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927-0550 Onan MCCK Marine Genset Major Service manual (04

1. AUX RELAY BILGE BLOWER NEG GROUND POWER SOURC FIGURE 41 CONNECTING BILGE BLOWER TO CONTROL O MATIC The bilge blower operates on power from the electric plant cranking battery The optional switch will run the bilge blower as long as the switch is closed The bilge blower running current must not exceed 5 amperes 0 2 E ES NE 0 3 EC LAM 9 9 gt 8 OPTIONAL MANUAL SWITCH INE 24 TO RUN BILGE BLOWER NEG GROUND FIGURE 42 CUN TROUBLE SHOOTING PROCEDURE FOR SINGLE PHASE A 20 000 Ohm Volt VOM is needed for some of the following tests 120 VOLT 12VOLT DC CONTROL O MATIC The symptoms are listed by number and followed by test procedures 1 Control switch is RUN position but electric plant does not crank after the usual 5 minute delay period a b Check battery connections and battery voltage Disable the bilge blower control Relay by moving the lead wire from Terminal 1 to Terminal 3 Figure33 If plant cranks with the bilge blower control disabled the problem is in the bilge blower control circuit Refer to Paragraph 5 Check to see if the Start Solenoid Kg picks up it doesn t check for a faulty solenoid by connecting a jumper from the S terminal to ground This bypasses contact and start solenoid Should pick up If it picks up check for proper operation of relay
2. GIONS 105 329 SOEGN 72999 40 SM o2V 40 AVIae 553 02YI34AM ASSMNOSSIQ laws c A a E x UE A BOIINGAN Af 39V110A 4315 2 o 5 11 6 AIOE VNIH BAL gt Al Cz 19 IN 060 is 1 ee L 182 V VOREN L 0151834 Of WHO 1 EG2RLOTEN 016 vorguZzsan ANN valid SUR AN ANSP USA 2215 j 91214 907214 31835 46 46922 BRIM 2 110 0z1 1236 1 22 50925 OW 0332 DC ACO SLI nuin 4 02 S NOIL NOI alis T HOLMS EE DELIE PITT MALwAA HOM 1 SOR Td ev yas li 1 H Paes ES mel S1NIOd NOLLINS a c LSEGEEE NOIL vBLIShT 1 5638 405 L6S2810t 5 2520 SN UNIS AYIN N 3 10 XOB 1 N 4045163 H v21210 BN H3A0D A 7 5 52565 2891406 SN TORINO ZSEZIIOT SN ASS Y 2 X08 1081802 HILIMS 130 MON 202 242313 NYNO F Ta I 559 aN 30 91539 i sit Awa live mo
3. e aa i L nay TM s MAJOR SERVICE MANUAL SWONAN DIVISION OF STUDEBAKER CORPORATIO TABLE CONTENTS TITLE PAGE Introduction 3 Specifications 4 Table of Clearances and Torques 5 Trouble Shooting 6 Cooling System 9 Fuel System 12 Ignition System 18 Governor System 20 Valve Service 22 Engine Disassembly 24 Generator 29 Control System 33 Wiring Diagrams 45 ELECTRIC GENERATING PLANTS MCCK _ jut _ SERIES T This manual contains information for the proper servicing of MCCK electric generating plants For installation preparation and operating instructions refer to Operators Manual Instructions for 60 cycle 1 800 rpm plants also apply to 50 cycle 1 500 rpm plants except for current frequency and operating speed The engine end is designated as the front end of the plant side and right side of the plant are determined by viewing from the front end IMPORTANT RETURN WARRANTY CARD ATTACHED TO UNIT MEMORANDUM D INTRODUCTION Instructions in this manual may refer to a specific model of generating plant Identify the model by referring to the MODEL AND SPEC specification NO as shown on the plant nameplate Electrical characteristics are shown on the lower portion of the plant nameplate w How to read MODEL and SPEC NO 605MCCK 3R 1A 11 2 34 1 Factory code for general identification
4. and K2 2 Electric plant will not start on load demand a Move the toggle switch to RUN position Plant Should crank after approximately a five minute delay Apply some load at least 100 watts to load the circuit Move toggle switch to AUTO position Plant should continue running If plant stops with 100W load move toggle switch to OFF position Connect a jumper wire from terminal 8 of Relay K4 to the ground terminal in the Control O Matic Move toggle switch to AUTO Plant should start and run If it does not remove relay to check continuity of relay coil terminals 2 3 and 8 of 307462 Resistance 2 3 equals approximately 100ohms 2 8 equals approximately 1000 ohms Apply 6 to 12 volts to terminals 2 8 to see if relay operates and contacts 6 7 close If relay is good check voltages as follows The voltage from the chassis ground terminal to the terminal the Start Solenoid should equal battery voltage terminal 2 of relay socket should equal battery voltage terminal 3 of Start Run relay should be near zero if contact is closed properly and sufficient load is connected to the Load circuit Check voltages of load sensor amplifier with plant running under a minimum load of 100 watts Start electric plant in AUTO position for this test by jumpering the outside terminals of Switch 51 Measure AC output voltage of Transformer at terminals on
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6. 32 1 phase 5500 6500 3 5 Yes Yes Yes lt TABLE OF CLEAR TABLE OF Tappets at 70 F Valve Stem in Guide intake Valve stem in Guide exhaust Valve Seat Interference Width Valve Face Angle Valve Seat Angle Valve Interference Angle Crankshaft Main Bearings Steel Backed Aluminum Crankshaft End Play i Camshaft Bearings Camshaft End Play Connecting Rod Bearing Connecting Rod End Play Timing Gear Backlash Oil Pump Gear Backlash Piston to Cylinder Conformatic Type Measured below oil controlling ring 90 from pin Piston Pin in Piston at 709 Piston Pin in Rod at 70 F Piston Ring Gap in Cylinder Breaker Point Gap Full Separation Spark Plug Gap For Gaseous Fuel Spark Plug Gap For Gasoline Fuel Crankshaft Main Bearing Journal Standard Size Crankshaft Rod Bearing Journal Standard Size Cylinder Bore Standard Size Ignition Timing Advance Cooling System Capacity Including Heat Exchanger CLEARANCES ASSEMBLY TORQUES Assembly torques require the use of torque wrench These torques assure proper tightness without danger of stripping the threads TORQUE SPECIFICATIONS FT LBS Rear Bearing Plate Nuts 20 25 Connecting Rod Bolts 27 29 Oil Pump Mounting Screws 7 9 Oil Base Screws 43 48 Generator Adapter Screws 20 25 Timing Gear Cover Screws 15 20 Minimum 0 0117 0 001 0 0025 1 225 0 0025 0 0067 0 0015 0 0037 0 0005 0 0027 9 0027 0 00
7. If a major gen erator repair becomes necessary have the equipment checked by a competent electrician thoroughly familiar with its operation Continuity tests may be performed without disassembly of the generator DISASSEMBLY P 1 The first step is to remove generator band and end bell cover Remove all brush springs and lift the brushes from their holders 2 Remove generator through stud nuts Hold both the end bell and frame assembly since they are separate parts and remove them as one assembly from the adapter Screwdriver slots in the adapter provide for prying the frame loose careful not to let the frame assembly rest or drag on the armature 3 Remove baffle ring from adapter Turn armature through stud nut out to the end of the through stud While pulling the armature outward with one hand strike a sharp endwise blow on the nut with a heavy soft faced hammer to loosen the armature If the armature does not come loose strike the armature with a sharp downward blow in the center of the lamination stack with a lead or plastic hammer Rotate the armature and repeat Be careful not to hit the collector rings commutator bearing or windings 4 Upon disassembly all parts should be wiped clean and visually inspected BRUSHES AND SPRINGS Inspect brushes periodically Replace if worn to 5 87 Replace springs if damaged or if proper tension is ques tionable Rapid brush wear may be caused from high mica betw
8. check the ring gap by placing each ting squarely in its cylinder at a position correspond ing to the bottom travel The gap should be as given in the Table of Clearances Slightly oveisize rings may be filed as necessary to obtain the correct gap but do not use rings requiring too much filing Standard size rings may be used on a 005 oversize piston 010 020 030 and 040 oversize rings ate to be used on 010 020 030 and 040 oversize pistons respectively Tapered rings are usually marked on one side identified in some other manner Rings must be installed with this mark toward the closed end of the piston Space each ring gap 90 from the preceding one with no gap in line with the piston pin The bottom piston ring groove should be fitted with an oil control ring plus expander and the two upper grooves fitted with compression rings PISTON RING IN CYLINDER BORE FEELER 2 NO 10 32 SCREWS FIGURE 21 TIMING GEARS AND GEAR PULLER 25 If chrome faced ring is used it will be in the top groove The oil control ring is selected for best performance in regard to the correct unit pressure characteristics Pistons are fitted with full floating piston pins pin is retained by two circlips in each boss Be sure these lock rings are properly in place before installing the piston assembly Correct piston to cylinder clearance appears in the Table of C
9. replace as needed Testing Field Windings for Open Circuit To test a coil assembly for an open circuit disconnect its external leads and touch one test prod to the terminal of one coil winding lead and the other test prod to the other lead or leads of that coil winding If the lamp does not light the winding being tested is open If the fault lies in a connection between coils or in a coil lead the connection can be repaired If it is inside the coil replace thg entire coil assembly with a new one Ball Bearing If the armature ball bearing needs replace ment pull the bearing from the shaft with a suitable bearing puller Do not damage the armature shaft it must remain true to serve as a turning center when refinishing the commutator or collector rings Drive the bearing onto the shaft shoulder Use double sealed prelubricated ball bearing Shunt Field Rectifier Using a multimeter check the rectifier for an open circuit in one direction and a closed circuit in the other direction If the rectifier is defective in either direction replace it Assembly 1 Clean and inspect all mating surfaces should be free of nicks and dirt Surfaces 2 Coat mating area between the generator shaft and the engine crankshaft with a thin film of lubricating oil Molycoat or equal 3 Assemble the armature through stud to the engine crankshaft with required torque 4 Check to see that the key is in the crankshaft TEST
10. Clean or increase size AT LIGHT LOAD Clean Set gap Replace gaskets if necessary Clean adjust or replace breaker points spark plugs condenser etc or time ignition AT HEAVY LOAD Replace Clean adjust or replace breaker points spark plugs condenser etc ignition Clean carburetor or time Clean Replace AT ALL LOADS Clean and adjust Replace Grind valves Replace Adjust or replace breaker points POSSIBLE CAUSE REMEDY LOW OIL PRESSURE Oil too light or diluted from leaking fuel pump diaphragm Oil too low Oil relief valvenot seating Badly worn bearings Sludge on oil screen Badly worn oil pump Defective oil pressure gage Oil too heavy Clogged oil passage Oil relief valve stuck Defective oil pressure gage ENGINE BACKFIRES Clean carburetor Lean fuel mixture Clogged fuel filter Air leak at intake manifold or carburetor flange Poor fuel Spark advanced too far Intake valve leaking Drain fill with proper oil Repair or replace fuel pump Add oil Remove and clean or replace Replace Remove and clean Replace Replace HIGH OIL PRESSURE Drain fill with proper oil Clean all lines and pass ages Remove and clean Replace AT CARBURETOR Adjust jets Clean Tighten mounting screws Replace gaskets as neces sary Fill with ee fies fuel Re set breaker or t
11. Install the main nozzle Spec only making sure it seats in the body casting Install the fuel inlet valve seat and valve Install the float and float pin Center the pin so the float bowl doesn t ride against it Check the float level with the carburetor casting inverted See Figure 14 i Install the bowl ring gasket bowl and bowi nut and main jet begin Spec B Make sure that the bowl is centered in the gasket and tighten the nut securely Install the load adjusting needle with its spring Turn in until it seats and back out 1 to 1 1 2 turns Install the idle adjusting screw finger tight Then back out 1 to 1 1 2 turns Reinstall the choke and adjust Install the silencer assembly and gasket Install the carburetor on the engine and connect the gasoline inlet governor mechanism breather hose and choke Install the silencer THIS DIMENSION SHOULD BE 1 764 BEND TAB TO ADJUST THIS DIMENSION SHOULD BE TO FLOAT P C TAB CONTACTING BOWL FLANGE HEAD OF PIN WITH FULL WEIGHT OF FLOAT COMPRESSING INLET VALVE SPRING BEGIN GASKET SPEC B A913 Rey FIGURE 14 SETTING FLOAT LEVEL 17 5 5 The MCCK ignition system uses 4volt coil battery ignition to fire both spark plugs simultaneously The ignition system is shielded to prevent radio interference The ignition system is shown in Figure 15 MAINTENANCE Oper
12. bilge blower Diode CR3 between B and BB is a discharge diode to protect other components in the control from inductive voltage when the bilge blower is turned off BILGE BLOWER ON BILGE BLOWER 12 SAMP MAX Y KT 51 AUTO o modd AM FIGURE 36 37 ENGINE CRANK CIRCUIT When Time Delay A2K contacts 1 3 close Current flows to energize the Start Stop Relay Kj The contacts ENGINE CRANK close the circuit through contacts 1 4 to energize Sor BLOWER l Start Solenoid Relay The main contact of Ke closes 12V SAMP MA to supply battery power to the cranking windings the Tara generator The auxiliary contact BAT I of Start Solenoid closes the circuit to the Solenoid C1 C2 on the thermo magnetic choke mounted on the FIGURE 37 38 CRANKING LIMITER When the Start Solenoid Relay picks up contact I closes to supply battery power through Diode CR through the Resistor R3 to the heater on the Time Delay Relay 7 320B104 Emergency Relay If the electric plant does not start within approximately 45 seconds this relay opens its contacts to the control circuit and shuts the unit down Diode CR2 serves as a blocking diode to prevent current flow to the choke control during a low oil pressure condi tion IGNITION When Relay energizes its contacts close to supply battery power to Relay
13. for choke adjustment To adjust the choke loosen the screw on the choke body and rotate the cover assembly ey 15 Adjustment Gasoline Carburetor The carburetor should be adjusted in two steps first the load adjustment and then the idle adjustment See Figures 11 and 12 NOTE f the carburetor 15 completely out of adjustment so the engine won t open both needle valves 1 to 1 1 2 turns off their seats to permit starting Don t force the needle valves against their seats This will bend the needle Before adjusting the carburetor be sure the ignition system is working properly and the governor is adjusted Then allow the engine to warm up 1 Apply a full load to the engine Carefully turn the main adjustment in until speed drops slightly below normal Then turn the needle out until speed returns to normal 2 With no engine load tum the idle adjustment out until the engine speed drops slightly below normal Then turn the needle in until speed returns to normal ALTERNATE METHOD USE WHEN THERE IS NO LOAD ADJUSTMENT POSSIBLE 1 Start the engine and allow it to warm up Push in on the governor mechanism to slow the engine down to about 400 to 500 rpm 2 Set the idle adjustment screw foi even operation so the engine is firing on all cylinders and running smoothly 3 Release the governor mechanism to allow the engine to accelerate The engine should accelerate evenly and without a lag If not adj
14. load sensor amplifier The voltage should read 2 to 3 VAC Use 20 000 ohm Voltmeter to minimize error Voltage from ground to the transistor side of Resistor should measure 0 6 to 0 7 VDC Voltage across A1CR should read 5 to 14 VDC When relay operates contacts 4 6 open Remove jumper from Switch 61 3 Control O Matic starts plant automatically under load but slows down or stops as soon as contactor picks up a Recheck adjustment Recheck size and type of load Minimum require ments a 40 watt incandescent lamp load or a 425 watt heater load of contactor Pick Up Re sistor Ro Apply a load and help contactor pick up and hold in as the plant starts If this corrects the problem reduce the resistance of Ro Apply load and hold the contactor to delay pickup If this helps increase the resistance setting of Resistor R2 Move toggle switch to the OFF position Connect a jumper from Terminal 8 of Relay to ground terminal Move toggle switch to the AUTO position The plant should start and run Apply load such as 100W lamp then remove the jumper while the plant is running with the switch in the AUTO position If the plant stops place the toggle switch to OFF jumper the two outside terminals of the toggle switch and place in AUTO position to restart While the plant is running with a 100 watt minimum load measure _the voltage on the load sensor am
15. mark on the flywheel and the TC mark on the gear cover are in line This should place the left piston at the top of its compression stroke the position it must be in to get proper valve adjustment for the left cylinder Clearances are shown in Figure 18 For each valve the thinner gauge minimum should pass freely between the valve stem and valve tappet but the thicker gauge maximum should not To adjust valve clearance turn adjusting screw as needed to obtain the right clearance The screw is self locking To adjust the valves on the right cylinder crank the engine over one complete revolution and again line up the mark on the flywheel and the TC mark on the gear cover Then follow the adjustment given for the valves of the left cylinder 23 ENGINE DISASSEMBLY GEAR COVER After removing the mounting screws tap the gear cover gently with a soft faced hammer to loosen it When in stalling the gear cover make sure the pin in the gear cover engages the metal lined smoothest hole in the governor cup Turn the governor cup so the metal lined hole is at 3 o clock Figure 19 The smooth side of the governor yoke must ride against the governor cup Check that the bearing ball is in position Figure 19 Turn the governor arn and shaft clockwise as far as possible and hold in this position until the gear cover is installed flush against the crankcase careful not to damage the gear cover oil seal Adjust the roll
16. obligations to original user This warranty shall not apply to any of the Manufacturer s products which must be replaced because of normal wear which have been subject to misuse negligence or accident or which shali have been repaired or altered outside of the Manufacturer s factory unless authorized by the Manufacturer Manufacturer shall not be liable for loss damage or expense directly or indirectly from the use of its product from any cause The above warranty supersedes and is in lieu of all other warranties expressed or implied and of all other liabilities or obligations on part of Manufacturer No person agent or dealer is authorized to give any warranties on behalf of the Manufacturer nor to assume for the Manufacturer any other liability connection with any of its products unless made in writing and signed by an officer of the Manufacturer SPECIFICATIONS Nominal dimension of plant Heights der Width a toad Length 2 45 94 Rh rmn Number cylinders veda Displacement cubic dt eus Cylinder bore Piston Qa RPM for60cycdle RPM for 50cycle rm Compression ratio QS nap Battery voltage Battery size SAE group Amp hr SAE rating 20hr Hn Battery charge rate amperes Ventilation
17. part of the armature shaft The test prods must make good electrical contact The test lamp should not glow the test lamp glows the DC winding or the commutator is grounded To test AC windings place one test prod on one of the collector rings and the other test prod on the armature shaft If the test lamp glows AC windings or a collector rng is grounded Replace grounded armatures Armature Open Armature windings may be tested for an open circuit without removing the armature Testing the DC winding requites removal and the use of an armature growler Figure 32 test windings lift or remove all brushes Use test lamp set Place one test prod on each of the collector tings If the lamp does not glow windings are open circuited To test the DC windings place the armature in a growler Then pass a smooth steel strip across the commutator segments Repeat all around the commutator At some point around the commutator a spark should occur as the strip contacts two adjacent segments Rotate the armature slightly and repeat the test Continue until a spark is RIGHT WAY WRONG WAY TO GRIND TO GRIND TEETH TEETH MICA GRIND BLADE TO _ WIDTH OF MICA COMMUTATOR BARS COMMUTATOR BARS WORN BELOW LEVEL OF MICA SEPARATORS CAUSE SPARKING JUMPING NOISY BRUSHES FIGURE 31 UNDERCUTTING COMMUTATOR MICA obtained between all adjacent segments no spark is obtained at some poin
18. plug Remove clean and inspect the plugs at regular intervals If they are in good shape they can be cleaned on a commercial plug cleaner and regapped The spark plug gap should be set at 025 for gasoline fuel When spark plug electrodes become excessively worn or if the plugs are damaged replace them When replacing or reinstalling spark plugs always install new gaskets 19 GOVERNOR SYSTEM GOVERNOR AND BOOSTER The governor and booster control engine speed speed adjustment requires adjusting both devices General Before making governor adjustments run the plant 15 minutes under light load to reach normal operating temperature If the governor is completely out of adjust ment make a preliminary adjustment at no load to attain safe voltage operating range Engine speed determines voltage and frequency Increasing the engine speed increases the generator voltage and frequency Decreasing the engine speed lowers the gen erator voltage and frequency accurate voltmeter or THROTTLE STOP SCREW THIS DISTANCE 1 32 T AT NO LOAD STOP PIN CARBURETOR THROTTLE ARM THIS DISTANCE DETERMINES SENSITIVITY SS 1 MoRE SENSITIVE LESS 1 SENSITIVE SPEED e INCREASE DECREASE GOVERNOR ADJUSTMENT frequency meter preferably both should be connected to the generator output in order to correctly adjust the governor of the AC plant small s
19. socket Pin 8 to ground The circuit should 48 show a high resistance approximately 20 000 ohms with positive on Pin 8 and will show a low resistance approximately 20ohms with negative to Pin 8 If this check indicates continuity in both directions unsolder one end of Zener Diode AjCRg and repeat same test If resistance increases to the expected values the zener diode has shorted To verify this check con tinuity in both directions on the zener diode itself If resistance does not increase with the zener diode disconnected check the transistor for a short from the collector to the emitter 5 Bilge Blower Control circuit does not function at all a Check the 6 1 4 amp fuse AgF1 6 Blower circuit is energized continuously and electric 44 plant won t crank Check heater element of thermal relay for open Circuit or a poor connection which may prevent relay from heating up enough to switch 7 Blower circuit is not energized but plant starts after a 2 to 6 minute delay Check the blower operation by placing a jumper from Terminal BB to ground Check the transistor Turn On circuit Measure the voltage across Terminals 1 2 of 2 to ground This voltage should be 0 7V or less while the bilge blower is enetgized Measure the voltage from Terminal 2 of 2 to ground This voltage should be equal to the battery voltage Check the voltage across Resistor AgR2 This voltage shou
20. spring tension overcomes the pull of the diaphragm and tension is put on the booster external spring This tension helps the regular governor spring in its function by causing a slight increase in engine speed as the load is increased binding in the governor shaft bearings ball joint or carburetor throttle assembly will cause erratic governor action or alternate increase and decrease in speed hunting A lean carburetor adjustment may also cause hunting Springs of all kinds have a tendency to lose their calibrated tension through fatigue after long usage If all governor and carburetor adjustments are properly made and governor action is still erratic install a new spring and adjust ADJUSTMENT 1 Adjust the carburetor main jet for best fuel mixture while operating the plant with a full rated load 2 Adjust the carburetor idle needle under no load condition 3 Adjust the length of governor linkage 4 Check the governor linkage and throttle shaft for binding or excessive looseness 5 Adjust the governor spring tension for rated speed at no load operation with booster disconnected or held inoperative Adjust the governor sensitivity Recheck the speed adjustment Set the carburetor throttle stop screw Set the vacuum speed booster GOVERNOR The governor and speed booster control engine speed Figure 17 Rated speed and voltage appear on the nameplate The engine speed on 4 pole generating plant equals t
21. the following pages Accompanying the description of each function is a Schematic drawing with current flow shown as bold lines on the drawing pictorial wiring diagram appears as Figure 33 on the next page Throughout the text are references to various components electrical devices terminal positions and current flow When reading through the text follow current flow on the schematics and locate _telative positions of electrical devices and terminal positions on Figure 33 This will provide a more compre hensive understanding of the operation of the Control O Matic 33 34 FIGURE 33 The control must operate with a negative ground Connect battery with correct polarity Switch S1 is a three position switch Center position is OFF Moving the switch handle to the RUN position bypasses Relay K4 contact 7 6 to energize the Bilge Blower Control which goes through its control cycle before the electric plant cranks and runs By moving the 51 switch handle to AUTO the Control O Matic starts the plant which will run as long as a load demand prevails In this case the load must be at least a 40 watt incandes cent lamp LOAD DEMAND When the plant is in AUTOMATIC Mode and a 40ewatt lamp or larger is turned on a load demand exists Battery current flows through Switch S1 Relay Coil K4 2 3 contacts Load Terminal A through the load to ground and back to the battery to energize Rela
22. the worn parts or install a new pump Pump Assembly 1 Soak the diaphragm in fuel then insert the diaphragm spring and soaked diaphragm into the pump body 2 Insert the link and rocker arm into the body hook it over the diaphragm pull rod Align the rocker arm with the tocker arm pin hole then drive in the pin 3 Compress the rocker spring and install between the body and rocker arm 4 Insert the valve cages gaskets and valve cover plate Position the inlet valve with spring showing and the outlet valve with the spring in the cover recess 5 Assemble the cover to the body with scribed marks aligned Install screws but do not tighten 6 Push the rocker arm to full stroke and hold in this position to flex the diaphragm IMPORTANT The diaphragm must be flexed or it will deliver too much fuel pressure Tighten cover screws alternately and securely before releasing the rocker arm 7 Install the pump and repeat pressure test THERMO MAGNETIC CHOKE This choke uses a strip heating element and heat sen sitive bimetal spring to control the choke blade position A solenoid actuated during engine cranking closes the choke all or part way depending on ambient temperature The bimetal is factory calibrated to position the choke to the proper opening under any ambient condition Disassembly and Repair If the choke does not operate or will not maintain its adjustment disassemble it for repair If it
23. will not close check for binding incorrect adjustment or incorrect assembly of the coil If it will not open after the plant starts check for heating The choke should be warm to the touch within a minute or two of plant starting Adjustment must be made with the bimetal at ambient temperature Do not attempt adjustments until the engine has been shut down for at least one hour Remove the flame arrester and adapter to expose the carburetor throat Loosen the screw which secures the choke body assembly Refer to Figure 8 for correct choke setting according to temperature Use drill r the shank of a drill bit to measure the choke opening For a richer mixture turn the choke body clockwise to lean it turn counterclockwise Tighten the screw that secures the choke body Repair of Choke Heating If the choke will not heat properly check for a broken heater wire high resistance connections or broken lead wires to the bimetal and heater assembly With the element at room temperature check the heater resistance with an ohmmeter The r sistance should be about 30 6 to 37 4 ohms for a 12 volt system If the heater is defective install a new one When the START button is engaged the solenoid should cause the spring loaded armature to contact the solenoid core If this does not occur check for broken lead wires or a defective solenoid coil There must be slack in the lead wires between the choke body 13 A
24. 010 020 030 and 040 P S Piston rings are available in 010 020 030 and 040 0 5 Use standard rings on a 005 oversize piston If the cylinder is not being reconditioned but new piston rings are being installed remove any ridge which may have become formed at the top of piston ring travel in the cylinder bore engine may be fitted at the factory with 005 oversize pistons and is so indicated by a letter E following the engine serial number stamped on the cylinder block and on the unit nameplate The standard cylinder bore size appears in the Table of Clearances FLYWHEEL To remove the flywheel turn the flywheel mounting screw outward about two turns Use a screwdriver behind the flywheel to take up the crankshaft end play Then strike 28 a sharp endwise blow on the head of the cap screw with a heavy soft faced hammer to loosen A suitable puller with claws or with bolts to agree with flywheel may be used to pull the flywheel Always use a steel key for mounting the flywheel CYLINDER HEADS Torque cylinder heads at room temperature according to Figure 28 At some later time after the engine has been operated so it reaches normal hot temperature and cooled to room temperature the cylinder head bolts should be retorqued to the original specified torque This retightening should be done before the engine has been run fifty operating hours CYLINDER HEAD FIGURE 28 CY
25. 2 Specific type A AUTOMATIC type Demand Control series HA is mounted on plant E ELECTRIC start type Electric starting at the plant only R REMOTE type Electric starting For permanent installation can be connected to optional accessory equipment for remote or automatic control of starting and stopping 3 Factory code for optional equipment 4 Specification Spec letter advances when factory makes production modifications For service information refer to HA series Automatic Demand Control Manual number 907 8 replacements for defective parts shail constitute fulfillment TYPICAL MODEL MCCK MANUFACTURER S WARRANTY The Manufacturer warrants to the original user that each product of its manufacture is free defects in materiel and factory workmanship if properly installed serviced and operated under normal conditions according to the Manu facturer s instructions Manufacturer s obligation under this warranty is limited to correcting without charge at its factory any part or parts thereof which shall be returned to its factory or one of its Authorized Service Stations transportation charges prepaid within one year after being put into service by the original user and which upon examination shall disclose to the Manufacturer s satisfaction to have been originally defective Correction of such defects by repair to or supplying of of all
26. 27 0 00157 0 0001 0 010 1 9992 1 6252 3 249 Cylinder Head Bolts Fuel Pump Mounting Screws Approximately Flywheel Mounting Screws Intake Manifold Screws Exhaust Manifold Screws Spark Plugs 449 459 Thumb Push Fit 0 0207 0 0187 0 0257 _ 25 BTC 7 Pints ANCES AND TORQUES Maximum 0 013 0 0025 0 004 3 64 0 00387 0 012 0 0030 0 0023 0 016 0 003 0 005 0 0035 0 0006 0 023 2 0007 1 6260 3 2507 29 31 10 15 3540 15 20 15 20 25 30 TROUBLE SHOOTING POSSIBLE CAUSE REMEDY ENGINE CRANKS TOO STIFFLY Too heavy oil in crankcase Engine seized Drain and fill with lighter oil Disassemble and repair ENGINE CRANKS TOO SLOWLY WHEN CRANKED ELECTRICALLY Discharged or defective battery Faulty field rectifier Corroded or loose battery terminals or connections Brushes worn excessively or making poor contact Short circuit in generator or load circuit Dirty or corroded points in start solenoid switch Charge or replace Replace rectifier Clean corroded terminals Replace cable if necessary Replace brushes and or clean commutator Repair or replace parts necessary Disconnect load Replace switch ENGINE WILL NOT START WHEN CRANKED Out of fuel Faulty ignition Lack of fuel or faulty carburetion Clogged fuel filter Cyl
27. 5 and the ignition circuits Cur rent flows through the Ignition Resistor 1 the High Water Temperature Switch 2 the primary of the ignition coil and through the breaker points S3 to ground This supplies ignition power to spark plugs E1 and E CRANKING LIMITER AND IGNITION TO BILGE BLOWER 12 MAX 4 6 98 y 0246 MV 51 AUTO o OFF ind SEE 4 im y 52 53 FIGURE 38 39 START DISCONNECT CHOKE HEATER AND BATTERY CHARGE When the electric plant starts power from the armature supplied through Lead energizes Relay K2 which is the Start Disconnect Relay 307B642 Relay K2 contacts 1 4 open the Start Relay coil circuit Relay de energizes opening its contacts to disconnect the cranking circuit and Choke Solenoid circuit Relay contacts 3 9 close the circuit to the Bi metal Heater of the thermo magnetic choke The Bi metal heats to open the choke for normal running as the engine warms up Relay Ko contacts 3 9 also close the circuit to Time Delay Relay through Low Oil Pressure Switch S4 and Resistor R4 If oil pressure switch S4 does not open Time Delay Relay Ky operates to open the normally closed contact to shut down the plant Wait one minute then push to reset When the generator comes up to speed it bat
28. ASURE ENDPLAY HERE Refer to table of clearances FIGURE 23 CRANKSHAFT ENDPLAY 26 and after installation bearing zs cannot be fitted with an available precision type undersize bearing refinish it to the next undersize If worn rod journal cannot be fitted by installing new bearing inserts forged rod then refinish it to take the corresponding undersize rod or bearing insert available Whenever making major engine repairs always inspect the drilled crankshaft passages Clean any foreign material to assure proper connecting rod lubrication BEARINGS Camshaft or crankshaft bearing removal requires complete engine disassembly Use a press or suitable drive plug to remove the bearings Support the casting to avoid distortion or bearing bore damage during removal and installation Oil the bearings to reduce friction before See Figure 24 New crankshaft main bearings are a precision type which do not require line reaming or line boring after installation They are available in standard size 002 010 020 030 undersize Expand the bearing bore by placing the casting in hot water or in an oven heated to 200 F If a torch is used apply only a little heat If practical cool the precision bearing to shrink it Align the oil hole s in the bearing with the oil hole s in the bearing bore oil passage must be at least 1 2 open cold oiled precision bearing should require only light
29. CENTER PIN SNAP RING FIGURE 20 GOVERNOR CUP GOVERNOR Le GOVERNOR ARM GOVERNOR SHAFT GOVERNOR SHAFT YOKE Smooth Side Toward Cup OIL SEAL FEELER WILL ENTER HOLE 1 2 BALL HAS FALLEN OUT FIGURE 19 GEAR COVER ASSEMBLY 24 TIMING GEARS 2 5 If replacement of either the crankshaft gear or the camshaft gear becomes necessary always install two new gears To remove the crankshaft gear first remove the snap ting then attach the gear pulling ring Onan tool no 420A248 using two 10 32 screws Tighten the screws alternately until both are tight Attach a gear puller to the puller ring and proceed to remove the gear Figure 21 The camshaft gear is pressed on and keyed to the camshaft The camshaft and gear must be removed as an assembly after first removing the crankshaft gear lock ring and washer Before removing the camshaft and gear assembly remove the cylinder head valve assemblies and breaker point plunger Remove the fuel pump and tappets After removing the governor cup assembly from the gear the camshaft may be pressed out of the gear by use of a hollow tool or pipe which will fit over the camshaft center pin Do not press on the center pin The governor ball spacer is a press fit to the camshaft gear When pressing a camshaft gear onto the camshaft be sure the gear is started straight and that the key is properly in place Install the governor cup assembly before installing the
30. INE PUMP M EXCHANGER INSIDE FITTING PUMP TO HEAT EXCHANGER _ REAR FITTING TO HEAT EXCHANGER RAW WATER FRESH WATER COOLING SYSTEM for leaks inspection of the rubber pump impeller and flushing and cleaning The rubber impeller because of continuous flexing will in time need replacement If the impeller fails after short service usually under 500hours check for possible defects such as severe pitting or abrasion caused by dirt in the cooling system The cooling system must be kept clean to function properly Scale reduces heat transfer and restricts water flow Flush the system at least once a year and more often if operation indicates clogged passages pump wear or overheating flush the engine remove the thermostats Figure 2 and the water pump cover Partially restrict the pump opening so the cylinder block fills with water Attach the flushing gun nozzle to the thermostat opening and fill the block with water then apply air pressure Repeat the process until water coming from the block is clean EXHAUST ELBOW 713 MANIFOLD 3 LP SS TT TO HEAT EXCHANGER PUMP OIL PRESSURE GAGE LOW PRESSURE CUT OFF SWITCH BELT HEAT EXCHANGER PUMP FIGURE ENGINE COOLING SYSTEM HEAT EXCHANGER MODELS THERMOSTAT THERMOSTAT CYLINDER HEAD fj onam PLUG FIGURE 2 THERMOSTAT REMOVAL TESTING The cooling system can be te
31. LAMP FOR TESTING FOR OPEN CIRCUITS AND GROUNDS USE 3 OR 4 CANDLEPOWER BULB AC SOURCE FIGURE 32 ARMATURE TESTING 31 Slide armature over the through stud and onto the crankshaft being careful not to let the weight of the armature rest the through stud Install baffle ring when used Assemble generator through studs to the adapter with required torque CAUTION NOT tighten the armature or rotor through stud before mounting the frame and bearing support If this procedure is not followed misalignment may occur shortening the life of the rear main and outboard bearings Also cranking torque re quirements could be doubled resulting in damage to the commutator and DC brushes 32 8 9 10 Install the frame and bearing support Tighten frame to required torque NOW torque down the armature through stud nut Because you have tightened the frame and bearing support before tightening the armature you have the armature and frame in alignment Tap the bearing support in the horizontal and vertical plane with a lead hammer to relieve stresses on the components and then recheck the torque i CONTROL SYSTEM The plant control system regulates starting stopping battery charging and provides a means of emergency automatic stopping Control system defects can best be analyzed with the proper wiring diagram l When using Onan wiring diagrams remembe
32. LINDER HEAD BOLT TORQUE SEQUENCE GENERATOR revolving armature generator is used in MCCK generating plants It is a 4 pole self excited generator with inherent regulation generator serves as a starting motor and furnishes DC current to recharge the batteries during operation The generator field contains shunt windings and series windings a few of heavy wire wound on the same forms as the shunt windings series windings act as the starting motor field shunt windings are the working field which produce the magnetic field in which the armature turns to produce useful output A rectifier in series with the shunt field mounted on the generator frame provides increased engine cranking torque during plant starting The generator armature contains both AC output windings and DC windings to supply the field and battery charging circuit The generator is mounted to the engine through the engine to generator adapter and the armature is directly connected a tapered fit to the crankshaft The outboard end of the generator tides on a ball bearing housed in the end bell Because of its construction the generator cannot be removed as a unit Generator leads are marked with metal tags for identifi cation Lead and terminal marking codes are noted on the plant wiring diagrams Generators need little care other than a periodic check of brushes commutator and collector rings
33. MBIENT TEMP CF pe 3 3 CHOKE OPENING Inches 1 8 ce TO MANUAL CHOKE OPENING m7 CHOKE CONTROL See text j KNOB ON OUTSIDE OF BLOWER HOUSING pete ABBURETOR ge LOOSEN THIS 2 SCREW AND gt 5 4 M lt e ENTIRE COVER ASSEMBLY HAND CHOKE FIGURE 8 THERMO MAGNETIC CHOKE SETTINGS AND ADJUSTMENTS w WASHER 17 64 1 0 x 5 8 O D x 1 16 PLATE ASHER INSULATOR LEVER LIMIT BODY CHOKE SPRING DY z PLATE CHOKE MOUNTING D ARMATURE 4 m RING RETAINING ASSY l CORE TA SOLENOID c me BIMETAL AND SOLENOID HEATER ASSY FRAME SOLENOID DA TERMINAL GROUND fii LEAD GROUND WASHER SHAKEPROOF lt gt WASHER 24 64 1 0 x 9 16 0 0 x 1 16 LED NUT 5 16 187 7 FIGURE 9 THERMO MAGNETIC CHOKE ASSEMBLY and the bimetal and heater assembly The solenoid coil Fuel enters the carburetor through the fuel inlet valve should have a resistance of 2 09 to 2 31 ohms in a 12 volt Figure 10 and passes into the float chamber fuel system level in the bowl is regulated by the float which opens is 2 and closes the inlet valve Assembly Refer to Figure 9 When assembling the thermo magnetic The idle circuit Figure 11 supplies fuel during no load choke connect the bimetal and heater assembly as follows operation and for light loads The throttle plate is nearly 1
34. Required cfm 1609000 Generator ee ew ee ees ie Combustion Output rated at unity power factor load Rating output in watts 50 AC Marine Service 60cycle AC Marine Service AC voltage regulation in t AC frequency regulation in Revolving armature type generator 120 240volt single phase model xecodnactible 5 Rotating type exciter 29 9 16 for 4MCCK 3 eves ene 2 t LI sa ee 9 3 4 5 9 9 8 one s o 4 3 9 9 9 5 94 9 ne LI eon meee we oe ae ee o9 9 5 ae se eae oe ee 9 9 mre ee ee ee ee oe oe ee aoe 9 509 9 ese eee 3 oem on n e 9 9 4 9 ee ese 924 eves ee eee 4 s eee ae we ee s ae c n eee ere eii ius CU oe eee PS oe x esc t Model Series 4MCCK 24 22 28 2 50 3 1 4 3 1800 1500 71 12V two in series 105 2 3 Low 5 8 High 75 32 n 1 phase 3500 4000 3 5 Yes Yes Yes 605 24 22 33 2 50 34 4 3 1800 1500 7 1 12V two in series 105 2 3 Low 5 8 High 75
35. The lead tagged goes to the ground terminal on the closed at no load creating High intake YERDIM Sail solenoid The pressure difference between the manifold and float 4 chamber causes fuel to flow through the idle circuit The 2 The lead tagged H goes to either of the terminals pressure difference draws fuel up through the hollow on the solenoid core center of the idle transfer tube and then through passages FN in the carburetor body to the idle port and is controlled CARBURETOR sca YT re by the idle needle As the throttle is opened to increase e gasoline carburetor is a horizontal draft type ower the idle transfer port is uncovered and additional consists of three major sections the bowl and float idle El is added during ae transfer from idle to main jet circuit and load circuit operation Figure 12 shows the load circuit 14 EL INLET LVE SEAT mel Se p 4 CARBURETOR jBODY FUEL INLET VALVE CARBURETOR FLOAT METERING F1 WELL AIN IDLE JET OPERATING FIGURE 11 CARBURETOR IDLE CIRCUIT When the load increases the engine governor opens the throttle to maintain speed With the throttle open the manifold vacuum decreases and the idle circuit becomes less effective the air flow increases reduced pressure is created at the venturi narrow section of the carburetor throat The difference in pressure between the venturi and fu
36. This pump is not to be used in a closed system ENS fresh water such as keel cooling High Water Temperature Cut off Switch This normally closed switch Figure 1 senses water temperature in the engine cooling jacket The switch opens breaking the circuit to the coil primary when the water temperature reaches approximately 200 F and closes when the temper ature drops below approximately 160 F HEAT EXCHANGER COOLING Optional Figure 4 heat exchanger cooling is available factory installed or as a kit for customer installation complete heat exchanger installation contains two water systems a fresh water system and a raw water system The fresh water system continuously re circulates fresh water through the water jacket exhaust manifold centrifugal pump and one side of the heat exchanger raw water system uses the engine mounted rubber impeller pump to draw and circulate sea water through the heat exchanger and then discharges it CAUTION When planning to install a heat exchanger other than Onan approved or any keel cooler consult the factory or an Onan distributor To ensure an adequate installation the engine cooling system must be modified agt FRESH WATER IN PRESSURE 7 RAW WATER IN TO ENGINE PUMP RAW WATER OUT 5 WATER TO HEAT OUT EXCHANGER FIGURE 4 HEAT EXCHANGER Maintenance Maintain the fresh water system the same as an automotive r
37. UN TOO SLOWLY AND OVERHEAT AT FAR END OF LINE BUT OK NEAR THE PLANT Too small line wire used for load and distance Install larger or extra wires or reduce load NOISY BRUSHES High mica between bars of commutator Undercut mica EXCESSIVE ARCING OF BRUSHES Rough commutator or rings Dirty commutator or rings Brushes not seating pro perly Open circuit in atmature Brush rig out of position Turn down Clean Sand to a good seat or reduce load until worn in Install a new armature Line up properly thermostats The cooling system is a pressure circulating open type system that uses raw liquid coolant such as fresh water or sea water NOTE Factory installed heat exchangers for a closed type system are available as an optional feature In a raw water cooling system water enters the pump located the front right side of the engine The pump delivers water to the cylinder jacket and it flows through the jacket and out openings in the cylinder heads controlled For engine warm up with thermostats closed a by pass from the cylinder block to the thermostat allows water flow From the thermostat water passes through the water cooled exhaust manifold and out the engine cooling system Figure 1 shows the cooling system operation MAINTENANCE Cooling system maintenance includes periodic inspection HIGH WATER TEMPERATURE SWITCH RAW WATER Ng ENG
38. adiator cooling system Clean and flush once a year and use anti freeze if there is danger of freezing Use a rust inhibitor in the closed water system For raw water systems check periodically for air leaks tubber impeller wear damage or restricted lines Cleaning To clean the fresh water system drain and fill with radiator cleaner When chemical cleaning is done always flush the cooling system to wash out deposits loosened by the chemical cleaning Flush the engine water jacket previously discussed First remove the water outlet hose from the engine water jacket to the heat exchanger Flush both the fresh water side and the raw water side of the heat exchanger Remove the rubber impeller pump cover to flush the raw water side Also flush the water cooled exhaust manifold When flushing is completed check the system thoroughly for leaks Centrifugal Pump Repair The centrifugal fresh water pump is mounted on the heat exchanger bracket If it leaks or the bearings require replacement disassemble as follows and replace the worn components 1 Remove the water inlet from the pump and the six screws holding the end cover to the pump 2 Unscrew the impeller from the shaft counterclockwise when facing the impeller 3 Remove the pump body by unscrewing the single cap screw that clamps the pump body to the pedestal 4 Remove the retaining ring and drive the bearing assembly from the pedestal 5 To remove the wat
39. ading is above maximum the diaphragm is probably too tight or the diaphragm spring too strong Fuel seeping under the diaphragm retainer nut and between the diaphragm layers causing a bulge in the diaphragm Overhaul the pump if this occurs Low pressure with little or no pressure leak after pumping stops indicates a weak or broken spring or worn linkage In most cases the pump should be replaced Removal and Repair 1 Remove the pump inlet outlet and the two cap screws holding the pump to the engine Lift the pump from the engine 2 Notch the pump cover and body with a file so they can be assembled in the same relative position Then remove the screws holding them together 3 Tap the body with a screwdriver to separate the two parts Do not pry them apart it will damage the diaphragm 4 Remove the screws holding the valve p to the cover and lift out the valve and cage assemblies Drive out the rocker arm hinge pin Remove the rocker arm spring and 1 Lift out the diaphragm assembly and spring DC Fuel pump failure is usually due to a leaking dia phragm valv or valve gasket A kit is available for replacement of these parts Because the extent of wear cannot be easily detected replace all parts in the kit If the diaphragm is broken or leaks check for diluted crankcase oil Occasionally failure is due to a broken or weak spring wear the linkage this case replace
40. ating with a weak spark is detrimental to the generating plant Periodic maintenance should include 1 Checking ignition breaker point gap 2 Gapping and cleaning spark plugs 3 Inspecting low and high tension cables 4 Checking the ignition timing Timing Ignition timing procedure is the same for electric start and remote start plants with 12 volt battery ignition The spark advance is 25 before top Timing is stamped the cylinder block near the breaker box Set timing as follows 1 Remove the cover from the breaker box If timing is out of adjustment attain an approximate setting by loosening the mounting screws and shifting the breaker box to align the witness marks on the cylinder block and breaker box 2 Crank the engine over slowly by hand in the dissection of crankshaft rotation until the witness mark on flywheel and the TC mark on the gear cover are exactly in line see Figure 16 SPARK ____ IGNITION BREAKER POINTS uUa LII FEED HEUS CONDENSER HIGH WATER TEMPERATURE CUT OFF SWITCH IGNITION RESISTOR TO CONTROL BOX CONNECTION FIGURE IS IGNITION SYSTEM 18 Adjust the ignition breaker point width to 0 020 at full separation Turn flywheel to the left against crankshaft rotation until the timing mark is about two inches past the 25 mark on the gear cover Turn flywheel slowly to the right and note if the ignition points just separate whe
41. ble Install a new pump assembly if required OIL PRESSURE RELIEF VALVE ADJUSTMENT Oil pressure can be easily adjusted by means of the slotted stud and lock nut located just below the governor linkage Oil pressure at operating temperature should be between 25 and 40 pounds increase oil pressure loosen the MOUNTING FACE OF GEAR COVER THIS SURFACE SHOULD BE CLEANED OF ALL OLD SEALING COM POUND BEFORE INSTAL LING SEAL SHOULDER THIS SURFACE SHOULD BE CLEANED OF ALL OLD SEALING COM 877 POUND BEFORE INSTAL DRIVE OR PRESS OIL SEAL TO SHOULDER OF THE PLATE BORE REAR BEARING PLATE OiL SEAL DE 2 TORT REFER TO INSTRUCTIONS FOR PROPER SETTING OF THE OIL PRESSURE RELIEF VALVE ADJUSTMENT SCREW FIGURE 27 OIL PRESSURE RELIEF VALVE ADJUSTMENT 27 lock nut and turn the stud in decrease pressure by loosen ing the lock nut and turning the stud out Always tighten the lock nut after making an adjustment Low oil pressure may point to worn or poorly adjusted main or connecting rod bearings weak or broken by pass Spring defective gauge or a poor adjustment Always check the oil pressure gauge before making other tests CYLINDER The cylinder wears very little in normal service If through improper lubrication or accident the cylinder wall is Scored or worn badly the cylinder may be rebored and honed to accommodate an oversize piston and rings Pistons are available in
42. camshaft and gear in the engine Each timing gear is stamped with an O mark 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 assembly be sure that the thrust washer is properly in place behind the camshaft gear Then install the crankshaft retaining washer and lock ring PISTONS AND RINGS Piston and connecting rod assemblies are removed from the top The pistons have two compression rings and one oil control ring with expander Inspect each piston Piston ring grooves should be cleaned of any carbon deposits and the oil return slots in the lower groove must be open If pistons are badly scored loose the cylinders have badly worn ring grooves and are loose on the piston pins so that 002 oversize piston pins will not correct it install new pistons Handle pistons carefully COINCIDE WHEN IN STALLING TIMING GEARS Conformatic pistons are designed for a very close fit in the bore A slot on opposite sides of the piston behind the oil control ring permits oil return and allows for expansion The piston is interchangeable as to which side should be nearer the oil base Inspect rings carefully for fit in grooves tension and seating on cylinder walls Install new rings where there is any doubt about the condition of the old rings Figure 22 shows following step Before installing new rings
43. cuit Start the electric plant Sense when all load is removed Stop the electric plant mo eo A sheet metal enclosure approximately 12 5 8 wide 7 5 8 deep and 6 high houses the Control O Matic The Control O Matic mounts on top of the electric plant with its front panel facing the generator end of the plant The front panel holds the charge ammeter emergency relay and toggle switch unique hinge arrangement holds the front panel cover and chassis togethet The control box may be opened in a very limited space to expose al the relays for servicing HOW CONTROL O MATIC WORKS A three position toggle switch on the front panel selects one of three modes of operation RUN OFF and AUTO MATIC The Bilge Blower Control circuit in the Control O Matic delays cranking while it closes a 12 volt 5 amp circuit to operate the bilge blower When the three position toggle switch is moved to the RUN position the Bilge Blower Contro goes through its control cycle before the electric plant cranks and runs The electric plant stops when the three position switch is moved to the OFF position If the operator places the three position switch in the AUTOMATIC position the electric plant will crank and run on load demand after the Bilge Blower Control cycles The electric plant stops when all the load is removed from the AC line OPERATION OF CONTROL O MATIC Control O Matic operation is explained on
44. de the gear cover The bearing plate must be removed to replace its oil seal Drive the oil seal out from the inside Before installing seals fill the space between lips with a fibrous grease or stiff cup grease This will improve sealing When installing the gear cover oil seal tap the seal inward until it is 31 32 of an inch from the mounting face of the cover Install the thin open face seal 1 7 64inch from the mounting face of the cover THIN OPEN FACE SEAL DIMENSION IS 1 7 64 cup grease in space between seals improve seal GEAR COVER OIL SEAL LING SEAL GEAR COVER OIL SEAL CRANKCASE TURNED ON LEFT SIDE UNSCREW OIL PUMP _ FROM INTAKE CUP THIS POINT M To reassemble reverse the procedure FIGURE 26 OIL PUMP ASSEMBLY Use heavy fiber or When installing the bearing plate oil seal tap the seal into the bearing plate bore to b ttom against the shoulder in the plate bore Use a seal expander or place a piece of shim stock around the end of the crankshaft when replacing the bearing plate to avoid seal damage Remove the shim stock as soon as the plate is in place OIL PUMP _ remove the oil pump it is necessary to detach the intake cup assembly as shown in Figure 26 Inspect the pump thoroughly for worn parts and always prime it before installing Except for gaskets component parts are not available individually suction cup is availa
45. ec A only main nozzle is not removable beginning with Spec B Cleaning and Repair Soak all components thoroughly in a good carburetor cleaner following the cleaner manufac turer s instructions Clean all carbon from the carburetor bore especially in the area of the throttle valve Blow out the passages with compressed air If possible avoid using wire to clean out the passages Check the adjusting needles and nozzle for damage If the float is loaded with fuel or damaged replace The float should fit freely on its pin without binding Invert the catburetor body and measure the float level Figure 14 To adjust float level bend the small lip that the fuel inlet valve rides on Check the choke and throttle shafts for excessive side play and replace if necessary Don t remove the coating on the throttle shaft Assembly and Installation 1 10 11 12 13 Install the throttle shaft and valve using new screws Install as shown in Figure 12 with the bevel mated to the carburetor body On valve plates marked with the install with mark on side toward idle port when viewed from flange end of carburetor To center the valve back off the stop screw close the throttle lever and seat the valve by tapping it with a small screwdriver then tighten the two screws Install choke shaft and valve Center the valve in the same manner as the throttle valve Step 1 Always use new screws
46. een commutator bars rough commutator or col lector rings or from a deviation from neutral position in the adjustment of the brush rig Never bend the constant pressure type spring over the edge of its support See Figure 29 INSTALL BRUSHES WITH BEVELLED TOP SLANTING DOWN TOWARD SPRING HOLDER TO REMOVE BRUSH SPRING PRESS SPRING HOLDER DOWN AND OUT AS SHOWN IN BROKEN LINES FIGURE 29 BRUSH REPLACEMENT BRUSH RIG ALIGNMENT The brush rig must be aligned the neutral position it is not sparking occurs Normally the neutral position is identified by a chisel mark on the brush rig Figure 30 If the mark is lost or a new brush rig installed follow theseinstructions to find the neutral position 1 With the generator end cover and band removed to allow access to the rig connect a voltmeter across the DC terminals and start the unit and apply full rated load i 2 Loosen the brush rig mounting screws and rotate the rig to get the highest voltage 3 Rotate the rig in one direction until the voltmeter reading starts to decrease Mark this point 4 Repeat Step 3 in the other direction 5 Half the distance between the two marked points is the neutral position IMPORTANT Jf a voltmeter is not available use the above procedure but mark the point where arcing begins 29 ET LOCATION OF REFERENCE FIGURE 30 BRUSH RIG ALIGNMENT COLLECTOR RINGS If the collector rings beco
47. el bowl draws fuel up the main nozzle where it mixes with air from nozzle bleed holes before entering the carburetor The main adjusting needle controls fuel delivery IDLE JET R3 MAIN JET I FLOAT BOWL 1 VENT QU ee CHOKE 17 ws _ PLATE A737 CI MAIN JET OPERATING METERING WELL MAIN JET OPERATING FIGURE 12 CARBURETOR LOAD CIRCUIT During sudden increases in load the main nozzle cannot immediately deliver the increased fuel because of restric tion at the main adjusting needle prevent a lag when the load is suddenly increased a by pass around the outside of the nozzle delivers fuel until the main jet can catch up with the increased demand CHOKE Gasoline Fuel System Electric starting engines use an automatic electric choke Figure 5 manual starting engines use a hand choke Figure 8 electric element controls the automatic electric choke Before the engine starts the choke is partially closed When the engine has started the charging generator supplies current to the heating element which heats the bimetal coil opening the choke plate Adjustment Electric Choke Under normal operation adjust the choke so the distance measured between the choke plate and carburetor throat Figure 8 is as shown in the table with the engine cold Use the straight shank end of a drill bit to measure the gap The upturned silencer must be removed
48. er seal drive it out of the pump body Replace the worn components When replacing the water seal check the wear plate pressed into the impeller and replace it if necessary To assemble the pump reverse the disassembly procedure After assembly rotate pump shaft to see that impeller does not rub on pump body 11 FUEL SYSTEM MCCK engines use a gasoline carburetor fuel system to deliver a fuel air mixture to the combustion chamber FUEL Use a regular grade of gasoline One of the most important considerations is the fuel content of Tetra Ethyl Lead Premium fuels contain more lead than regular but the lead quantity also varies between brands of fuel In constant speed operation typical of generating plants deposit build up in combustion chambers is proportional to the amount of lead in the gasoline More lead means more deposits and the need for more frequent head removal for cleaning The interval between these cleanings can often be increased by changing fuel If fuel is stored for any great length of time it can oxidize and form gums the fuel becomes stale Onan recommends changing stored fuel as often as every three months especially where there is a great variation in temperatures CARBURETOR SILENCER REMOVED CRANKCASE BREATHER TUBE FUEL PUMP FIGURE 5 FUEL SYSTEM 12 MAINTENANCE Periodic maintenance should consist of cleaning re placing the fuel strainer fla
49. he frequency times 30 This means a 60 cycle plant must turn at 1800rpm The governor should not allow more than 2 1 2cycles change from no load to full load Linkage The length of the linkage connecting the governor arm of the throttle arm is adjusted by rotating the ball joint Adjust length so that with the engine stopped and the governor arm held in the closed throttle position the stop screw on the carburetor throttle lever is 1 32 from the stop pin This setting allows immediate control by the governor after starting and synchronizes travel of the governor arm and throttle shaft Speed Adjustment With the warmed up plant operating at no load and with the booster external spring disconnected adjust the governor spring tension Turn the speed adjust ing nut to obtain a voltage and speed reading within the limits shown Sensitivity Adjustment Check the voltage and speed with no load connected and then with a full load Adjust the 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 move the gov spring toward the governor shaft Adjusting for too much sensitivity will cause hunting To decrease sensitivity move the governor spring toward the outer end of the governor arm Too little sensitivity will result in too much difference in speed between no load and full load cond
50. ifier Ay This power is rectified by Diodes SEE jw LU 1 5 and A41CR4 This power is applied to the base of NOTE 4 the Transistor A1Q1 transistor switches on and RT c2 passes current through both coils on Relay keeping M it energized This relay remains energized as long as a minimum 4 watt incandescent lighting load is across the output terminals of Relay K3 STOP When the load is removed the flow of current through the power leads and the current produced in the secondary of Transformer drops to zero This switches the transistor off to de energize Relay The contacts open to break the ignition circuit and stop the engine MISCELLANEOUS To eliminate the five minute bilge blower time delay disconnect the lead from Terminal 1 on Time Delay and connect it to Terminal 3 FIGURE 40 CLYMAR INC N55 W13787 Lane i D Menomonee Falls Wisc 53051 414 781 0700 41 42 CONNECTING AUXILIARY RELAY TO CONTROL O MATIC This circuit allows a separate battery or power source to operate the bilge blower It also permits use of larger blowers with running currents in excess of 5 amperes The auxiliary relay should have a 12 VDC coil and contacts heavy enough to carry the current required by the bilge blower OPTIONAL AUX RELAY BILGE 0 BLOWER CONTROL O MATIC SWITCH OPTIONAL MANUAL SWITCH
51. ime ignition Reface seat or replace EXCESSIVE OIL CONSUMP TION LIGHT BLUE EXHAUST Poor compression Usually due to worn pistons rings or cylinders Oil leaks from oil base or connections does not cause smoky exhaust Oil too light or diluted Too large bearing clear ance Engine Refinish cylinders Install oversize pistons and rings Replace gaskets Tighten screws and connections Check breather valve Drain Fill with proper oil Replace bearings Refer to Engine Mistires at All Speeds POSSIBLE CAUSE REMEDY Clean adjust or replace breaker points spark plugs condenser etc ignition Drain excess oil Faulty ignition or time Too much oil BLACK SMOKY EXHAUST EXCESSIVE FUEL CONSUMP TION FOULING OF SPARK PLUG WITH BLACK SOOT POSSIBLE LACK OF POWER UNDER HEAVY LOAD Fuel mixture too rich See that choke opens pro perly Adjust jets and float level Choke not fully open See that choke opens pro perly Dirty flame arrester Clean Excessive crankcase pres sure Clean breather valve LIGHT POUNDING KNOCK Loose connecting rod Adjust clearance or replace Add oil Change if neces saty Drain Fill with proper oil Low oil supply Oil badly diluted Low oil pressure See Low Oil Pressure for remedies ENGINE STOPS UNEXPECTEDLY Empty fuel tank Fill Check ignition system and Defective ignition system repair
52. immediately when removed from hot water Replace the thermostat if it does not operate properly Water Pump The water pump is a positive displacement rubber impeller type located on the upper right corner of the engine Disassemble pump and repair according to Figure 3 and the following instructions 1 Remove the cover and gasket 2 Remove the impeller with pliers or by prying with screwdriver avoiding damage to the pump body install a new impeller align the driving flat surface the shaft flat surface bend blades nearest the cam and insert Do nof remove the factory coating of high analine oil from the impeller 3 Remove the retaining ring Then pry the seal assembly through the drain slots The factory uses Never Seez compound to install the bellows seal This may remain in the pump body An alternate sealer is suitable but not necessary Install with faces clean and oiled IMPORTANT Use engine lubricating oil on the inside and outside diameter of the seat ring on the new seal before installation The oil facilitates self alignment 4 To remove the bearing and shaft assembly drive out by striking the impeller end of the shaft using a brass or wood dowel Install by the same method striking the drive end of the shaft If the fit is tight strike the outer race only Lubricate the pump bore lightly 2 for ease of assembly PLUG PIPE PLUG PIPE 5 Torque screws 15 to 1741 lbs NOTE
53. inders flooded Poor fuel Poor compression Wrong ignition timing 6 Check fuel Clean adjust or replace breaker points spark plugs condenser etc or time ignition Check fuel system Clean adjust replace parts as necessary Replace Ground spark plug cables Crank engine with plugs removed Drain Fill with fresh fuel Tighten cylinder head bolts and spark plugs If still not corrected grind valves and or replace piston rings Re set breaker points or time ignition Open circuit short circuit POSSIBLE CAUSE REMEDY ENGINE RUNS BUT VOLTAGE DOES NOT BUILD UP Poor brush contact Check Brush seating on commutator and collector tings free in holders and not worn too short and have good spring tension Refer to the Generator section of Maintenance Residual magnetism lost Magnetize the field Direct short or excessive load on AC circuit VOLTAGE UNSTEADY BUT ENGINE NOT MISFIRING Speed too low Adjust governor to correct speed Refinish commutator or undercut mica if necessary See that brushes seat well on commutator and collector tings are free in holders not worn too short and have good spring tension Tighten Disconnect load Poor commutation or brush contact Loose connections Correct abnormal load con dition causing trouble Fluctuating load GENERATOR OVERHEATING Short in load circuit Correct short circuit Generator over
54. itions Any change in the sensitivity adjustment usually requires a compensating speed spring tension adjustment NOTE Make all final governor adjustments with the arrestor and resonator mounted the carburetor 21 VALVE SERVICE Properly seated valves are essential to good engine performance The cylinder head is removable for valve Servicing Do not use a pry to loosen the cylinder head Rap sharply on the edge with a softefaced hammer A conventional type valve spring lifter may be used when removing the valve spring locks which are of the split type Clean all carbon deposits from the cylinder head piston top valves guides etc If a valve face is burned or warped or the stem worn install a new valve Worn valve stem guides may be replaced from inside the chamber Valve locks are the split tapered type the smaller diameter facing toward the valve head Tappets are replaceable from the valve chamber after the valve assemblies are removed See Figure 18 for valve details NOTE USE A STANDARD AUTOMOTIVE TYPE WRENCH ADJUST THE TAPPETS we VALVE SEAT The valve face angle is 44 valve seat angle is 45 This 1 interference angle results in a sharp seating surface between the valve and the seat This interference angle minimizes face deposits and lengthens valve life Valve seat face should be 1 32 to 3 64 of an inch wide Grind only enough to assure p
55. ld be 0 7 to 1 5 volts If these tests are satisfactory the transistor if defective Replace it WIRING DIAGRAMS The wiring diagrams on the following pages are typical and apply only to standard MCCK series generating plants Wiring diagrams for special models are available on request from the factory send generator model spec and serial numbers with the request 45 C 2 220419 THETA 92 01 SOS Fs 03393 7 02 576 daw SLi 1 Wife E RDOW GOS 5 rifel SESTE 525721 S 8911189 mad ad MAL t apor in E AR Tm adj d mu i i vi 8 8 M429NSO ibe AYNIY Yy 2 0 30457 544 4405 cp SONY dS OV a Sm GEER NOIS s m MC COD Jd zw SOS NIS 4v3H m eestu Thes MLW uoi1si63H Li tw gt 2 529106 10H1NO02 rr OEN ASS Y TENWd MOYANO T HOLIMS abngsaMst TIO ON 35042 201313 NYNO ea TF 5 gt HOLSISSM BOUWHD X P T2 1 idi 4 wd jen y GVO
56. learances CONNECTING RODS Connecting rods should be serviced at the same time pistons or rings are serviced Rods must be removed with the piston Rods are forged steel with replaceable bushings and bearings They are available in standard or 002 0107 020 or 030 undersize For clearances refer to the Repair section On forged steel rods proper clearance is obtained by replacing the pin bushing and the bearings The rod bearings are precision size and require no reaming The piston assembly must be properly aligned before installation Aligning should be done on an accurate gauge by a competent operator Misalignment causes rapid wear of piston pin cylinder and connecting rod Install connecting rods and caps with raised lines witness marks aligned and with the caps facing toward the oil base The rod and cap numbered 2 fits on the crankshaft journal nearer the bearing plate Coat the crankshaft journal bearing surfaces with oil before installing rods Crank engine by hand to see that rods are free If nec essary tap the connecting rod cap screws sharply with a soft faced hammer to set the rod square on the journal CRANKSHAFT Inspect the bearing journals If they ate scored and cannot be smoothed out by dressing down the bearing journals should be refinished to nearest available undersize bearings or a new crankshaft should be installed If a worn main REAR BEARING PLATE ME
57. loaded Reduce load Improper brush rig position Adjust ENGINE OVERHEATING Improper lubrication Change to proper oil Provide ample ventilation at all times Poor ventilation Insufficient water circula tion Clogged restricted watet cooling passages Clean cooling system Check pump and lines Time ignition Retarded ignition timing Generator overloaded Reduce load f POSSIBLE CAUSE REMEDY VOLTAGE DROPS UNDER HEAVY LOAD Engine lacks power Poor compression Faulty carburetion Dirty flame arrester Choke partially closed carburetor venturi Restricted exhaust line ENGINE MISFIRES Carburetor idle jet clogged or improperly adjusted Spark plug gaps too narrow Intake air leak Faulty ignition ENGINE MISFIRES Defective spark plug Faulty ignition Clogged carburetor Clogged fuel screen Defective spark plug cable ENGINE MISFIRES Fouled spark plug Defective or wrong spark plug Leaking valves Broken valve spring Defective improperly adjusted breaker points _ Tighten See remedies under Engine Mistires at Heavy Load Tighten cylinder head bolts spark plugs If still not corrected grind the valves and or piston rings Check fuel system Clean adjust or repair as needed Clean replace Choke plate must be wide open at operating temper ature Carbon in cylinders or in Remove carbon
58. me arrester carburetor and complete carburetor adjustment To clean the fuel strainer remove the fuel sediment bowl and screen Figure 6 and thoroughly wash the screen At the same time remove the carburetor float bowl and clean it Assemble and check for leaks FUEL PUMP AND FILTER BODY FIGURE 6 FUEL STRAINER FUEL PUMP The fuel pump is located on the top of the engine If fuel does not reach the carburetor make the following checks 1 Check fuel level in tank 22 sure shut off valve is open 3 Remove fuel line from pump outlet and the engine over several times Fuel should spurt out of the pump If not remove the pump for repair or replacement Testing If the fuel pump delivers fuel test it with a pressure gauge or manometer Perform these tests before removing the pump from the engine Disconnect the pump outlet line and install the pressure gauge Figure 7 may also cause high pressure PRIMING PRESSURE FIGURE 7 TESTING FUEL PUMP Test the valves and diaphragm by operating the priming lever a few times while watching the pressure It should not drop off rapidly after priming has stopped Run the engine at governed speed on the fuel remaining in the carburetor and measure the fuel pump pressure Pressure should be between 2 and 3psi with the gauge held 16 above the fuel pump low pressure reading indicates wear overhaul or replace the pump If the re
59. me grooved or out of round or the brush surface becomes pitted or rough so that good brush seating cannot be maintained remove the armature and refinish the collector rings in a lathe If the com mutator appears to be rough or scored refinish it at the same time Remove or adequately shield the ball bearing during refinishing COMMUT ATOR Commutator bars wear with usage so that the mica between them must be undercut This should be done as soon as the mica on any patt of the commutator touches the brushes suitable undercutting tool can be made ftom a hack saw blade Avoid injury to the surfaces of the copper bars Leave no burs along the edges of the bars Undercut mica whenever the commutator is refinished See Figure 31 HACK SAW BLADEN TOWARD HANDLE lt MICA PROPERLY UNDERCUT 30 WOODEN GENERATOR TESTING Windings Before making any tests lift all brushes from their holders and disconnect the load circuit wires from the plant If the armature tests defective the practical is to replace it If a field coil tests defective replace the entire coil assembly unless the trouble is in one of the external leads Then it can be repaired as the nature of the trouble requires rmature Ground Lift or remove brushes so that none contact the commutator or collector rings Use a continuity test lamp set Figure 32 Place one test prod on the commutator and the other test prod on a clean
60. mounted in the breaker box aids primary field breakdown when the points open and prolongs the life of the breaker points by reducing the arc across them defective condenser causes a weak spark and rapid breaker point wear Use a standard com mercial condenser tester to determine condenser leakage opens or grounds If no tester is available check for Shorts or defective leads Replace the condenser if in doubt 77 Coil If spark is weak or there is no spark and the breaker points are clean and properly adjusted test the coil for possible defects a general of the coil disconnect and hold the second lead good the spark plug leads ground one 1 4 from the engine Then grank the engine spark indicates the coil is operating Test the as follows Using an ohmmeter check the resistance of the coil windings Normal resistance readings range from 5to2ohms for the primary winding and from 4 000 to 10 0000hms for the secondary winding Extremely low resistance usually indicates a shorted winding and ex tremely high resistance usually indicates an open in the winding caution he 4 volt coils can be tested on a 6volt tester However a 12 volt tester will destroy the coil in a few seconds Spark Plugs MCCK generating plants use aviation type spark plugs equipped to accept suppressed ignition leads Fouled spark plugs indicate they are too cold Consult the plant parts catalog for the factory recommended
61. n the mark on the flywheel aligns with the correct degree mark 25 on the gear cover If marks align as the points break timing is correct they do not loosen the breaker box mounting screws and shift the whole breaker box assembly slightly to the right to retard the timing points breaking too soon or shift it slightly to the left to advance the timing points not breaking soon enough Tighten the breaker box mounting screws securely after making an adjustment see Figure 16 To accurately check timing a timing light may be used when the engine is running FOR MODELS WITH BREAKER BOX PLACE A DROP OF FACING REAR OF ENGINE BREAKER ARH PIVOT ADVANCE SPARR SHAFT EVERY 1200 RETARD SPARK OPERATING HOURS To adjust gap loosen sc turn cam SET BREAKER POINT GAP WIDTH AT 0 020 LOOSEN THE SCREWS TO ADJUST POSITION OF BREAKER BOX FLYWHEEL FIGURE 16 IGNITION TIMING oN e E To accurately check timing when not running the engine connect a continuity test lamp across the ignition breaker points Touch one test prod to the breaker box terminal to which the coi lead is con nected and touch the other test prod to a good ground on the engine Turn the crankshaft against rotation backwards until the points close Then slowly turn the crankshaft with rotation The lamp should go out just as the points break 6 Install the breaker box cover Condenser A 3mfd condenser
62. orreplace as needed Engine overheating High water temp cut out Stops engine Low oil pressure switch Stops engine Low oil pressure DULL METALLIC THUD IF NOT BAD MAY DISAPPEAR AFTER FEW MINUTES OPERATION IF BAD INCREASES WITH LOAD Loose crankshaft bearing Replace unless one of the next two remedies per manently corrects the trouble SHARP METALLIC THUD ENGINE FIRST STARTED Low oil supply Add oil Oil badly diluted Change oil Carbon in cylinders Remove the carbon ESPECIALLY WHEN COLD 7 POSSIBLE CAUSE Spark advanced too far Wrong spark plugs Spark plug burned carboned Valves overheated Fuel stale or low octane Lean fuel mixtute Engine P TAPPING Valve clearance too great Broken valve spring HOLLOW CLICKING SOUND WITH COOL ENGINE REMEDY Set breaker points or time ignition Install correct spark plugs Clean Install new plug if necessaty i Adjust tappet clearance Use fresh fuel Clean fuel system Adjust carburetor jets Check cooling system SOUND Adjust to proper clearance Install new spring UNDER LOAD Loose piston If noise is oniy slight and disappears when engine warms up no immediate attention needed Other wise replace parts neces sary VOLTAGE LOW AT FAR END OF LINE BUT NORMAL NEAR PLANT Too small line wire used for load and distance Install larger or extra wires ot reduce load MOTORS R
63. peed drop not noticeable without instruments will result in an objectionable voltage drop Check engine speed with a tachometer The governor arm is fastened to a shaft which extends from the gear cover and is connected by a ball joint and Be link to the carburetor throttle arm Flyballs behind the cup on the camshaft gear actuate the governor arm If the carburetor has been removed or the governor disassembled it may be necessary to readjust the governor INTERNAL SPRING BRACKET VACUUM CARBURETOR THROTTLE ARM CARBURETOR THROTTLE _ PLATE SPRING GOVERNOR LINKAGE GOVERNOR SPRING BRACKET GOVERNOR SPRING GOVERNOR ARM SHAFT SPRING ADJUSTING STUD FIGURE 17 GOVERNOR AND GOVERNOR ADJUSTMENTS 20 The vacuum booster is separate auxiliary device which supplements the governor The vacuum booster is adjusted to increase governor action which increases engine speed as the generator load is increased This results in nearly constant voltage output The booster is mounted the intake manifold and is actuated by engine vacuum When the plant is operating at half load or less engine vacuum is sufficient to cause the diaphragm to overcome the internal booster spring tension Under these conditions there is no tension on the booster external spring and the booster does not affect governor operation As the plant load increases engine vacuum decreases and the booster internal
64. plifier as follows AC output voltage of Transformer measured at terminals on load sensor amplifier should be 2 to 3 VAC Voltage from ground to the transistor side of Resistor AR should measure 0 6 to 0 7 VDC Voltage across A1CRg should read less than 5 VDC B Voltage across Diode A1CR1 should read 5 to 14 VDC 4 Plant won t stop with load removed a Move the toggle switch to the OFF position to stop the plant If the plant does not stop remove the battery lead and check for a faulty Start Sole noid The contacts may have stuck closed b Remove the load from the load side of the con tactor in the Control O Matic and reconnect battery c Put toggle switch in AUTO position If the plant does not crank place the toggle switch in the RUN position to start the plant Put the switch in AUTO position the plant should stop the plant stops with the load lead removed from the load side of the con tactor it indicates that there was sufficient load on the AC line to keep the Control O Matic energized Recheck the load circuit If the plant cranks with the toggle switch in the AUTO position and the load lead discon nected the Start Run relay or Load Amplifier are malfunctioning Remove the ground lead from battery Remove the Start Run relay Check continuity from Terminal 6 to 7 of Relay 307A62 This circuit should be open Check continuity with 1 1 2volts or less from tube
65. r these points The views shown are modified pictorially Components are shown in their actual positions Normally the top view of each component is shown for terminal location Dotted lines show the edges of the control box and indicate the direction from which it is being viewed i e Top View NOTE For servicing information on optional automatic demand controls for older MCCK plants refer to HA series Automatic Control manual number 907 8 All relays are shown in the de energized position If any control part fails replace the defective part with a part of identical manufacture No attempt should be made to repair such parts as meters fuses switches relays or receptacles Check electrical connections and contacts whenever servicing control equipment Always disconnect the battery to avoid accidentally starting the plant When disassembling controls tag each lead that has to be removed and mark the connection point of the lead on the tag to assure corect connections for assembly CONTROL O MATIC GENERAL DESCRIPTION The Control O Matic standard on newer model MCCK plants is an engine control an automatic demand control and a bilge blower control all combined into one top mounted control box The Control O Matic with its switch in AUTOMATIC position will monitor the AC load circuit to Sense a load on the AC line Close the bilge blower circuit when used Open the bilge blower cir
66. roper seating The valves should not be hand lapped if at all avoidable since the sharp contact may be destroyed This is espe cially important where stellite faced valves and seats are used Remove all grinding dust from engine parts and install each valve in its proper location Check each valve for a tight seat using an air pressure testing tool If such a tool is not available make pencil marks at intervals across the valve face and observe if the marks NOTE SEE VALVE TAPPET CLEARANCES IN TEXT NALVE ADJUSTING RETAINER VALVE DE ea gt J vauve GUIDE se VALVE CLEARANCES INTAKE VALVES 9 011 0 013 EXHAUST VALVES 0 011 0 013 22 FIGURE 18 VALVE DETAILS AND CLEARANCES d tub off uniformly when the valve is rotated part of turn against the seat Lightly oil the valve stems and assemble Adjust the valve clearance The positive type valve rotators serve to prolong valve life and lessen the need for valve service When function ing properly the valve is rotated a fraction of a turn each time it opens While at open position the valve can be rotated freely but in only one direction If rotators are faulty replace TAPPET ADJUSTMENT These plants are equipped with adjustable tappets To make a valve adjustment remove the valve covers Facing the flywheel crank the engine over slowly by hand until the left intake valve opens and closes Continue about 1 4 turn until the
67. sted for two abnormal conditions 1 insufficient water flow and 2 air leaks 1 To measure water flow install a tank of known capacity at the water outlet Run the engine until the thermostat opens and then measure the length of time necessary to fill the tank From this obtain the flow in gallons per minute GPM If water flow is below 3 5 GPM check pump operation and inspect the passages and water lines for clogging 2 Air leaks will cause premature impeller failure test for air leaks insert the cooling system outlet into a tank of water and watch for bubbles while the engine is operating If bubbles appear inspect the cooling system thoroughly to find the source BEARING AND SHAFT ASS BODY RETAINING RING 10 y REAR WEAR PLATE FIGURE 3 RUBBER IMPELLER WATER PUMP REPAIR When making cooling system repairs use Permatex or thread sealing compound on all threaded connections All water lines should be 1 2 inside diameter or larger Long runs of pipe or hose need a larger inside diameter to reduce resistance Thermostats Thermostats are located on the top of each cylinder head These thermostats are connected by tubing to the water cooled manifold Replace a thermostat if damaged by corrosion or other causes Check opening and closing by placing a thermostat and a thermometer in a water bath thermostat should start to open at 145 F and be fully open at 165 F It should close
68. stop pin to protrude to a point 3 4 from the cover mounting surface GOVERNOR CUP With the gear cover removed the governor cup can be taken off after removing the snap ring from the camshaft center pin Catch the flyballs while sliding the cup off Replace any flyballs having a grooved or flat spot the ball spacer if its arms are worn or damaged and the governor cup if the race surface is grooved or rough The governor cup must be a free spinning fit on the cam shaft center pin without too much play When installing the governor cup tilt the engine so the gear is up put the flyballs in place equally spaced and install the cup and snap ring on the camshaft center pin GOVERNOR CUP ROLL PIN gi T Yr 24 vy ROTATE GOVERNOR CUP SO THAT ROLL PIN FITS INTO THE METAL LINED HOLE IN THE CUP A3594 The camshaft center pin extends 3 4 from the camshaft end This provides an in and out travel of 7 32 for the governor cup Figure 20 Hold the cup against the flyballs when measuring If the distance is less remove the center pin and press in a new pin Otherwise grind off the hub of the cup as required The camshaft center pin cannot be pulled outward or removed without damage If the center pin extends out too far the cup will not hold the flyballs properly WHEN GOVERNOR 1 PROPERLY ASSEMBLED THE CAMSHAFT DIMENSION SHOWN dec GEAR ON DRAWING WILL 7 AS INDICATED 7 32 j
69. t an open circuit is indicated IMPORTANT short circuit in the winding might prevent sparking This condition may also be indicated by the short circuit test Replace an open armature with a new rmature Short To test for a short circuit place the armature in a growler and hold a steel strip about 1 2 above the armature laminations Pass the strip back and forth over the laminations Cover as much of the lamination area as possible the strip is magnetically attracted to the armature at any point a short circuit is indicated After testing in one position rotate the armature slightly in the growler nd repeat the test Continue until a complete armature revolution in the growler has been made Replace a short circuited armature with a new one Field Windings Use a test lamp set for all tests except a short circuit The field coils are saturated shunt wound having a series field winding for cranking When testing a field coil assembly disconnect all of its external leads from their terminals Tag and mark each lead to assure proper connections for assembling Testing Field Windings for Grounds To test a coil as sembly for ground disconnect its external leads and touch one test prod to the terminal of one of its leads and the other test prod to the generator frame If the lamp lights the coil assembly being tested is grounded The ground may be in a coil coil connection or coil lead Repair or
70. taps to position it Install the bearing flush with the inside end of the bore If the head of the lock pin is damaged use side cutters or an easy tool to remove then install new pin Apply oil to thrust washer to hold it in place while installing the crankshaft Oil grooves in thrust washers must face the crankshaft Washers must be flat not bent with the two notches fitting over two lock pins to prevent riding on crankshaft New camshaft bearings are a precision type and do not require line reaming or boring Coat the bearing with lubricating oil to reduce friction Place the bearing on the crankcase over the bearing bore with the elongated hole in the proper position and narrow section facing PRECISION TYPE Do not line ream or bore ALIGN HOLE IN BEARING WITH HOLE IN BEARING BORE CAMSHAFT BEARING LOCK PIN T ALIGN BEARING OIL HOLES WITH OIL HOLES IN BEARING BORE ek THRUST WASHER PRECISION TYPE Do not line ream BEARING or bore LOCK PIN CRANKSHAFT BEARING FIGURE 24 CAMSHAFT AND CRANKSHAFT out except bores without oil holes install with bearing groove at the top Be sure to start the bearing straight Press the front bearing in flush with the outside end of the bearing bore Press the rear bearing in flush with the bottom of the counterbore which receives the expansion plug OIL SEALS FIGURE 25 The gear cover must be removed to replace oil seals Drive out the oil seal from insi
71. tery charge current through Lead 51 to Start Solenoid Relay Ke and Terminal 1 to Resistor charge resistor The resistor is divided with the upper Terminal C and the lower Terminal A connected to the contact the Voltage Regulator Ks This supplies the high charge rate for fast battery charging Current flows from the terminal of Relay Ks vee the Reverse Current Diode through the ammeter back to the battery for charging When the battery reaches a preset charge level the coil on Relay Ks is energized opening the contacts and dropping the charge to a low rate Restate is set at the factory for correct two rate charging 40 START DISCONNECT CHOKE HEATER AND BATTERY CHARGE TO BILGE BLOWER 12 B 4 KT 51 0 AUTO Cy Ate o OF ore 0 sare FIGURE 39 a GENERATOR SUPPLYING POWER When the generator AC voltage reaches approximately COP 105 volts on 115 volt units or 210 volts on 240volt units OFF POSITION the coil on the Line Contactor K3 energizes to open the iot BLOWER auxiliary contacts and close the main contacts The 2 MAX generator is now supplying power to the load With the generator supplying power to the load current P AZRI i through the primary winding of Transformer produces roo 9 A current in the secondary and supplies power to the Load ERE Sensor Ampl
72. ust the needle outward about 1 2 turn and again slow down the engine and release the mechanism Continue until the engine accelerates evenly and without a lag after releasing the governor With the carburetor and governor adjusted and the engine tunning with no load Figure 13 allow 1 32 clearance to the stop pin This prevents excessive hunting when a large load is suddenly removed Removal and Disassembly 1 Remove the fuel line governor linkage and electric choke wire 3 Remove the two carburetor mounting nuts remove T carburetor 3 Rakove the silencer adapter and choke from the carburetor 4 Remove the main fuel adjustment needle begin Spec R and the float bowl nut and pull off the bowl Remove the float pin and float 5 Lift out the float valve and unscrew its seat 6 Remove the no load adjusting needle the load ad justing needle Spec A only and spring oe for burrs on throttle shaft and choke shaft at screw attachment points If rough remove burrs before pulling shafts out 16 MAIN FUEL ADJUSTMENT THROTTLE STOP SCREW ye FUEL IDLE ADJUSTMENT FUEL IDLE ADJUSTMENT THIS DISTANCE 1 32 AT NO LOAD MAIN FUEL ADJUSTMENT A FIGURE ADJUSTING GASOLINE CARBURETOR 7 Remove the throttle plate screws and the plate and pull out the throttle shaft 8 Remove the choke plate screws and plate and pull out the choke shaft Remove the main nozzle Sp
73. y K4 LOAD DEMAND ETT BLOWER d SAMP Re em 224 rk A gg TH c2 12 53 FIGURE 34 CLYMAR INC N55 W13787 Oak Lane Menomonee Falls Wisc 53051 41 781 0700 35 TRANSISTOR AND TIME DELAY When Relay K4 energizes contacts 6 7 close the circuit from B to the run terminal on Switch S1 and to Terminal 1 on Relay 2 Bilge Blower Control Current flows through the heater of Relay 2 to the 6 1 4 ampere fuse to ground and back to the battery The heater on the five minute time delay begins its cycle Simultaneously as current flows through the heater on Time Delay A92Ki it also flows through the closed A2K contacts 1 2 through Resistor 2 to the base of the transistor through Re sistor 2 2 and through the fuse to goudd This switches Transistor A2Q1 on 36 TRANSISTOR ON AND TIME DELAY BILGE BLOWER 12V SAMP MAK FIGURE 35 BILGE BLOWER ON When Transistor 201 turns on current flows from the B Terminal through the bilge blower to Terminal BB on Terminal Block through the transistor and through the fuse to ground The bilge blower operates for five minutes to evacuate explosive vapots from the boat bilge At the end of the five minute period Time Delay operates to close contacts 1 3 and open contacts 1 2 Transistor 201 turns off to interrupt the power to the

927-0550 Onan MCCK Marine Genset Major Service manual (04

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