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EH72 Engine - Subaru Industrial Power

1. L tt 7 GRAY T gt WHITE YELLOW YELLOW O OIL PRESSURE A SWITCH 59 RED RED CARBURETOR BLACK BLACK WHITE RED BLACK YELLOW WHITE aij 1 IGNITION IGNITION COIL 2 SPARK OFF PLUG RUN 2 START Key switch SSC Option parts 1 1 5 7 e NN 8 BATTERY CHARGE ELECTRIC COIL GREEN STARTER HOUR METER PET 2000Dx etc With Control box OIL WARNING LAMP L 7 GRAY 3 WHITE LYELLOW YELLOW O OIL PRESSURE A SWITCH LDL RED RED CARBURETOR BLACK BLACK WHITE RED BLACK YELLOW WHITE gi of eL 1 1 x x IGNITION IGNITION i SPARK SPARK Q OFF_ OTO COIL 2 PLUG COIL 1 RUN olo START
2. 77 1 SPECIFICATIONS EH72D Type Air Cooled 4 Stroke V Twin Cylinder Horizontal P T O shaft OHV Gasoline Engine Bore x stroke mm in 2 80 x 65 3 15 x 2 56 2 84 x 65 3 31 x 2 56 cu in Displacement 653 39 9 720 43 9 Compression Ratio 8 3 Continuous Output kW HP r p m 10 8 14 5 3600 11 9 16 0 3600 12 7 17 0 3600 13 4 18 0 3600 Maximum Output kW HP r p m 13 4 18 0 3600 15 3 20 5 3600 16 4 22 0 3600 18 6 25 0 3600 Maximum Torque Nem r p m kgf m r p m ft lb r p m 43 3 2000 4 41 2000 81 90 2000 44 3 2200 4 52 2200 32 69 2200 45 6 2500 4 65 2500 33 63 2500 53 6 2500 5 5 2500 39 78 2500 Direction of Rotation Counterclockwise as viewed P T O shaft side Cooling System Forced Air Cooling Valve Arrangements Overhead Valve OHV Lubrication Full pressure type Trochoid Pump Full pressure type with oil Cooler Lubricant Automotive Engine Oil SAE 20 30 or 10W 30 Class SE or higher Capacity of Lubricant L U S gal Carburetor 1 55 0 41 Down Draft Float Type Down Draft Float Type With Accel Pump Fuel Automotive Unleaded Gasoline Fuel Feed System Diaphragm Pump Pulse type Ignition System Flywheel Magneto Sol
3. o5 Key switch I 8 i I 8 X c NL REGURATOR CHARGE ELECTRIC COIL creen STARTER XTACHO HOUR METER PET 2000DX etc 58 ELECTRIC STARTER When key switch is turned ON lower electric current M flows through coil of magnetic switch and the coil is excited The plunger is pulled and higher current S flows through electric starter When electric starter is operated pinion gear is pushed out by means of centrifugal force of weight located in the spline of armature shaft The pinion gear is engaged with ring gear and flywheel and crankshaft are rotated STARTING MOTOR MAGNETIC SWITCH ELECTRIC STARTER COMPONENT PARTS BATTERY 1 STARTING MOTOR ASS Y 8 BRUSH HOLDER ASS Y 2 ARMATURE ASS Y 9 BRUSH 3 THRUST WASHER KIT 10 BRUSH SET 4 PINION STOPPER SET 11 BRUSH SPRING 5 YOKE ASS Y 12 PINION ASS Y 6 REAR COVER ASS Y 13 GEAR CASE ASS Y 7 STARTER METAL 14 STARTER METAL 59 15 GEAR CASE METAL COVER 16 DUST COVER KIT 17 SHIFT LEVER KIT 18 MAGNETIC SWITCH ASS Y 19 THROUGH BOLT 20 BOLT 21 M TERMINAL COVER SPARK PLUG CAP Check continuity with a circuit tester Spark plug cap has no resistor If there is no continuity replace the spark plug cap SPARK PLUG Sparking performance 8 Over 6 0 mm 0 236 in Electrode gap 6 0 7 to 0 8 mm 0 028 0 031 in Check the sparking performance with an ignition c
4. Cylinder head 1 Carbon deposit in combustion chamber Remove and clean 2 Cylinder head gasket faulty blow by Replace Valve system 1 Improper valve clearance Adjust 2 Valve heat deterioration Replace 3 Valve spring deterioration Replace 4 Improper valve timing 267 Adjust 9 9 ENGINE MISFIRE Phenomenon Possible causes Remedy 1 Improper spark plug gap or damaged electrode Cealn adjust or replace 2 Ignition coil faulty Replace 1 Ignition system 3 Damaged ignition system wirings Replace 4 Poor connection of ignition system wirings Check and connect properly 1 Lean or rich air fuel mixture Disassembly and repair 2 Carburetor clogged Disassembly and repair 2 Fuel system 3 Improper idling adjustment of carburetor Adjust 4 Improper gasoline or water infiltration Replace 1 Valve heat deterioration or improper valve adjustment Adjust or replace 3 Engine core componets 2 Valve spring deterioration Replace 3 Low compression Check adjust or replace 68 10 INSTALLATION Engine life ease of maintenance and inspection frequency of checks and repairs and operating cost all depend on the way in which the engine is installed Review the following instructions carefully for installing the engine 10 1 INSTALLING When mounting the engine carefully examine its position the method of connecting it to a
5. Cooling fan Remove cooling fan from flywheel M6 x 16 bolt amp washer 4 pcs Flywheel Untighten flywheel nut and leave it to M18 Flange nut 1 pc avoid the flywheel fell out Take out flywheel by means of flywheel M5 x 20 bolt amp washer 4 pcs 15A coil M5 x 25 bolt amp washer 4 pcs 30A coil lt lt ak CO M18 NUT M6 BOLT AND WASHER M5 BOLT AND WASHER CHARGE COIL rN FLYWHEEL PULLER 24 Step Parts to remove Remarks and procedures Fasteners Take care the spark plug is hot just after 21 Spark plug stopping engine NGK BPR4EY 1 Disconnect oil hoses with clamps detached 22 Oil cooler EH72 2 Remove oil cooler M6 x 12 Flange bolt 4 pcs 3 Remove bracket unit SPARK PLUG BRACKET UNIT M6 FLANGE BOLT OIL COOLER HOUSE CLAMP OIL HOUSE 2 HOUSE CLAMP OIL HOUSE 1 _ 25 Step Parts to remove Remarks and procedures Fasteners 23 Rocker cover Remove rocker cover along with hook M6 x 28 Flange bolt 8 pcs When removing rocker arm and Bolt pivot M10 65 Flange bolt 8 pcs turn and adjust flywheel at TDC with the Cylinder head and Push roa marking T faced to 1 or 2 on each 24 1 Bolt pivot cylinder head 2 Rocker arm Put the marking of original position onto each push rod rocker arm and valve for reassembly ROCK
6. Q 20 when 20 C Apply black needle of the circuit tester C 200 to 300 0 00 Replace the regulator if the actual resistance value differs from the rated value OIL PRESSURE SWITCH Switching Pressure 1 0 kg cm2 0 3 Inspect the switch action Structure of Oil Pressure Switch Sensor Contact The structure of the oil pressure switch is shown in a right figure When there is no pressure no oil the diaphragm is pressed in by the spring resulting in the contact being ON If the oil pressure rises above the switching pressure the diaphragm is pressed in by the oil pressure which is greater than the spring pressure resulting in the contact being OFF When engine is stopped 0 O continuity When engine is running oo no continuity switch s structure is complicated so if its function cannot be recovered even by cleaning replace the Switch with a new one SOLENOID for Fuel Cut Off of Carburetor Measure the resistance between the cable and body body earth Q 10 when 20 C Check the operation of the solenoid independently Check operation at the cable and the body Applied voltage 8V Faulty operation Replace the solenoid As the solenoid is a constant pull in type when the engine is running If the battery s power is low it may not work when starting the engine because all the available electric
7. CONTROL LEVER FRICTION WASHER BRACKET UNIT speed control Step Parts to remove Remarks and procedures Fasteners Remove pluse pipe at first 13 Fuel pump Remove fuel pump ASSY and detach M6 x 12 Flange bolt 2 pcs bracket M6 x 12 Flange bolt 2 pcs Ignition coil 1 Take out plug cap M6 x 25 bolt amp 2 Remove ignition coil washer 4 pcs 14 3 Cut out stop wire fixing bands 4 Disconnect stop wires from ignition coil IGNITION COIL PLUG TERMINAL M6 BOLT AND SPARK PLUG 2 p ud 6 BOLT AND WASHER ASSY PLUG TERMINAL IGNITION COIL M6 FLANGE BOLT BRACKET fuel pump FUEL PUMP and FUEL FILTER ASSY s HOSE CLAMP HOSE CLAMP PULSE PIPE STEP 13 FUEL FILTER _ 21 Parts to remove Remarks and procedures Fasteners Intake manifold flange nut 4 pcs Disconnect wire connector from regulator baffle M8 FLANGE NUT j GASKET INTAKE MANIFOLD TO KEY SWITCH TO IGNITION COIL WIRE CP TO IGNITION COIL M6 FLANGE BOLT REGULATOR 22 Step Parts to remove Remarks and procedures Fasteners Cylinder baffles 1 2 3 amp 4 M6 x 12 flange bolt 8 pcs CYLINDER BAFFLE 1 M6 FLANGE BOLT 23 CYLINDER BAFFLE 2 Parts to remove Remarks and procedures Fasteners
8. M14 x 12 Drain plug 2 pcs M6 x 14 Flange bolt 4 pcs i M6 x 8 Flange bolt 2 pcs 3 Muffler M8 SUS Flange nut 4pcs M8 x 20 bolt and 4 Muffler bracket washer 2pcs M6 FLANGE BOLT OIL FILLER CAP OIL LEVEL GAUGE MUFFLER MUFFLER BLACKET M8 SUS FLANGE NUT GASKET STEP 1 OIL DRAIN PLUG 9 EIN ON BOTH SIDE 16 CLEANER STEP 5 WING NUT CLEANER ELEMENT CLEANER BASE 6 e p 5 2 9 a E iL gt lt 215 5 3 o oO S 5 s BRI G a O O 5 lt 9 o gt gt o 0 9 5 gt o d 5 gt 9 o G o 2 o lt lt 8 o M6 FLANGE BOLT HOSE CLAMP BREATHER PIPE 9 HOSE CLAMP 17 Step Parts to remove Remarks and procedures Fasteners Blower housing Disconnect fuel pipe and remove blower M6 x 18 Flange bolt 2 pcs Control box housing along with control box 6 x 14 Flange 6 pcs 1 Remove the choke knob M It 4 8 Chock control lever and link 2 Remov
9. N m 70 90 kgf 5 0 6 5 ft lb Pivot bolt 2 Tightening torque 2 lt gt v 16 6 18 6 Nem 170 190 kgf cm 23 VS S gt 3 Adjust valve clearance of 2 cylinder side in the 4 12 3 13 7 ft lb a 1 MARK 1 same manner O 4 Rotate crankshaft several times and be sure to NS MARK I check valve clearance again Adjust valve 2 clearance if necessary Qi 0 5 10 ROCKER COVER PENARE Install rocker cover with new gasket M6 x 28 Flange bolt 8 pcs Tightening torque 6 8 8 8 Nem 70 90 kgf 5 0 6 5 ft lb 95 11 BREATHER PIPE and COVER Attach breather plate breather valve and breather cover to crankcase using proper gaskets Put breather plate in such position as its reed valve opens outside M6 x 14 Flange bolt 2 pcs Tightening torque 2 9 4 9 N m 30 50 2 2 3 6 ft lb NOTE GASKET breather plate M6 FLANGE BOLT BREATHER COVER Never tighten the bolts over the specified torque or gasket is damaged and cut Replace gaskets with new ones if they are torn or damaged 12 SPARK PLUG Install spark plug to each cylinder head Check the carbon and heat damage around electrode and clean or replace with new one as necessary Spark plug NGK BPR4EY Tightening torque New plug Current plug 11 7 14 7 120 150
10. are many bolts fasten opposing bolts Do not fasten bolts in a circular order In other words after tightening one place go to the opposite side and tighten this place next 5 4 2 Pre assembly A CRANKCASE 1 Fix oil pump filter in position 2 Insert ball and spring into the oil relief valve hole and tighten plug to the specified torque Tightening torque 14 7 24 5 N m 150 250 kgf 10 8 18 0 ft Ib 3 Fit governor lever shaft with clip 4 Tighten oil drain plugs on both side of crankcase SNAP PIN 2 GASKET ADAPTER oil cooler GOVERNOR LEVER SHAFT 3 LR PUMP FILTER SPRING relief valve A _ 8 GASKET PLUG oil relief aluminum 32 10 32 FLANGE BOLT Inch B CYLINDER HEAD VALVES and ROCKER ARM NOTE Clean valves and wash cylinder head thoroughly Remove carbon and gum deposits from the valves seats ports and guides Inspect valves valve seats and valve guides Replace valves that are badly burned pitted or warped Valve guides should be replaced when valve stem clearance exceeds specifications Refer to SERVICE DATA for clearance specifications If exceeds draw valve guides out and press new guides in After replacing valves and guides lap valves in place until a uniform ring shows around the face of the valve 1 Attach oil seal only onto intake valve guide 2 Set retainer plate on exhaust valve side 3 Apply oil
11. be rebored when the difference between max and min of diameter reached to 0 1 0 004 1st reboring 80 250 80 269 3 159 3 160 84 250 84 272 3 3169 3 3178 2nd reboring 80 500 80 519 8 169 3 170 84 500 84 522 3 3268 3 3276 0 015 0 0006 PISTON Piston size At skirt in thrust direction 79 968 79 988 8 148 3 149 83 980 84 000 3 3063 3 3071 1st o s 80 218 80 238 3 158 3 159 84 230 84 250 3 3161 3 3169 2nd o s e 80 468 80 488 3 168 3 169 84 480 84 500 3 3260 3 3268 Unit mm in STD PISTON Ring groove side clearance 0 05 0 09 0 0002 0 0035 1 0 03 0 07 4 0 0012 0 0028 0 057 0 175 Oil ring 0 0022 0 0069 Piston pin hole 1 20 989 0 8263 Piston pin outside dia N 20 991 0 8264 Clearance between piston and cylinder at skirt area 0 012 0 051 0 0005 0 0020 0 0 042 0 0 001654 0 2 0 4 0 0079 0 0157 0 2 0 7 Oil ring 0 0079 0 0276 72 Unit mm in CONNECTING ROD Big end inside dia Clearance between big end and crankpin Small end inside dia Clearance between small end and piston pin Big end side clearance 39 000 1 5354 21 010 0 8272 0 010 0 0004 0 1
12. cut valve wiring Check and repair 4 Engine core components malfunction 1 Insufficient tightening of cylinder head bolts Check and retighten 2 Wear of piston piston ring and or cylinder Repair or replace 3 Improper contact of valve and seat Repair 4 Valve seizure Repair 5 Improper valve clearance Adjust 6 Intake manifold gasket leakage Retighten intake manifold bolts or replace gasket 7 Carburetor gasket leakage Retighten carburetor bolts or replace gasket 8 Insufficient tightening of spark plug 64 Retighten 9 3 INSUFFICIENT OUTPUT Phenomenon Possible causes Remedy Low compression Ignition system malfunction Fuel system malfunction 1 Loosen spark plug Retighten or replace gasket 2 Cylinder head gasket leakage Retighten or replace gasket 3 Piston ring s seizure or wear Replace 4 Piston or cylinder wear Repair or replace 5 Incorrect valve and seat contact 6 Valve stem seizure Repair or replace Repair or replace 7 Improper valve clearance 1 Spark plug faulty Adjust Replace 2 Ignition coil faulty 3 Improper air gap between ignition coil and flywheel Replace Adjust 4 Magneto demagnetization 1 Carburetor clogged Replace Disassembly and clean 2 Improper fuel pump operation Disassembly and clean 3 Fuel strainer or fuel hose c
13. following items MAINTENANCE ITEMS REMARKS 1 Clean away dust and chaff from engine Governor linkage is especially sensetive to dust 2 Check fuel leakage from fuel system If any retighten fasteners or replace necessary parts Loose bolts and nuts may come off and result in 3 Inspect for loose hardware and retighten if necessary breakage of other parts 4 Check oil level and add to full level 12 2 PERIODIC MAINTENANCE SCHEDULE Periodic maintenance is vital to safe and efficient operation of engine Check the table below for periodic maintenance intervals It is also necessary to conduct the maintenance and adjustments on the emission related parts listed below to keep the emission control system effective 2 4 6 8 1 Choke system 3 Air cleaner elements Spark plug Fuel hoses clamps and sealing gaskets Carburetor and internal parts Fuel strainer Intake pipe Magneto 5 7 WH nan The following maintenance schedule is based on the normal engine operation Should the engine be operated in extremely dusty condition or in heavier loading condition the maintenance interval must be shortened depending on the contamination of oil clogging of filter elements wear of parts and so on 77 Periodic Maintenance Schedule table Every Every Every Every Every Maintenance Items 8 hours 50 hours 200 hours 500 1000 Daily Weekly Month
14. machine the foundation and the method of supporting the engine When determining its mounting position in particular make sure that gasoline and oil can easily be supplied and checked the spark plug can easily be checked the air cleaner can easily be serviced and that the oil can easily be discharged 10 2 VENTILATION Fresh air is necessary for cooling the engine and burning the fuel In the case the engine is operated under a hood or in a small room temperature rise in the engine room can cause vapor lock oil deterioration increased oil consumption loss of power piston seizure shorter engine life etc making it impossible to operate the engine properly It is necessary therefore to provide a duct or baffle to guide cooling air to the engine to prevent recirculation of he hot air used for engine cooling and temperature rise of the machine Keep the engine room temperature below 50 C even in the hottest period of the year 10 3 EXHAUST GAS DISCHARGE Exhaust gas is noxious When operating the engine indoors be sure to discharge the exhaust gas outdoors If a long exhaust pipe is used in such a case the internal resistance increases causing loss of engine power Thus pipe inside diameter must be increased in proportion to exhaust pipe length Exhaust pipe Less than 3 m long pipe inside diameter 30 mm Less than 5 m long pipe inside diameter 33 mm 10 4 POWER TRANSMISSION TO DRIVEN MACHINES 10 4 1 BELT DRIVE Tak
15. to washer valve spring and valve stem Place cylinder head on flat table and install washer valve spring valve and spring retainer 4 Install rocker arm ROCKER ARM ROCKER ARM COLLET VALVE COLLET VALVE SPRING RETAINER SJ SPRING RETAINER S wave SPRING e 22 SEAL INTAKE VALVE VALVE SPRING Sj BLACK RETAINER PLATE Exhaust valve i spring side onl p y GASKET breather plate BREATHER PLATE GASKET breather plate BREATHER COVER M6 FLANGE BOLT INTAKE VALVE EXHAUST VALVE _ 33 C PISTON RING and CONNECTING ROD 1 PISTON and PISTON RING NOTE Install oil ring first then second ring and top ring Top ring can be fit either way Spread ring only far enough to slip over piston and Install second ring with punched mark beside the gap the top side Into correct groove As for oil ring rails should be placed on Use care not to distort ring and below the expander 7 BARREL SECOND RING RING 7 2 PISTON and CONNECTING ROD PISTONRING SET Apply enough oil to small end of connecting rod 224 and piston pin and fix connecting rod to piston CLIP with piston pin PISTON gt 2 PISTON Use clips on the both side of the piston pin to secure piston pin in position CLIP CONNECTING ROD CONNECTING ROD CAP M8 CONNECTING
16. 0 0039 CRANKSHAFT Crankpin outside dia Journal dia 73 38 956 1 5337 D1 44 984 45 000 1 77102 1 77165 D2 44 986 44 997 1 77110 1 77154 Unit CAMSHAFT Cam height IN and EX Journal outside dia type 35 35 35 37 1 392 1 393 19 967 19 980 0 7861 0 7866 VALVE Valve stem outside dia 5 970 5 985 0 2350 0 2356 5 970 5 985 0 2350 0 2356 Clearance between valve stem dia and valve guide 0 050 0 083 0 00197 0 00327 0 050 0 083 0 00197 0 00327 Valve clearance em 1 74 0 07 0 13 0 003 0 005 Unit mm in TAPPET Stem outside dia 8 954 8 979 0 3525 0 3535 Guide inside dia amp B Cia 9 00 9 015 0 3543 0 3549 0 021 0 061 5R 0 000827 0 002402 Tappet guide clearance VALVE SPRING FREE LENGTH VALVE SEAT ANGLE IN EX Valve cutter angle a Valve contact width b a 90 b 0 7 1 0 0 028 0 039 Compression pressure Fuel consumption Continuous load 3600 rpm Capacity Lubricant Efficacy Consumption X1 Above values are rough standard They will be changed by the engine condition and the environment X2 Oil consumption ha
17. 18 19 20 21 22 23 24 25 26 27 28 29 30 SCREW float pin set MAIN JET GASKET SOLENOID VALVE ASS Y JET slow SPRING adjust screw SCREW throttle adjust NEEDLE idle adjust THROTTLE SHAFT ASS Y FILTER throttle shaft COLLAR THROTTLE VALVE VALVE SET SCREW O RING PLUG ANTI TAMPER 56 31 32 33 34 35 36 37 38 39 40 41 42 43 CLAMP SOLENOID WIRE 45 44 SCREW and WASHER ASS Y SPRING DIAPHRAGM ASS Y COVER ASS Y BODY ASS Y U RING HOLDER SCREW and WASHER ASS Y SCREW body set PIPE connector PIPE connector SPACER SCREW holder set JET 8 ELECTRIC SYSTEM OPERATION AND FUNCTION The ignition system is pointless flywheel magneto with automatic advancing characteristic Being different from the breaker point type ignition system this system is completely free from such troubles as starting up failure owing to dirty burnt or corroded point surface The electronic automatic advancing ensures extremely easy starts and stable high performance at operating speed by advancing the ignition timing to the most suitable point Low Speed Ignition Timing Control Circuit Power Transistor Primary Coil Secondary Coil Spark Automatic 5 Advancing Control Circuit Signal Transistor A ELECTRONIC ADVANCING FLYWHEEL B T D C MAGNETO SYSTEM STEP ADVANCING IGNITION TIMING 500 1000 2000 3000 r p m ENGIN
18. 275 16 3 19 8 ft lb NOTE When depressing connecting rod make sure not to damage another connecting rod Check for free movement of piston and connecting rod by turning crankshaft slowly eji OIL RING ALIGNMENT MARKS 3 TAPPET and CAMSHAFT 1 Apply oil to tappets and install in their original position Push in fully to avoid damage during camshaft installation 2 Lubricate bearing surfaces of camshaft Install camshaft into the crankcase with the timing mark on both crankshaft gear and camshaft alined CAUTION Incorrect alinement will cause malfunction of the engine 4 Adjust side clearance Measure end play of crankshaft and camshaft Adjust end play to 0 using the proper spacer SPACER mm A 0 48 B 2 MAIN BEARING COVER NCAMSHAFT CRANKSHAFT GEAR READING 1 5 e E HEIGHT GAUG j A A 27 CTO e T 3 ut Jn READING 2 E CRANKSHAFT 9 CRANKSHAFT GEAR 7 SPACER 2536 CRANKCASE THICKNESS WITH GASKET TIGHTENED 5 MAIN BEARING COVER 1 Put a oil seal guide onto PTO shaft portion to avoid dama
19. ARM INTAKE AND EXHAUST VALVES ZA S SPARKPLUG 7 X PISTON RING 22 2 PISTON PISTON PIN zs 25 OIL COOLER EH72D ELECTRIC STARTER OIL FILTER CRANKCASE CRANKSHAFT CONNECTING ROD 14 5 DISASSEMBLY AND REASSEMBLY 5 1 PREPARATIONS AND SUGGESTIONS When disassembling the engine memorize the locations of individual parts so that they can be reassembled correctly If you are uncertain of identifying some parts it is suggested that tags be attached to them Have boxes ready to keep disassembled parts by group To prevent losing and misplacing temporarily assemble each group of disassembled parts Carefully handle disassembled parts and clean them with washing oil if necessary Use the correct tools in the correct way When disconnecting electric wirings be sure to hold and disconnect the connector housing 5 2 SPECIAL TOOLS No Special Tool is needed for disassembling and reassembling the engine For pulling off the flywheel universal type puller being popular in the market place as shown in the illustration is needed Use 228 95001 17 Flywheel puller with bolt EH63 64 65 72 DY30 35 41 42 FLYWHEEL PULLER 15 5 3 DISASSEMBLY PROCEDURES Step Parts to remove Remarks and procedures Fasteners Drain engine oil by removing plugs located 1 Engine oil drain ori botH side of oraBkcase
20. E REVOLUTION BASIC THEORY 1 Revolution of the flywheel generates electricity on the primary side of the ignition coil and the base current l flows to the power transistor Current H turns the power transistor ON and the electric current l2 flows 2 At lower engine revolution when the flywheel reached the ignition point the low speed ignition timing control circuit operates to run the base current Is to turn the signal transistor A ON allowing the current H to bypass as current l4 At this moment the power transistor turns OFF and the current l2 is abruptly shut resulting in the high voltage generated in the secondary coil which produces sparks at the spark plug 57 3 At higher engine revolution the advancing control circuit operates at the ignition timing to run the base current Is to turn the signal transistor B ON allowing the current to bypass as current 16 At this moment the power transistor turns OFF and the current l gt is abruptly shut resulting in the high voltage generated in the secondary coil which produces sparks at the spark plug The operating timing of the advancing control circuit advances in accordance with the increase of engine speed resulting in the advancing of ignition timing WIRING DIAGRAM Connect key switch magnetic switch and battery with wirings of proper gauge as shown by the dotted lines in the wiring diagram Without Control box can OIL WARNING LAMP
21. ER ARM PUSH ROD M6 FLANGE BOLT HOOK GUIDE PLATE ROCKER COVER rocker cover M10 FLANGE M6 FLANGE 9 BOLT BOLT PIVOT 1 GUIDE PLATE rocker cover HOOK 10 FLANGE BOLT CYLINDER HEAD 1 GASKET 1 26 Fasteners Parts to remove Remarks and procedures Take out collet valves with spring retainer depressed by hand Take out valve springs Intake amp exhaust valves M6 x 14 Flange bolt 2 pcs Breather cover Breather plate COLLET VALVE COLLET VALVE SPRING RETAINER SPRING RETAINER VALVE SPRING 8 6 22 26 VAENE SERING VALVE BLACK RETAINER PLATE Exhaust valve spring side only GASKET breather plate BREATHER PLATE GASKET breather plate BREATHER COVER M6 FLANGE BOLT INTAKE VALVE EXHAUST VALVE 27 Step Parts to remove Remarks and procedures Fasteners Main bearing cover Take out key from PTO shaft M8 x 45 Flange bolt 10 pcs Wrap PTO shaft with polyvinyl tape not to 26 damage oil seal by key groove edge Tapping with plastic hummer take out main bearing cover GOVERNOR SLEEEVE GOVERNOR GEAR WASHER GOVERNOR gt GEAR SHAFT e S gt M8 FLANGE BOLT GASKET STEP 26 MAIN BEARING COVER 28 Step Parts to remove Remarks and procedur
22. L LEVER HIGH SPEED 7 LOW SPEED 43 M6 SELF LOCK NUT STOP PLATE SPRING WASHER FRICTION WASHER 6 FLANGE _ BOLT BRACKET UNIT X io C speed control SLON Fitting location of governor and governor spring 26 ADJUST GOVERNOR SYSTEM e Governor system is centrifugal flyweight type Governor weight is installed into governor gear driven by crankshaft Governor weight movement is transferred to carburetor throttle lever via governor shaft and lever e Engine speed is maintained at the constant speed by carburetor throttle valve opening and closing operation in accordance with load condition of engine 1 Push speed control lever all the way to the high speed position and fix it by tightening nut 2 Check that governor lever is pulled by governor spring and carburetor throttle valve is fully open 3 Turn governor shaft counterclockwise all the way and tighten lock bolt to secure the lever on the shaft 27 BLOWER HOUSING Attach blower housing to crankcase with control box commonly fixed Connect fuel pipes onto blower housing BLOWER HOUSING Front M6 x 14 Flange bolt 4 pcs Tightening torque 3 9 5 9 N m 40 60 kgf 2 9 4 3 ft Ib BLOWER HOUSING Side M6 x 18 Flange bolt 2 pcs M6 x 14 Flange bolt 2 pcs Tightening torqu
23. ROD BOLT D MAIN BEARING COVER and GOVERNOR GEAR WASHER 1 Insert washer into governor gear shaft GOVERNOR 2 Insert governor gear along with sleeve into GEAR SHAFT P governor gear shaft gt SLEEEVE GOVERNOR GEAR THRUST BEARING MAIN BEARING COVER za 5 4 3 Re assembly 1 CRANKSHAFT Install crankshaft onto crankcase NOTE Apply enough oil to bearing portion of crankcase For smooth fitting of crankshaft assemble oil pump related parts later For easy installation put crankcase on box or wood blocks 2 PISTON and CONNECTING ROD 1 Install piston and connecting rod assembly into cylinder by using a piston ring compressor to hold piston rings NOTE The 1 mark of the connecting rod for 1 cylinder and 2 mark for 2 cylinder should be faced to the PTO side when assembled Apply enough oil to piston rings connecting rod bearings large end and cylinder bore before assembly Set gaps of piston rings as shown in the illustration 2 Temporary fit key and flywheel and turn crankshaft to BTDC bottom dead center Lightly tap the top of piston until large end of the rod meet the pin portion of crankshaft 3 Set connecting rod cap to connecting rod with the alignment marks mated and the clinching portion clinched Tighten bolts to the specified torque M8 Connecting rod bolt 4 pcs Tightening torque 22 0 27 0 Nem 225
24. SEAT AIR 0 PILOT JET MAIN AIR JET EMULSION TUBE TAMPER CAP PILOT OUTLET MIXTURE AIR SLOW AIR BLEED JET ACCELERATION NOZZLE MAIN AIR BLEED JET FUEL CUT VALVE MAIN JET PILOT JET mm FUEL lt AIR 41111 MIXTURE MAIN EMULSION TUBE CHECK VALVE SPRING OUTLET CHECK VALVE FUEL INLET PIPE C FUEL gt MAIN NOZZLE THROTTLE VALVE SLOW PORT IDEL PORT BACUUM PORT SLOW JET MAIN JET m IDEL SCREW v BACUUM CUSHION JET MIXTURE 53 LEAK JET DIAPHRAGM SPRING PUMP DIAPHRAGM mm FUEL lt AIR 1111 MIXTURE FLOAT SYSTEM The float system is consists of a float and a needle valve and maintains a constant fuel level during engine operation The fuel flows from the fuel tank into the float chamber through needle valve When the fuel rises to a specific level the float rises and when its buoyancy and fuel pressure are balanced the needle valve closes to shut off the fuel thereby keeping the fuel at the predetermined level Air vent hole of float chamber is provided around the carburetor air hone and the fuel vapor is sucked into the combustion chamber This closed system has unti dust feature PILOT SYSTEM The pilot system feeds th
25. SERVICE MANUAL Models EH63 64 65 and 72 ENGINES PUB ES2158 Robin America Inc 905 Telser Road Lake Zurich IL 60047 Phone 847 540 7300 Fax 847 438 5012 e mail sales robinamerica com www subarupower com Copyright 2009 Robin America Inc CONTENTS Section Title Page 1 SPECIFICATIONS KOREA Sees 1 2 PERFORMANCE 2 3 FEATURES u ua kr t EXTA ae 7 4 GENERAL DESCRIPTION OF ENGINE COMPONENTS 8 5 DISASSEMBLY AND REASSEMBLY 5 1 PREPARATIONS AND SUGGESTIONS 15 D2 SPEGIAL TOOLS sk aren Euh wae Sur Des 15 5 3 DISASSEMBLY PROCEDURES 16 5 4 REASSEMBLY PROCEDURES 32 5 5 BREAK IN OPERATION eroe Pe ae eee 48 6 LUBRICATION SYSTEM AR e 49 Ta FUEL SYSTEM KR RR UR 52 8 ELECTRIC SYSTEM exiit e rye be ce nc eit EY 57 9 TROUBLESHOOTING 63 10 INSTALLATION crai eina bu re A a Gra EEN 69 11 SERVICE DATA 11 1 STANDARD DIMENSIONS AND SERVICE LIMITS 70 1122 TIGHTENING TORQUE u asa aa OE Re Ch Dee kS EGE 76 12 MAINTENANCE AND STORAGE
26. TORQUE N m kgf 45 4 59 i 1 ni 35 3 57 TORQUE CONTINUOUS RATED HP RECOMMENDED HORSEPOWER RANGE 2000 2400 2800 3200 3600 REVOLUTION 9 r p m EH64D N m kgf m 45 4 59 o 35 3 57 MAXIMUM TORQUE F 15 20 1 kW HP CONTINUOUS RATED HP cr 13 13 4 gt 2 RECOMMENDED HORSEPOWER RANGE 5 6 7 2000 2400 2800 3200 3600 REVOLUTION gt r p m EH65D N m kgf m 45 4 59 35 3 57 E MAXIMUM TORQUE E MUM HORSEPOWER kW HP CONTINUOUS RATED HP o Qa RECOMMENDED X 2000 2400 2800 3200 3600 REVOLUTION r p m EH72D kW HP TV HORSEPOWER N m 55 5 61 Y 2 45 4 59 MAXIMUM TORQUE 6 MAXIMUM HORSEPOWER 15 20 1 CONTINUOUS RATED HP 10 13 4 mx RECOMMENDED HORSEPOWER RANGE 5 6 7 2000 2400 2800 3200 3600 REVOLUTION r p m 6 3 FEATURES Highly rigid structure e High carbon steel forged crank shaft e Light weight tough alminum forged connectiong rod e Ball bearing Special cast i
27. al type combustion chamber for the high combustion efficiency 4 8 VALVE ARRANGEMENT The intake valve is located on flywheel side of the cylinder head The cooling fins and passages design lead cooling air to the exhaust valve area for the optimum cooling Hard alloy valve seats are molded in the cylinder head EXHAUST VALVE INTAKE VALVE 4 9 GOVERNOR SYSTEM The governor is a centrifugal flyweight type which ensures constant operation at the selected speed against load variations The governor gear with governor weights is installed inside of main bearing cover and driven by the crankshaft GOVERNOR GEAR 10 4 10 COOLING SYSTEM The large fins on the flywheel provide sufficient cooling air capacity for cylinder and cylinder head The cylinder baffle helps the cooling air flow efficiently 4 11 LUBRICATION SYSTEM The engine is furnished with full pressure lubrication system The trochoid type oil pump is driven by crankshaft and delivers pressurized engine oil through the full flow type oil filter to the journal and pin portions of crankshaft and camshaft 4 12 IGNITION SYSTEM The ignition system is a transistor controlled magneto ignition system which consists of a flywheel and an ignition coil with a built in transistor installed onto the crankcase IGNITION COIL FLYWHEEL 4 13 CHARGING SYSTEM Multipolar charging coil is p
28. cess The inside of crankcase becomes vacuum condition in accordance with the piston moving upwards to the top dead center The vacuum pressure which is introduced via hose into the pulse chamber of fuel pump pulls the diaphragm and then the inside of pump chamber becomes vacuum condition As the results the suction valve is opened and fuel goes into pump chamber frown suction chamber Pump chamber Suction chamber Pulse chamber 1 9 Suction Pulsing pressure Fuel discharge process The vacuum pressure of crankcase inside is decreased in accordance with the piston moving downwards to the bottom dead center The vacuum pressure of the pulse chamber is also decreased and the diaphragm moved back by means of the return spring force The fuel in the pump chamber is pressed by the diaphragm and delivered to the discharge chamber through the discharge valve Discharge Pump chamber Discharge chamber Pulse chamber f Pulsing pressure 52 7 2 CARBURETOR OPERATION AND FUNCTION EH63 64 65 CHOKE VALVE AIR VENT HOLE NEEDLE VALVE FUEL INLET PIPE FUEL MAIN NOZZLE THROTTLE VALVE BY PASS EH72 CHOKE VALVE AIR VENT FLOAT FLOAT VALVE FLOAT VALVE
29. crankcase Pilots and bosses are machined on the cover for direct mounting of the engine onto such machines as generators and pumps It is easy to inspect inside of the engine after removing the main bearing cover 4 3 CRANKSHAFT The crankshaft is forged carbon steel and the crank pin is induction hardened The output end of the shaft has a crankshaft gear pressed into position Engine oil passages are provided onto the journal and pin portions of crankshaft for lubrication 4 4 CONNECTING ROD AND PISTON The connecting rod is forged aluminum alloy and its large and small ends function as bearings The piston is an aluminum alloy casting and carries two compression rings and one oil ring 4 5 PISTON RINGS The piston rings are made of special cast iron The profile of the top ring is barrel face and the second ring has a tapered face The oil ring is designed for better sealing and less oil consumption in combination with 3 pieces 22 SECOND RING COMBINATION RING 4 6 CAMSHAFT The camshaft is made of special cast iron and camshaft gears are casted together in one piece Each 2 cam robs are provided for intake and exhaust valves correspondingly Both sides of the shaft fit into the plane bearings on the crankcase and main bearing cover 4 7 CYLINDER HEAD The cylinder head is an aluminum die casting which utilizes semi spheric
30. e 2 9 4 9 N m 30 50 kgf 2 2 3 6 ft lb 44 28 FUEL PUMP and FUEL PIPE 1 Install fuel pump bracket onto 2 cylinder baffle V FUEL PUMP BRACKET M6 x 12 Flange bolt 2 pcs Tightening torque 6 8 8 8 N m 70 90 kgf 5 0 6 5 ft lb 2 Install fuel pump onto fuel pump bracket FUEL PUMP EUEE RUNE M6 x 12 Flange bolt 2 pcs Tightening torque 4 5 5 5 Nem 45 56 kgf 3 3 4 1 ft lb 3 Connect fuel pipe between carburetor and fuel pump 29 AIR CLEANER and BREATHER PIPE 1 Connect breather pipe to air cleaner base 2 Fit air cleaner base onto carburetor M6 x 12 Flange bolt 3 pcs Tightening torque 6 8 8 8 Nem 70 90 kgf cm 5 0 6 5 ft lb 3 Connect breather pipe to 1 cylinder head 4 Set air cleaner element along with urethane foam onto base 5 Install air cleaner cover with knob 45 30 OIL PRESSURE SWITCH EH63 64 65 Install oil pressure switch onto crankcase OIL SWITCH ms EH63 64 65 e Install oil pressure switch onto adapter Oil cooler EH72 Tightening torque 5 9 9 8 Nem 60 100 kgf cm 4 3 7 2 ft lb NOTE Not to tighten excessively 31 OIL FILTER Apply oil to O ring and install oil filter by tighte ning about 3 4 turns after attaching cra
31. e fuel to the engine during idling and low speed operation The fuel is fed through the main jet to the pilot jet where it is metered and mixed with the air metered by the pilot air jet The fuel air mixture is fed to the engine through the pilot outlet and the by pass At idling speed the fuel is mainly fed from the pilot outlet MAIN SYSTEM The main system feeds the fuel to the engine at medium and high speed operation The fuel is metered by the main jet and fed to the main nozzle The air metered by the main air jet is mixed with the fuel through the emulsion tube and the mixture is atomized out of the main bore It is mixed again with the air taken through the air cleaner into an optimum fuel air mixture which is supplied to the engine CHOKE The choke is used for easy start when engine is cold When the starter is operated with a choke valve fully closed the negative pressure applied to the main nozzle increases and draws much fuel accordingly thus easily start up the engine ACCELERATOR PUMP SYSTEM EH72 only When the throttle is opened rapidly for acceleration air flow and manifold vacuum change almost instantaneously Because fuel is heavy and lags behind air flow a momentary leanness results The accelerator pump supplies extra fuel for smooth operation during this condition At constant load condition a vacuum passage in the carburetor applies manifold vacuum to the pump diaphragm and the pump diaphragm is held to pul
32. e the choke contol link 6 bolt 1 pc CONTROL BOX LINK PIVOT WAVED BLOWER HOUSING ES CHOKE CONTROL ROD 5 TAPPING sem 24 cd CLAMP SPRING 18 M6 FLANGE BOLT A eo M6 FLANGE BOLT Step Parts to remove Remarks and procedures Fasteners Carburetor At first remove fuel pipe Take out carburetor along with governor rod and rod spring x 80 Flange bolt 2 pcs CARBURETOR GASKET carburetor 19 Step Parts to remove Remarks and procedures Fasteners Governor lever Speed control lever 1 Remove bolt and take out lever Make sure the fitting location of governor springs 2 Disassemble in the following order Governor spring M6 x 12 bolt and washer 3 pcs M6 self lock nut 1 pc 1 18 2 Self lock nut 3 Stop plate 4 Spring washer 5 Friction washer 6 Speed control lever 11 Speed control bracket unit M6 x 12 Flange bolt 2 pcs 12 Starting motor At first remove wiring 8 x 65 Flange bolt 2 pcs M6 BOLT 29 AND WASHER 127 5 N NIA GOVERNOR SPRING SPACER M8 FLANGE STARTING MOTOR ROD GOVERNOR SPRING ROD P STEP 10 rd E SD GOVERNOR 20 6 SELF LOCK NUT STOP PLATE SPRING WASHER FRICTION WASHER SPEED
33. e the following notes into consideration V belts are preferable to flat belts The driving shaft of the engine must be parallel to the driven shaft of the machine The driving pulley of the engine must be in line with the driven pulley of the machine Install the engine pulley as close to the engine as possible If possible span the belt horizontally Disengage the load when starting the engine If no clutch is used use a belt tension pulley or the like 10 4 2 FLEXIBLE COUPLING When using a flexible coupling run out and misalignment between the driven shaft and engine shaft must be minimized Run out and misalignment tolerance are specified by the coupling manufacturer 69 11 SERVICE DATA STD in the following table is the parts dimension from the brand new engine or the spare parts Whereas Limit shows the maximum allowance for the parts to be used on the engine If the measurement exceeds beyond the Limit the part needs to be replaced and or repaired 11 1 STANDARD DIMENSIONS AND SERVICE LIMITS Unit mm in CYLINDER HEAD Flatness 0 05 or less 0 002 or less 0 7 1 0 0 028 0 039 Valve guide inside dia 6 035 6 053 0 2376 0 2383 70 STD Unit mm in Limit CYLINDER Inside dia Roundiness after reboring Oylindricity after reboring 80 000 80 019 3 1496 3 1504 84 000 84 022 3 3071 3 3080 To
34. elief valve after discharging from oil pump Through the oil cooler and cartridge type oil filter the engine oil is provided onto the rotating portions such as journal and pin portion of crankshaft and camshaft The splashed engine oil is provided to the cylinder piston cylinder head valve system The by pass valve is incorporated into the cartridge type oil filter In case that the oil filter element is clogged the engine oil is fed through the by pass valve into the crankcase oil passage EH63 64 65 OIL FILTER CRANKSHAFT Oil relief Valve opening pressure 3 8 kg cm 373KPa Oil puressure switch Camshaft journal Crankshaft journal P T O side Crankshaft journal Flywheel side Crankpin amp Connecting rod large end Splash Cylinder Crankpin amp Connecting rod small end Cam amp Tappet E Rocker arm amp Valve stem 2 Oil pressure switch Normally close type Contact pressure 1 0kg cm 98KPa 49 EH72 OIL PRESSURE SWITCH OIL COOLER CRANKSHAFT OIL PUMP FILTER Oil relief Valve opening pressure 3 8 kg cm 373KPa Oil puressure switch Camshaft journal Oil Crankshaft Crankpin amp Crankshaft cooler journal Connecting rod journal Flywheel side large end P T O side Cylinder D Crankpin amp Connecting rod small end Cam amp Tappet 2 Oil pressure switch Ji Rocker ar
35. es Fasteners Camshaft Mate the markings both on crankshaft gear and camshaft gear and then take out camshaft 27 tappet Put the marking of original position onto each tappet for reassembly Oi 22 CAMSHAFT 29 Step Parts to remove Remarks and procedures Fasteners Connecting rod 1 Remove connecting rod bolts M8 Connecting rod bolt 4 pcs Take out connecting rod cap Piston 2 Push the connecting rod upwards and take out Piston pin clip along with piston og Piston 3 Take out clip and pull out piston pin and then take Piston rings out piston from connecting rod 4 Remove piston rings from piston Put the marking of original position onto each piston ring clip piston pin connecting rod and cap for reassembly 29 Crankshaft 1 Remove key from crankshaft 2 Take out crankshaft from crankcase CLIP PISTON RING SET PISTON PIN PISTON CLIP A STEP 28 5 CLIP CONNECTING ROD CAP 2 OD C PISTON RING SET PISTON M8 CONNECTING ROD BOLT PISTON PIN CLIP CONNECTING ROD CONNECTING ROD CAP M8 CONNECTING ROD BOLT CRANKSHAFT SPACER 30 Step Parts to remove Remarks and procedures Crankcase 1 Disconnect wire connector from oil pressure pump switch and remove switch filter pressure switch 2 Remove oil f
36. fold and install carburetor CARBURETOR 8 80 Flange bolt 2 pcs Tightening Torque 16 6 18 6 170 190 kgf cm 12 3 13 7 ft Ib carburetor 23 CHOKE CONTROL LINK PIVOT Attach chock control link between carburetor WAVED chock lever and chock control lever CHOKE EZ pace Attach governor spring between governor lever CONTROL ROD SCREW d and speed control lever d RETURN SA GA CLAMP SPRING 24 GOVERNOR LEVER Attach governor rod and rod spring between GOVERNOR S governor lever and carburetor throttle lever and LEVER 25 insert the governor lever to governor lever f shaft Tighten locking bolt temporarily GOVERNOR SHAFT I 42 25 SPEED CONTROL LEVER 1 Install speed control bracket onto intake manifold 2 Attach return spring spacer friction washer wing nut etc to speed control lever as shown in the ilustration 3 Connect governor spring to governor lever and speed control lever 4 Fit chock control link between carburetor chock lever and chock control lever CARBURETOR fe T Eg GOVERNOR GEAR GOVERNOR LEVER GOVERNOR ROD FULL OPEN FULL CLOSE NOLO ADJUSTING screw SPEED CONTRO
37. ging the main bearing cover oil seal 2 Place gasket onto the mating surface of crankcase 3 Lubricate oil seal lip portion and bearing surfaces and install main bearing cover Tighten bolts evenly to the specified torque M8 x 45 Flange bolt 10 pcs Tightening torque 22 5 27 5 Nem 230 280 kgf 16 5 20 2 ft Ib NOTE Before installing main bearing cover be sure to check the installation of governor lever shaft and oil pump filter in the crankcase in position Tap cover with a soft hammer until tacthing the crankcase mating surface engaging with governor gear and camshaft gear properly Rotate crankshaft slowly to check for smooth operation and side clearance 6 OIL PUMP and COVER 27275787 Sip NRE BYES 1 Apply oil to inner and outer rotors of oil pump e s 5 77 and attach them in position T 4 MARKING 2 Set O ring in position 3 Install oil pump cover with the allow marking upwards M6 x 18 Flange bolt 4 pcs Tightening torque 6 8 8 8 Nem 70 90 kgf cm 5 1 6 5 ft lb 7 CYLINDER HEAD gt QUA 2 OUTER ROTOR 1 Set dowel pins in the holes on the cylinder head surface NOTE 2 Attach head gaskets in position onto 1 and 2 cylinder head surfaces 3 Install 1 and 2 cylinder heads Tighten bolts evenly in steps to the specified torque M10 x 65 Flange bolt 4 pcs Tighten
38. hecker D Spark plug cap To spark plug or Engine body earth Start cranking in the same way as starting the engine and inspect whether spark is greater than the rated value In case of no spark or sparking performance a is less than 6 mm 0 236 in Clean the spark plug Adjust the electrode gap Gasket Replace the spark plug Check the ignition coil next page Electrode gap b 0 7 to 0 8 mm 60 Spark plug Ignition checker Ignition Engine body cable IGNITION COIL Adjust the air gap between the ignition coil and flywheel using a thickness gauge and tighten bolts Ignition coil air gap 0 3 0 5 mm 0 012 0 020 in Measure the resistance between the wires and core Resistance High tension cable Secondary 1 Stop wire Primary 2 8 16 KQ Replace the ignition coil if the actual resistance value greatly 0 50 differs from the rated value Q 20 when 20 C CHARGE COIL Measure the resistance between the wires and Q Replace the charge coil if the actual resistance value differs from the rated value Q 20 when 20 C pc THICKNESS GAUGE COIL D Wy ANC L ON 2 2 3 m lt E 22 lt ON 2 EX 1 REGULATOR Measure the resistance between the wires Rated resistance value
39. ic starter operates but engine does not start 1 No fuel Refill 2 Poor connection or discontinuity of ignition system wirings Check repair or replace 3 Electric starter faulty Repair or replace A 63 9 2 STARTING DIFFICULTIES Phenomenon Possible causes Remedy Low engine speed at starting 1 Battery discharged Charge battery 2 Poor connection between battery and starter motor Clean or repair 3 Poor connection between battery and ground Clean or repair 4 Electric starter faulty Repair or replace 5 Improper engine oil Replace with recommended engine oil Ignition system malfunction Spark plug Improper spark plug gap No insulation Carbon deposits Adjust Replace Clean Ignition coil No insulation or discontinuity Poor connection or discontinuity of ignition code Replace Repair or replace Improper air gap between ignition coil and flywheel Adjust 3 Fuel system malfunction 1 No fuel in fuel tank Refill 2 Fuel pump clogged Clean 3 Fuel hose clogged or pinched Clean or replace 4 Air mixing into fuel lines Check and adjust connecting portion 5 Improper gasoline or water infiltration Replace 6 Carburetor Overflow Clogged or damaged Improper operation of throttle valve Adjust Disassembly and clean Check and adjust 7 Poor connection of fuel
40. id State Spark Plug NGK BP6ES Charging Capacity Starting System 12 15 STD 12 30 Option Electric Starter Governor System Centrifugal Flyweight Type Air Cleaner Double Element Type Dry Weight kg Ib 44 97 0 Overall Length X Width X Height mm in 317 x 477 x 475 12 5 x 18 8 x 18 7 Specifications are subject to change without notice 2 PERFORMANCE 2 1 MAXIMUM OUTPUT The maximum output is the output of an engine with its throttle valve fully opened under the condition that all the moving parts are properly worn in after the initial break in period A new engine may not produce full maximum output while its moving parts are still not broken in NOTE Power curves shown in the following charts are made in conformity to SAE internal combustion engine standard test code J1349 2 2 CONTINUOUS RATED OUTPUT The continuous rated output is the output of an engine at optimum governed speed which is most favorable from the view point of engine s life and fuel consumption When the engine is installed on a certain equipment it is recommended that the continuous output required from the engine be kept below this continuous rated output 2 3 MAXIMUM TORQUE The maximum torque is the torque at the output shaft when the engine is producing maximum output at certain revolution 2 4 PERFORMANCE CURVES EH63D HORSEPOWER MAXIMUM
41. il gauge inserted Use SE API classification or higher grade engine oil OIL GAUGE OIL GAUGE UPPER LEVEL UPPER LEVEL UPPER LEVEL LOWER LEVEL LOWER LEVEL LOWER LEVEL kL 5 5 BREAK IN OPERATION An engine that has been completely overhauled by being fitted with a new piston rings valves and connecting rod should be thoroughly RUN IN before being put back into service Good bearing surfaces and running clearances between the various parts can only be established by operating the engine under reduced speed and loads for a short period of time While the engine is being tested check for oil leaks Make final carburetor adjustment and regulate the engine operating speed Engine speed rpm 2500 No Load 3000 3600 5 4kW 7 3HP 5 9kW 7 3HP 6 3kW 8 5HP 6 7kW 9 0HP 3600 10 8kW 14 5HP 11 9kW 14 5HP 12 7kW 17 0HP 13 4kW 18 0HP 3600 48 6 LUBRICATION SYSTEM OPERATION AND FUNCTION Full lubrication system is adopted in combination with large size torchoid oil pump and cartridge type oil filter The large size trochoid type oil pump is driven directly by crankshaft and delivers pressurized engine oil to the journal and pin portions of crankshaft camshaft etc The engine oil in the oil pan is fed through the oil pump filter into oil pump and the engine oil pressure is adjusted by the r
42. ilter and adapter pump filetr relief spring amp ball 3 Remove oil pump filter Governor lever shaft 30 4 Remove oil relief plug and take out spring and ball Make sure spring is jumped out 5 Take out snap pin and pull out governor shaft Make sure not to loose washer 6 Remove oil pump cover outer rotor inner rotor and o ring Fasteners M6 x 28 Flange bolt 3 pcs 10 32 x 11 1 pc M14 x 12 M6 x 14 Flange bolt 4 pcs SNAP PIN INNER ROTOR GOVERNOR LEVER SHAFT 10 32 FLANGE STEEL BALL 2 SPRING relief OIL FILTER _ GASKET aluminum PLUG oil relief amp OIL PRESSURE SWITCH EH65 OIL FILTER ed 5 4 REASSEMBLY PROCEDURES 5 4 1 PRECAUTIONS FOR REASSEMBLY 1 Clean parts thoroughly before reassembly Pay most attention to cleanliness of piston cylinder crankshaft connecting rod and bearings 2 Scrape off all carbon deposits from cylinder head piston top and piston ring grooves 3 Check lip of oil seals Replace oil seal if the lip is damaged Apply oil to the lip before reassembly 4 Replace all the gaskets with new ones 5 Replace keys pins bolts nuts etc if necessary 6 Torque bolts and nuts to specification referring to the TORQUE SPECIFICATIONS 7 Apply oil to rotating and sliding portions 8 Check and adjust clearances and end plays where specified in this manual 9 When there
43. ing torque 41 0 49 0 N m 400 500 kgf cm 30 2 36 1 ft Ib 37 Be sure to check dowel pin and replace with new one if damaged Tighten the cylinder head bolts in diagonal order Tightning Torque Cylinder head bolts 1st step Final step 25 45 Nem M10 x 65 mm boy bolt 255 357 kgf cm 459 kgf cm Us pee 18 4 ft Ib 25 8 ft lb 33 2 ft lb 8 PUSH RODS Rotate crankshaft to the position in the no lifted condition of tappet Be sure to loose the rocker arm adjust screw 1 Insert push rods into the concave portion of tappet and set the other end to the concave portion of rocker arm adjust screw with valve spring depressed 2 Temporally tighten adjust screw 9 VALVE CLEARANCE ADJUSTMENT NOTE Temporally fit the flywheel in position for easy operation 1 Rotate crankshaft clockwise to the TDC top dead center of compression stroke by matching the mark T of flywheel with the mark 1 of 1 cylinder head 2 Loosen lock nut on rocker arm and turn adjusting screw to adjust the clearance between rocker arm and valve stem end and then tighten lock nut to the specified torque THICKNESS GAUGE Valve Clearance Cold condition 0 07 0 13 mm 0 003 0 005 in Lock nut Tightening torque 6 8 8 8
44. ity is occupied by the starting motor Charge or replace the battery Reference Solenoid pull in force 0 3 kg cm2 62 9 TROUBLESHOOTING The following three conditions must be fulfilled for satisfactory engine start 1 The cylinder filled with a proper fuel air mixture 2 Good compression in the cylinder 3 Good spark properly timed to ignite the mixture The engine cannot be started unless these three conditions are met There are also other factors which make engine start difficult e g a heavy load on the engine when it is about to start at low speed and a high back pressure due to a long exhaust pipe The most common causes of engine troubles are given below 9 1 NO ENGINE OPERATION Phenomenon Possible causes Remedy 1 Electric starter does not operate 1 Poor connection of key switch wiring Check repair or replace 2 Wiring discontinuity between key switch and starter motor Replace 3 Wiring discontinuity between battery and starter motor Replace 4 Improper battery low capacity or dicharged battery Charge or replace battery 5 Poor connection of battery terminal Check clean or replace 6 Starter magnetic switch faulty Check clean repair or replace 7 Starter motor faulty Repair or replace 8 Crankshaft seizure Check repair or replace 9 Seizure between piston and cylinder Check repair or replace 2 Electr
45. kgf 8 6 10 8 ft lb 22 1 26 9 225 275 kgf cm 16 3 19 8 ft lb 13 CHARGE COIL Install charge coil with the wiring located at 2 o clock position M5 x 20 bolt amp washer 4 pcs 15A coil M5 x 25 bolt amp washer 4 pcs 30A coil Tightening torque 2 9 3 9 N m 30 40 kgf cm 2 2 2 9 ft lb 14 STARTER MOTOR Install starter motor M8 x 65 Flange bolt 2 pcs Tightening torque 16 6 18 6 Nem 170 190 kgf 12 3 13 7 ft lb 15 CYLINDER BAFFLE Attach cylinder baffle 1 2 and 3 CHARGE COIL DS f PULLING M8 FLANGE S 1 2 pcs Saly ELECTRIC STARTER Attach cylinder baffle 4 with the charge coil harness retracted in the dent portion M6 x 12 Flange bolt 39 16 INTAKE MANIFOLD GASKET muffler 1 Set gasket stainless steel onto both 1 and 2 8 FLANGE NUT cylinder head 2 Install intake manifold flange nut 4 pcs Tightening torque 16 6 18 6 N m 170 190 kgf 12 3 13 7 ft lb 17 OIL COOLER EH72 only 1 Attach bracket 2 Assemble oil cooler onto bracket M6 x 12 Flange bolt 4 pcs OIL COOLER Tightening torque 6 8 8 8 N m 70 90 kgf cm 5 0 6 5 ft Ib 18 REGULATOR Install regurator onto cylinder baffle 1 Install regulator onto cylinder baffle 1 with the ter
46. l position When the throttle is opened rapidly for acceleration the manifold vacuum is dropped the pump diaphragm moves by the diaphragm spring the fuel in the pump chamber push out by the pump diaphragm and the fuel gush out from the accelerator pump nozzle FUEL CUT VALVE Fuel cut valve operated with starter key switch is equipped with main system of carburetor for preventing engine running on and after burning When the key switch is on the valve is activated and the plunger is pulled in to open the main jet When the key switch is off the power source to the valve is off The plunger is pushed out by the return spring and stop the fuel flow of main jet 54 COMPORNENT PARTS EH63 64 65 1 BODY lower 11 MAIN JET 2 GASKET body upper 12 SOLENOID VALVE ASS Y 3 BODY upper 13 JET slow 4 LEVER ASSY choke 14 NEEDLE idle adjust 5 SPRING choke 15 THROTTLE SHAFT ASS Y 6 SHAFT ASSY choke 16 THROTTLE VALVE 7 CHOKE VALVE 17 EXPANSION PLUG 8 VALVE float 18 PLUG 9 FLOAT ASSY 19 O RING 10 FLOAT PIN 20 PLUG anti tamper 55 EH72 O Q WD 2 4 ar o BODY lower GASKET air horn BODY upper LEVER ASS Y choke RING choke lever SPRING choke COLLAR choke FILTER choke shaft SHAFT ASS Y choke CHOKE VALVE SCREW valve set SCREW air horn set VALVE float FLOAT ASS Y FLOAT PIN 16 17
47. logged Clean or replace 4 Air mixing into fuel lines Check and adjust connecting portion 5 Improper gasoline or water infiltration Replace Low intake air volume 1 Air cleaner clogged Clean or replace 2 Throttle valve faulty 9 4 OVERHEAT Phenomenon Possible causes Repair or replace Overheating 1 Cooling air flow obstructed at inlet or cylinder baffle portion Clean 2 Improper engine oil Replace 3 Lean air fuel mixture Check and adjust carburetor 4 Excessive back pressure of exhaust system Check clean or replace 5 Over load 65 Change to rated load 9 5 ROUGH IDLING Phenomenon Possible causes Remedy 1 Carburetor 1 Low idling speed Adjust 2 Carburetor slow system passage clogged Check and clean 2 Intake system 1 Air mixing from connecting portion of air intake system Check tighten or replace gasket 3 Cylinder head 1 Cylinder head gasket faulty blow by Replace 4 Valve system 1 Improper valve clearance Adjust 2 Leakage from valve seat Adjust valve seat contact 3 Excessive clearance between valve stem and guide Replace 5 Ignition system 1 Weak ignition spark Check and replace spark plug 9 6 HIGH ENGINE OIL CONSUMPTION Phenomenon Possible causes Remedy 1 Loosen drain plug Tighten 2 Drain plug gaske
48. ly hours Clean engine and check bolts and nuts Daily Check and refill engine oil Refill daily up to upper level Change engine oil Note 1 Initial 20 hours Every 100 hours Replace engine oil filter Note 1 Initial 20 hours Every 100 hours Check battery electrolyte fluid level Clean spark plug Clean air cleaner Clean spark arrester Optional part Replace air cleaner element Clean fuel strainer Clean and adjust spark plug and electrodes Replace spark plug Remove carbon from cylinder head Clean and adjust carburetor EN Clean engine base oil pan Check and adjust valve clearance Replace fuel lines Overhaul engine Note 2 1 Initial oil change and oil filter replacement should be performed after 20 hours of operation Thereafter change oil every hundred 100 hours and replace oil filter 200 hours Before changing oil check for a suitable way to dispose of old oil Do not pour it down into sewage drains onto garden soil or into open streams Your local zoning or environmental regulations will give you more detailed instructions on proper disposal Note 2 As to the procedures please refer to the Service Manual or consult your nearest service dealer Note 3 More frequent oil changing oil filter replacement and air cleaner service on replacement may be necessary depending on operating co
49. m amp Normally close type Contact pressure 1 0kg cm2 98KPa 50 ENGINE OIL Using engine oil of the correct grade and viscosity greatly lengthens engine life and improves performance Too much or too little oil can also result in serious problems including engine seizure e CLASSIFICATION BY OIL GRADE API American Petroleum Institute Classification SA SB SC SD SE SF SG SH SJ jp Grades suited for Robin Engine SE or higher SG SH or SJ in recomended e CLASSIFICATION BY OIL VISCOSITY SAE Society of Automotive Engineers ow 130 EET ON Ambient ar 10 0 10 20 30 40 C temperature 14 32 50 68 86 104 F Be sure to use automobile engine oil of the viscosity shown in the table above depending on environmental air temperature rg When the air temperature falls below 20 C or rises above 40 C be sure to choose engine oil of appropriate viscosity and grade according to the prevailing conditions Care must be taken when using multi grade engine oil because the oil consumption rate tends to increase when the air temperature is high e ADDING AND CHANGING ENGINE OIL O Engine oil inspection and filing up Every time you use the engine add engine oil up to the designated maximum level O Engine oil change First time After 20 hours use Thereafter Every 100 hours use 51 7 FUEL SYSTEM 7 1 FUEL PUMP Fuel suction pro
50. minal of earth wire white commonly fixed on the right hand side Connect charge coil wire connector to regulator Connect wire green to magnetic switch M6 x 18 Flange bolt 2 pcs CYLINDER BAFFLE 1 BOLT REGULATOR 19 FLYWHEEL 1 Put woodruff key in the keyway of crankshaft 2 Wipe off oil and grease thoroughly from tapered portion of crankshaft and flywheel center hole 3 Install flywheel to crankshaft and tighten flywheel nut with washer M18 flange nut 1 pc Tightening torque 100 120 Nem 1020 1220 kgf 73 8 88 5 ft Ib 40 20 IGNITION COIL and WIRE CP Temporally fit ignition coil to crankcase THICKNESS GAUGE IGNITION COIL Adjust air gap between ignition coil and flywheel using a thickness gauge and tighten bolts Ignition coil air gap 0 3 0 5 mm 0 012 0 020 in M6 x 30 bolt amp washer 4 pcs Tightening torque 6 8 8 8 N m 70 90 kgf cm 5 1 6 5 ft lb Connect wiring from key switch to the primary ZA KEY SWITCH terminal of ignition coil TO IGNITION COIL 1 WIRE CP TO IGNITION COIL 2 21 COOLING FAN Attach cooling fan onto flywheel M6 x 16 bolt amp washer 4 pcs BOLT and SHER 4 pcs Tightening torque 6 8 8 8 N m 70 90 kgf cm 5 1 6 5 ft lb 2 1 22 CARBURETOR M8 FLANGEBOLT Set gasket onto intake mani
51. nditions This would include dusty environment high ambient temperature heavy engine loading 78 12 3 SPARK ARRESTER OPTIONAL In a dry or wooded area it is recommendable to use the product with a spark arrester Some areas require the use of a spark arrester Please check your local laws and regulations before operating your product The spark arrester must be cleaned regularly to keep it functioning as designed A clogged spark arrester Prevents the flow of exhaust gas Reduces engine output Increases fuel consumption Makes starting difficult If the engine has been running the muffler and the spark arrester will be very hot Allow the muffler to cool before cleaning the spark arrester How to remove the spark arrester MUFFLER 1 Remove the flange bolts from the muffler cover and remove the muffler cover 2 Remove the special screw from the spark arrester and remove the spark arrester from the muffler Clean the spark arrester screen SPARK ARESSTER SCREEN Use a brush to remove carbon deposits from the spark arrester screen Be careful to avoid damaging the screen The spark arrester must be free of breaks and holes Replace the spark arrester if it is damaged Install the spark arrester and muffler protector in the reverse order of disassembly _ 79 12 4 ENGINE STORAGE 1 Change the engine oil and perform the daily maintenance items above mentioned 2 Drain fuel from carbureto
52. nkcase surface Tightening torque 9 9 14 7 N m 100 150 kgf cm 16 3 19 8 ft lb EH72 NOTE Start engine after assembling and check for no oil leakage from oil filter 3 4 TURNS OIL FILTER O RING 46 32 FUEL PUMP PLUSE PIPE Connect fuel pipe between fuel pump and crankcase nipple 33 MUFFLER 1 Install Muffler bracket onto Cylinder head x 20 bolt amp washer 2 pcs M6 FLANGE BOLT Tightening torque 16 6 18 6 170 190 kgf cm 12 3 13 7 ft Ib 2 Install Muffler onto Muffler bracket and Cylinder M6 FLANGE head BOLT M8 SUS flange nut 4 pcs Tightening torque 16 6 18 6 N m 170 190 kgf cm MUFFLER 7 12 3 13 7 ft lb MUFFLER BLACKET 3 Install Muffler cover onto Muffler 6 Flange bolt 6 pcs Tightening torque 6 8 8 8 Nem 70 90 kgf cm 5 0 6 5 ft lb 34 FINAL CHECK Be sure to check loosen bolts and nuts and also electric wiring connections 47 35 ENGINE OIL Refill engine oil and start the engine Engine oil will be lubricated oil passages and oil filter Check the engine oil level and refill again to the upper level of oil level gauge Standard Option OIL GAUGE Oil Capacity 1 55 liter 0 41 U S gal NOTE Check the oil level with the o
53. r float chamber 3 To prevent rust in the cylinder bore apply oil through the spark plug hole and turn the crankshaft several turns by hand Reinstall the plug 4 Turn the crankshaft by hand and leave it where the resistance is the heaviest 5 Clean outside of the engine with oiled cloth 6 Put a plastic cover or the like over the engine and store the engine in dry place 80 PRINTED IN THE USA
54. ron cylinder liner Long lasting structure e Forced pressure lubrication of crankshaft by directly connected trochoid pump e Standard equipped oil cooler ensures a good lubrication environment e Ball bearing installed in the throttle bearing of the carbureter Reliability e Unusually high dust proofing by a double compartment air cleaner and inner vent type carbureter e Carbureter equipped with acceleration pump and receives excellent throttle response eA fine distribution suction pipe and effective combustion chamber shape provide greater cubustion stability and reduced gas emissions Compact e Center height 133 3mm and 25HP e 90 V2 cylinder built in crankcase 4 GENERAL DESCRIPTION OF ENGINE COMPONENTS ROBIN EH63D 64D 65D 72D engine is air cooled 4 stroke twin cylinder OHV arrangement gasoline engine The twin cylinder is located in the angle of 90 degree 1 cylinder is in the RH side and 2 cylinder in LH side as viewed from flywheel cooling fan side 4 1 CYLINDER AND CRANKCASE The twin cylinder and crankcase is single piece aluminum die casting The cylinder liner made of special cast iron is molded into the aluminum casting The crankcase has a mounting surface on the output shaft side where the main bearing cover is attached 4 4 2 MAIN BEARING COVER The main bearing cover is an aluminum die casting which is mounted on the output shaft side of the
55. rovided inside of flywheel Charging capacity is 12V 15A or 12V 30A 12V 15A 12V 30A CABLE EXTENDED REGULATOR REGULATOR CHARGE COIL 7 11 4 14 CARBURETOR The engine is equipped with a down draft carburetor that has a float controlled fuel system and a fixed main jet The carburetors are calibrated carefully for the sure FUEL CUT starting low fuel consumption and sufficient output ZZ SOLENOID VALVE Fuel cut solenoid valve is provided to prevent engine 962 running on when the key switch is turned to off Accelerator pump is provided for obtaining quick and good throttle response EH72D ACCELERATOR PUMP 4 15 AIR CLEANER CLEANER COVER The air cleaner is a heavy duty type with a dual element system primary side is urethane foam half wet and secondary side is dry type WING NUT E NN MN WY 4 Z AX CZ ELEMENT 4 16 FUEL PUMP The engine is equipped with a diaphragm type fuel pump which is operated by the crankcase inside vacuum pressure FUEL PUMP 12 4 17 SECTIONAL VIEW OF ENGINE CARBURETOR C N im kn 4 TA OE FA 4 id WE d J Ho P T O SHAFT 21 FLYWHEEL OIL PUMP FILTER 13 AIR CLEANER CAMSHAFT GOVERNOR LEVER PUSH ROD x ROCKER
56. s been measured under following condition Good break in operation has been finished Oil 10W 30 Grade SE Load Continuous load 3600 rpm 75 11 2 TIGHTENING TORQUE N m Tightening Torque kgf cm ft lb Breather cover 2 9 4 9 30 50 2 2 3 6 Carburetor bolts 16 6 18 6 170 190 12 3 13 7 Charge coil 2 9 3 9 30 40 22 29 Connecting rod cap bolts 22 27 225 275 16 3 19 8 Cylinder head bolts 41 49 400 500 30 2 36 1 Flywheel nut 100 120 1020 1220 73 8 88 5 Ignition coil 6 8 8 8 70 90 5 0 6 5 Intake manifold bolts Main bearing cover bolts 16 6 18 6 22 5 27 5 170 190 230 280 12 3 13 7 16 5 20 2 Oil filter 9 9 14 7 100 150 7 3 10 8 Oil pressure switch 5 9 9 8 60 100 4 3 7 2 Cil relief plug 14 7 24 5 150 250 10 8 18 0 Lock nut Rocker arm 6 8 8 8 70 90 5 0 6 5 Pivot bolt 16 6 18 6 170 190 12 3 13 7 Rocker cover 6 8 8 8 70 90 5 0 6 5 New one 11 7 14 7 120 150 8 6 10 8 Spark plug Current one Starter motor bolts 22 1 26 9 16 6 18 6 76 225 275 170 190 16 3 19 8 12 3 13 7 12 MAINTENANCE AND STORAGE 12 1 DAILY MAINTENANCE Every day before operating engine check the
57. t damaged Replace 3 Incorrect oil filter fitting Repair 1 Oil leakage 4 Loosen main bearing cover bolts Tighten 5 Main bearing cover gasket damaged Replace 6 Crankshaft oil seal damaged Replace 2 Oil dilution 1 Piston oil ring faulty Replace 2 Piston rings seizure wear or poor contact Replace 3 Excessive wear of piston and cylinder Replace 4 Excessive wear of valve stem Replace 5 High oil level Adjust oil level 6 Breather faulty Repair or replace 66 9 7 HIGH FUEL CONSUMPTION Phenomenon 1 Fuel system Possible causes 1 Over size main jet Replace 2 Needle valve faulty and or high fuel level in float chamber Adjust or replace 3 Chock valve does not open fully Repair or replace 2 Engine core components 1 Low compression Check or repair 2 Over cooling 9 8 DETONATION Phenomenon Possible causes Check and adjust load and or engine speed Remedy Ignition system malfunction 1 Poor connection of ignition system wirings Check and connect properly 2 Improper or damaged spark plug Clean or replace Fuel system malfunction 1 Lean or rich air fuel mixture Clean adjust or replace 2 Carburetor damaged Disassembly and clean 3 Fuel lines clogged or damaged Clean or replace 4 Air mixing from connecting portion of air intake system Connect properly or replace gasket

EH72 Engine - Subaru Industrial Power

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