure 6 31 removes solid impuri ties such as rust or scale from the LP gas before they can clog the regulator or carburetor A magnet within the filter housing traps iron or rust particles while a filter element traps non magnetic particles The fuel filter operates at container pressure and must be carefully assembled to prevent leakage Use the fol lowing procedures to disassemble and c
163. ve the throttle lever to the completely closed position Seat the plate by gently tapping on it with a small screwdriver and then tighten the screws Install seal throttle stop tever and collar on the throttle shaft end DAMAGE AND WEAR OCCUR HERE F3 1483 FS 1602 FIGURE 6 27 MIXTURE NEEDLE INSPECTION LP GAS FIGURE 6 26 CARBURETOR OVERHAUL s t Power 6 22 Generation Redistribution or publication of this document by any means is strictly prohibited om om 2 Install the idle and main adjustment screws and turn in until lightly seated For preliminary set tings turn the idle screw out 1 1 4 turn and the main screw out 2 1 2 1 4 turns Forcing the mixture adjusiment ACAUTION screws tight will damage the needie and seat Turn in only until tension is felt 3 Join the upper and lower sections of the carbure tor and install bowi plug and washer 4 When the carburetor is installed on set make final adjustments to mixture screws as specified in Carburetor Mixture Screw Adjustments in this section Regulator A two stage regulator see Figure 6 28 is used to deliver vaporized LP gas fuel to the carburetor The primary stage of the regulator receives LP gas at container pressure and reduces it to the low pressure required for set operation The secondary stage of the regulator restricts fuel flow through the regulator until vacuum from the engine creates a demand for fue
164. ver from the end of the throttle shaft 2 Remove the throttle plate retaining screws and throttle plate Remove dust seais from throtile shaft and carefully pull out throttle shaft 3 Remove main and idle mixture screw assembly 4 Separate lower section bowl of carburetor from the upper section bowl cover Clean and Repair When the carburetor is completely disassembled clean and repair using the following procedures 1 Soak all metal components not replaced by repair kit in carburetor cleaner Do not soak any non metal parts or they may be damaged by the clean ing solution Follow the cleaner manufacturers recommendations 2 Clean all carbon from throttle bore especially where the throttle plate seats Be careful not to plug the idle or main fuel parts 3 Blow out all passages with low pressure 35 psi 241 kPa compressed air Do not use wire or other objects for cleaning that might increase the size of critical passages 4 Check the condition of the mixture screws see Figure 6 27 and replace if worn or damaged 5 Replace all old components seals and gaskets with new parts included in the kit Reassembly and Installation When the carburetor parts are clean and dry reassemble using the follow ing procedure 1 Slide in throttle shaft and install throttle plate using new screws if furnished in repair kit Before tightening the screws the plate must be centered in the throttle bore To do so mo
165. y transformer when troubleshooting instead i check each lead from point to point to confirm that unit is wired properly i 6l1 1174 NOTES 1 JUMPER IS NEEDED FOR BATTERY CONDITION METER TRANSFORMER IGN COIL E3 FUEL PUMP OR FUEL SOLENOID IGN POINTS E12 SPARK PLUG SWITCH LOW OIL PRESSURE CBi 2 CIRCUIT BREAKERS AC OUTPUT SWITCH START STOP CR4 BRIDGE RECTIFIER RESISTOR BATTERY CHARGE C1 CAPACITOR RELAY USED WITH LPG ONLY BTi BATTERY 12V START SOLENOID BT STARTER CHOKE USED WITH GASCLINE ONLY A3 STANDARD REMOTE CONTROL GENERATOR A2 DELUXE REMOTE CONTROL FUSE At CONTROL ASSY FIGURE 8 4 TYPICAL WIRING DIAGRAM i 8 5 Redistribution or publication of this document by any means is strictly prohibited Trouble No AC Output Voltage Note This condition may cause the generator set to stop when the Start switch is released AC Output Voltage Too Low Or Too High Noisy Generator TROUBLESHOOTING THE GENERATOR Possible Cause Open circuit breaker Open circuit between brush block and CR 4 rectifier Brushes stuck in holder or not making good contact with slip rings Defective CR4 bridge rectifier Open grounded or short circuit in rotor stator or transformer Engine governor incorrectly adjusted Open diode in CR4 bridge rectifier Brushes worn or not making good contact with stip rings If generator frequency is within specified limits but v

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