Robin America eh72 Manual de Serviço

SERVICEMANUALEH72ENGINESModelPUB-ES1545Rev. 09/03

4-4 CONNECTING ROD AND PISTONThe connecting rod is forged aluminum alloy, and itslarge and small ends function as bearings.The piston is an aluminum a

– 7 –4-7 CYLINDER HEADThe cylinder head is an aluminum die-casting whichutilizes semi-spherical type combustion chamber forthe high combustion efficie

– 8 –4-10 COOLING SYSTEMThe large fins on the flywheel provide sufficientcooling air capacity for cylinder and cylinder head.The cylinder baffle helps

– 9 –4-14 CARBURETORThe engine is equipped with a down draft carburetorthat has a float controlled fuel system and a fixedmain jet.The carburetors are

– 10 –4-17 SECTIONAL VIEW OF ENGINECARBURETOROIL PUMPIGNITION COILFLYWHEELINTAKE MANIFOLDOIL PUMP FILTERMAIN BEARING COVERP.T.O.SHAFTFig. 4-15

– 11 –Fig. 4-16

– 12 –5. DISASSEMBLY AND REASSEMBLY5-1 PREPARATIONS AND SUGGESTIONSWhen disassembling the engine, memorize the locations of individual parts so that t

– 13 –5-3 DISASSEMBLY PROCEDURESStep Parts to remove Remarks and procedures Fasteners1 Engine oil drainDrain engine oil by removing plugs located onbo

WING NUTSTEP 5CLEANERCOVERCLEANERELEMENTSTEP 6CLEANER BASEHOSE CLAMPM6 FLANGE BOLT : 3 pcs.BREATHER PIPEHOSE CLAMP– 14 –Step Parts to remove Remarks a

– 15 –Step Parts to remove Remarks and procedures Fasteners7 Blower housingM6 x 12 : 2 pcs.M6 x 14 : 6 pcs.8 Chock control lever and link(1) Remove th

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STEP 9M8 FLANGE BOLT : 2 pcs.CARBURETORGASKET, carburetor– 16 –Step Parts to remove Remarks and procedures Fasteners9CarburetorAt first remove fuel pi

– 17 –Step Parts to remove Remarks and procedures Fasteners10Governor lever and Speed control leverGovernor lever ;Remove bolt and take out lever.Spee

STEP 13STEP 14SPARKPLUG CAPPLUGTERMINALIGNITIONCOILM6 FLANGEBOLT : 2 pcs.HOSE CLAMPHOSE CLAMPHOSE CLAMPPULSE PIPEBRACKET,fuel pumpFUEL PIPEFUEL PUMP a

– 19 –STEP 15STEP 16RING GEARCHARGE COILFLY WHEELCOOLING FANM18 NUT : 1pce.M6 BOLT AND WASHER : 4 pcs.SPRING WASHERWASHERM5 BOLT AND WASHER : 4 pcs.St

– 20 –Step Parts to remove Remarks and procedures Fasteners17Cylinder baffles(#1, #2, #3 & #4)M6 flange bolt x 12 : 10 pcs.STEP 17STEP 18STEP 18M6

– 21 –Step Parts to remove Remarks and procedures Fasteners19 Oil cooler Take out oil hoses M6 Flange bolt : 4 pcs.OIL COOLERHOUSECLAMPHOUSECLAMPOIL

– 22 –Step Parts to remove Remarks and procedures Fasteners20 Intake manifold M8 flange nut : 4 pcs.21 Spark plug NGK : BPR6ES (or CHAMPION : RN9YC)ST

– 23 –Step Parts to remove Remarks and procedures Fasteners22 Rocker cover M6 x 12 : 8 pcs.23Cylinder head and Push rod1. Bolt, pivot2. Rocker armWhen

SEAL-INTAKE VALVE(BLACK)VALVE SPRINGGASKET , breather plateBREATHER PLATEGASKET , breather plateBREATHER COVERM6 FLANGE BOLT : 2 pcs.INTAKE VALVEEXHAU

– 25 –GOVERNORSLEEEVEGOVERNOR GEARGOVERNORGEAR SHAFTWASHER : 2 pcs.GASKETMAIN BEARING COVERM8 FLANGEBOLT : 10 pcs.STEP 25THRUST BEARINGStep Parts to r

CONTENTSSection Title Page1. S

STEP 26TAPPETTAPPETCAMSHAFT– 26 –Step Parts to remove Remarks and procedures Fasteners26Camshaft and tappet Mate the markings both on crankshaft geara

– 27 –Step Parts to remove Remarks and procedures Fasteners27Piston and Connecting rod*Piston pin clip*Piston pin*Piston rings(1) Remove connecting ro

– 28 –Step Parts to remove Remarks and procedures Fasteners29Crankcase*Oil pump*Oil filter*Oil pressure switch*Oil pump filetr*Oil relief spring &

– 29 –5-4 REASSEMBLY PROCEDURES5-4-1 PRECAUTIONS FOR REASSEMBLY1) Clean parts thoroughly before reassembly. Pay most attention to cleanliness of pisto

SEAL-INTAKE VALVE(BLACK)VALVE SPRINGGASKET , breather plateBREATHER PLATEGASKET , breather plateBREATHER COVERM6 FLANGE BOLT : 2 pcs.INTAKE VALVEEXHAU

– 31 –C. PISTON and CONNECTING ROD(1)Install oil ring first, then second ring and top ring. Spread ring only far enough to slip over piston andinto co

– 32 –5-4-3 Re-assembly1) CRANKSHAFTInstall crankshaft onto crankcase.CRANKSHAFTFig. 5-322) PISTON and CONNECTING ROD(1)Install piston and connecting

– 33 –3) TAPPET and CAMSHAFT(1)Apply oil to tappets and install in their originalposition. Push in fully to avoid damage duringcamshaft installation.(

– 34 –5) MAIN BEARING COVER(1)Put a oil seal guide onto PTO shaft portion to avoid damaging the main bearing cover oil seal.(2)Place gasket onto the m

– 35 –(3)Insert push rods into the concave portion of tappet and set the other end to the concave portion of rockerarm adjust screw with valve spring

14) STARTER MOTORInstall starter motor. Tightening torque16.7 - 18.6 N・m(170 - 190 kgf・cm)(12.3 - 13.7 ft・lb.)– 36 –11) BREATHER PIPE and COVERAttach

– 37 –GASKET, mufflerGASKET, mufflerM8 FLANGE NUT : 2 pcs.M8 FLANGENUT : 2 pcs.INTAKE MANIFOLDFig. 5-43BRACKET UNITM6 FLANGEBOLT : 4pcs.OIL COOLERHOSE

– 38 –20) IGNITION COILTemporally fit ignition coil to crankcase.Adjust air gap between ignition coil and flywheelusing a thickness gauge and tighten

– 39 –24) SPEED CONTROL LEVERInstall speed control bracket onto intake manifold.Attach return spring, spacer, friction washer, wing nut, etc. to speed

– 40 –25) ADJUST GOVERNOR SYSTEM(1)Push speed control lever all the way to the highspeed position and fix it by tightening nut. (2)Check that governor

– 41 –29) OIL PRESSURE SWITCHInstall oil pressure switch onto crankcase.Tightening torque5.9 - 9.8 N・m(60 - 100 kgf・cm)(4.3 - 7.2 ft・lb.)OIL PRESSURE

– 42 –UPPER LEVELLOWER LEVELOIL GAUGEOIL GAUGEFig. 5-56OIL GAUGEUPPER LEVELLOWER LEVELOIL GAUGEUPPER LEVELLOWER LEVELFig. 5-5533) ENGINE OILRefill eng

– 43 –6. MAGNETO OPERATION AND FUNCTION The ignition system is pointless flywheel magneto with automatic advancing characteristic.Being different from

– 44 –(2)At lower engine revolution, when the flywheel reached the ignition point the low speed ignition timing controlcircuit operates to run the bas

– 45 –7. LUBRICATION SYSTEM OPERATION AND FUNCTION *Full lubrication system is adopted, in combination with large-size torchoid oil pump and cartridge

– 1 –1. SPECIFICATIONSModel EH72DTypeAir-Cooled, 4-Stroke, V-Twin Cylinder,Horizontal P.T.O. shaft, OHV Gasoline EngineBore×stroke mm (in.) 2 - 84 x 6

– 46 –CamshaftjournalCrankshaftjournal(Flywheel side)Crankshaftjournal(P.T.O. side)CylinderSplashCrankpin &Connecting rodsmall endCrankpin &Co

– 47 –8. CARBURETOR 8-1 OPERATION AND FUNCTION AIRAIR VENTCHOKE VALVESLOW AIR BLEED JETMAIN AIR BLEED JETFLOATFLOAT VALVEFUEL INLET PIPEFUELMAIN NOZZL

– 48 –8-1-1 FLOAT SYSTEM The float system is consists of a float and a needle valve, and maintains a constant fuel level duringengine operation. The f

– 49 –8-2 COMPORNENT PARTS 1. BODY, lower2. GASKET, air horn3. BODY, upper4. LEVER ASS'Y, choke5. RING, choke lever6. SPRING, choke7. COLLAR, cho

– 50 –9. ELECTRIC STARTER9-1 OPERATION AND FUNCTION When key switch is turned ON, lower electric current (M →) flows through coil of magnetic switch a

– 51 –9-2 COMPONENT PARTS 1. STARTING MOTOR ASS'Y2. ARMATURE ASS'Y3. THRUST WASHER KIT4. PINION STOPPER SET5. YOKE ASS'Y6. REAR COVER A

– 52 –10. TROUBLESHOOTING The following three conditions must be fulfilled for satisfactory engine start. (1) The cylinder filled with a proper fuel-a

– 53 –Phenomenon Possible causes Remedy1. Low enginespeed atstarting1) Battery discharged Charge battery2) Poor connection between battery and starter

– 54 –Phenomenon Possible causes Remedy1. Lowcompression1) Loosen spark plug Retighten or replace gasket2) Cylinder head gasket leakage Retighten or r

– 55 –Phenomenon Possible causes Remedy1. Carburetor1) Low idling speed Adjust2) Carburetor slow system passage clogged Check and clean2. Intake syste

– 2 –2. PERFORMANCE2-1 MAXIMUM OUTPUTThe maximum output is the output of an engine with its throttle valve fully opened under the condition that allth

– 56 –10-7 HIGH FUEL CONSUMPTION Phenomenon Possible causes Remedy1. Fuel system1) Over-size main jet Replace2) Needle valve faulty and/or high fuel l

– 57 –10-9 ENGINE MISFIRE Phenomenon Possible causes Remedy1. Ignition system1) Improper spark plug gap or damaged electrode Cealn, adjust or replace

– 58 –11. INSTALLATION Engine life, ease of maintenance and inspection, frequency of checks and repairs, and operating cost alldepend on the way in wh

– 59 –12. SERVICE DATA "STD" in the following table is the parts dimension from the brand new engine or the spare parts.Whereas, "Limit

– 60 –ITEMEH72DSTD LimitCYLINDER* Inside dia.* Roundiness after reboring.* Cylindricity after reboring.STD84.000 - 84.022(3.3071 - 3.3080)To be rebore

– 61 –ITEMEH72DSTD LimitPISTON* Ring groove side clearance* Piston pin hole* Piston pin outside dia.* Clearance between piston and cylinder at skirtar

– 62 –ITEM* Journal dia.E72DCRANKSHAFT* Crankpin outside dia.STD LimitCONNECTING ROD* Big end inside dia.* Clearance between big end and crankpin* Sma

– 63 –ITEMVALVE* Valve stem outside dia.* Clearance between valve stem dia. and valveguide* Valve clearanceEH72DEX.STD LimitCAMSHAFT* Cam height (IN.

– 64 –ITEMEH72DVALVE SPRING FREE LENGTHSTD LimitTAPPET* Stem outside dia.* Guide inside dia.* Tappet guide clearance8.954 - 8.979(0.3525 - 0.3535)8.92

– 65 –ITEMSBreather coverN・・m kgf・・cm ft・・lb.Breather cover 2.9 - 4.9 30 - 50 2.2 - 3.6Carburetor bolts 16.7 - 18.6 170 - 190 12.3 - 13.7Charge coil 1

– 3 –2-4 PERFORMANCE CURVESEH72D2000 2400 2800 3200 360010(13.4)5(6.7)15(20.1)20(26.8)REVOLUTION r.p.mHORSEPOWERkW(HP)TORQUEN-m(kgf-m

– 66 –12-3 OIL GRADE CHARTUse oil classified as SE or higher.Multi-grade oil tends to increase its consumption at high ambient temperature. 5W10W20W#2

– 67 –13. MAINTENANCE AND STORAGE 13-1 DAILY MAINTENANCE Every day before operating engine, check the following items :13-2 PERIODIC MAINTENANCE SCHE

– 68 –Maintenance ItemsEvery 8hours(Daily)Every20hoursEvery50hoursEvery200hoursEvery500hoursEvery1000hoursClean engine and check bolts and nuts× (Dail

– 69 –13-3 ENGINE STORAGE (1)Change the engine oil and perform the daily maintenance items above mentioned.(2)Drain fuel from carburetor float chamber

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– 4 –3. FEATURESHighly rigid structure●High-carbon steel, forged crank shaft●Light-weight , tough alminum forged connectiong rod●Ball-bearing ●Special

– 5 –Fig. 4-1Fig. 4-2Fig. 4-34. GENERAL DESCRIPTION OF ENGINE COMPONENTSROBIN EH72D engine is air-cooled, 4-stroke, twin-cylinder, OHV arrangement gas