Yamaha EH63 Service Manual
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Yamaha EH63 Service Manual

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SERVICE MANUAL
EH63
EH64
EH65
EH72
7D5-28197-E0

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Summary of Contents for Yamaha EH63

  • Page 1 SERVICE MANUAL EH63 EH64 EH65 EH72 7D5-28197-E0...
  • Page 3 EH63/EH64/EH65/EH72 SERVICE MANUAL ©2019 by Yamaha Motor Powered Products Co., Ltd. 1st Edition, February 2019 All rights reserved. Any reprinting or unauthorized use without the written permission of Yamaha Motor Powered Products Co., Ltd. is expressly prohibited.
  • Page 4 This manual was produced by the Yamaha Motor Powered Products Co., Ltd. primarily for use by Yamaha dealers and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one manual. Therefore, anyone who uses this book to perform maintenance and repairs on Yamaha machines should have a basic understanding of mechanics and the techniques to repair these types of machines.
  • Page 5 HOW TO USE THIS MANUAL This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive explanations of all installation, removal, disassembly, assembly, repair and check procedures are laid out with the individual steps in sequential order. •...
  • Page 6 SYMBOLS The following symbols are used in this manual for easier understanding. The following symbols are not relevant to every machine. SYMBOL DEFINITION SYMBOL DEFINITION Filling fluid Lubricant Special tool Tightening torque Wear limit, clearance Engine speed Electrical data Replace the part with a new one. Lithium-soap base grease Molybdenum disulfide grease Engine oil...
  • Page 7 INDEX GENERAL INFORMATION PERIODIC CHECKS AND ADJUSTMENTS ENGINE FUEL ELECTRICAL TROUBLESHOOTING SPECIFICATIONS...

  • Page 8: Table Of Contents

    TABLE OF CONTENTS CYLINDER HEAD GENERAL INFORMATION DECARBONIZATION......2-11 ADJUSTING THE VALVE MACHINE IDENTIFICATION...... 1-1 CLEARANCE........2-12 SERIAL NUMBER ......... 1-1 ENGINE SPEED (EH63K/EH64A/ EH64K/EH65A/EH65B) .......2-14 DIMENSIONS ..........1-2 ENGINE SPEED (EH72A/EH72B/ DIMENSION CHART FOR P.T.O... 1-2 EH72K) ..........2-16 TOP ............1-4 FITTINGS AND FASTENERS....2-18 MOUNTING BASE ........
  • Page 9 FLYWHEEL AND STATOR COIL CHECKING THE OIL PUMP ASSEMBLY ......... 3-20 STRAINER...........3-48 REMOVING THE FLYWHEEL AND ASSEMBLING THE OIL PUMP STATOR COIL ASSEMBLY....3-21 STRAINER...........3-48 CHECKING THE FLYWHEEL AND REMOVING THE FLYWEIGHT STATOR COIL ASSEMBLY....3-22 SHAFT ASSEMBLY AND INSTALLING THE FLYWHEEL AND GOVERNOR FORK ......3-48 STATOR COIL ASSEMBLY....
  • Page 10 CARBURETOR ASSEMBLY ...... 4-4 CHECKING THE ENGINE SWITCH REMOVING THE CARBURETOR (EQUIPPED MODELS ONLY) ....5-8 (EH63K/EH64A/EH64K/EH65A/ CHECKING THE STARTER MOTOR EH65B)..........4-4 OPERATION ..........5-8 DISASSEMBLING THE CHECKING THE WIRE HARNESS ..5-9 CARBURETOR (EH64A/EH65B) ..4-5 ELECTRIC STARTING SYSTEM....5-10 DISASSEMBLING THE REMOVING THE STARTER CARBURETOR (EH63K/EH64K/ MOTOR..........5-10...
  • Page 11 FUEL PUMP AND FUEL HOSE RECTIFIER/REGULATOR AND (EH64A)..........7-13 STARTER MOTOR (EH63K)....7-36 FUEL PUMP AND FUEL HOSE RECTIFIER/REGULATOR AND (EH64K, EXCEPT FOR KOR) ..... 7-14 STARTER MOTOR (EH64A)....7-37 FUEL PUMP AND FUEL HOSE RECTIFIER/REGULATOR AND (EH64K, FOR KOR) ......7-15 STARTER MOTOR (EH64K, EXCEPT FUEL PUMP AND FUEL HOSE FOR KOR) ...........7-38...
  • Page 12 MEMO...

  • Page 13: General Information

    GENERAL INFORMATION MACHINE IDENTIFICATION SERIAL NUMBER The serial number is printed on the label affixed to the position “1” of the multi-purpose engine as shown in the illustration. • The first four digits identify the model, and the remaining digits indicate the production number. •...

  • Page 14: Dimensions

    DIMENSIONS DIMENSIONS DIMENSION CHART FOR P.T.O. mm (in) 80 (3.15) 63 (2.48) 28 (1.1) 19 (0.75) M10 1.25 80 (3.15) 63 (2.48) 30 (1.18) 21 (0.83) 3 (0.12) M10 1.25 99.3 (3.91) 85.5 (3.37) 47 (1.85) 38 (1.5) 7/16-20UNF-2B...
  • Page 15 DIMENSIONS 99.3 (3.91) 85.5 (3.37) 49 (1.93) 40 (1.57) 3 (0.12) 7/16-20UNF-2B 24 (0.94) 19.2 (0.76) 16 (0.63) 5/16-24UNF-2B 19.2 (0.76) 26 (1.02) 18 (0.71) 3 (0.12) 5/16-24UNF-2B UNF: Unified fine thread (Unit: in) A: EH65B, EH72B B: EH65B, EH72B C: EH64A, EH65A, EH72A D: EH64A, EH65A, EH72A E: EH63K, EH64K, EH72K...

  • Page 16: Top

    DIMENSIONS mm (in) 57.1 (2.25) 26 (1.02) MOUNTING BASE mm (in) 90.5 (3.56) 195 (7.68)

  • Page 17: Left Side

    DIMENSIONS LEFT SIDE mm (in) 417.3 (16.43) 99.9 (39.3) 317.4 (12.5) 190.6 (7.5) FRONT mm (in) 477 (18.78) 253.5 (9.98)

  • Page 18: Rear

    DIMENSIONS REAR mm (in) 288.1 (11.34) M8 1.25 144 (5.67) 65 0.2 (2.56 0.01) M8 1.25 7/16-14 UNC 3/8-16 UNC *1: UNC: Unified coarse thread (Unit: in)

  • Page 19: Important Information

    Be sure to use the correct special tool for the job to guard against damage. Oil, grease and seals Be sure to use genuine Yamaha oils, grease and sealers, or the equivalents. Expendable parts Always replace the gaskets, O-rings, cotter pins and cir-...

  • Page 20: All Replacement Parts

    • Make sure that the parts, move smoothly after each sec- tion of the machine is assembled. ALL REPLACEMENT PARTS We recommend the use of genuine Yamaha parts for all replacements. Use oil and/or grease, recommended by Yamaha, for assembly and adjustment.

  • Page 21: Bearings And Oil Seals

    BASIC SERVICE INFORMATION BEARINGS AND OIL SEALS Install the bearing(s) “1” and oil seal(s) “2” with their manu- facture’s marks or numbers facing outward. (In other words, the stamped letters must be on the side exposed to view.) When installing oil seal(s), apply a light coating of lightweight lithium base grease to the seal lip(s).
  • Page 22 BASIC SERVICE INFORMATION Checking the connections Check the leads, couplers, and connectors for stains, rust, moisture, etc. Disconnect: • Lead • Coupler • Connector NOTICE • When disconnecting a coupler, release the coupler lock, hold both sections of the coupler securely, and then disconnect the coupler.
  • Page 23 BASIC SERVICE INFORMATION Check: • All connections Loose connection  Connect properly. • If the pin “1” on the terminal is flattened, bend it up. • After disassembling and assembling a coupler, pull on the leads to make sure that they are installed securely. Connect: •...
  • Page 24 BASIC SERVICE INFORMATION Check: • Continuity (with the digital circuit tester) Digital circuit tester (CD732): 90890-03243 Model 88 Multimeter with tachometer: YU-A1927 • If there is no continuity, clean the terminals. • When checking the wire harness, perform steps (1) to (4).

  • Page 25: Special Tools And Testers

    SPECIAL TOOLS AND TESTERS SPECIAL TOOLS AND TESTERS The proper special tools are necessary for complete and accurate tune-up and assembly. Using the correct special tool will help prevent damage caused by the use of improper tools or improvised techniques. •...
  • Page 26 SPECIAL TOOLS AND TESTERS MEMO 1-14...

  • Page 27: Periodic Checks And Adjustments

    PERIODIC CHECKS AND ADJUSTMENTS INTRODUCTION This chapter includes all information necessary to perform recommended checks and adjustments. These preventive maintenance procedures, if followed, will ensure more reliable machine operation and a longer service life. The need for costly overhaul work will be greatly reduced. This information applies to machines already in service as well as new machines that are being prepared for sale.
  • Page 28 PERIODIC MAINTENANCE/LUBRICATION INTERVALS Every 8 hours Every 50 Every 200 Every 500 Every 1000 Maintenance Items (Daily) hours hours hours hours Check and adjust valve clear-  ance  Replace fuel lines (Every 2 years)  Replace oil lines (Every 2 years) ...

  • Page 29: Periodic Maintenance

    PERIODIC MAINTENANCE PERIODIC MAINTENANCE SPARK PLUGS The following procedure applies to all of the spark plugs. WARNING Check and adjust the areas around the cylinder head after the engine has cooled down completely. Remove: • Spark plug cap • Spark plug NOTICE Before removing the spark plug, use compressed air to clean the cylinder head cover to prevent dirt from...

  • Page 30: Spark Plugs

    PERIODIC MAINTENANCE Before installing the spark plugs, clean the gasket surface and plug surface. Install: • Spark plug Spark plug: 13 N·m (1.3 kgf·m, 9.6 lb·ft) To prevent threads from being damaged, temporally tighten the spark plug to position “a” before tightening it to the specified torque “b”.

  • Page 31: Engine Oil Leakage

    PERIODIC MAINTENANCE Remove: • Fuel filter Check: • Fuel filter Damage/dirt/clogging  Replace. NOTICE Be sure to replace the fuel filter without cleaning it. ENGINE OIL LEAKAGE Place the multi-purpose engine on a level surface. Check the areas outside of the engine for oil leakage. Oil leakage ...

  • Page 32: Replacing The Engine Oil

    PERIODIC MAINTENANCE Check: • Check that the engine oil is between the lower limit “a” and the upper limit “b” of the oil level gauge “1”. Oil level checking steps: a. Place the multi-purpose engine on a level sur- face. b.
  • Page 33 PERIODIC MAINTENANCE a. Remove the oil filter “1” using an oil filter wrench (commercially available product) “2”. Oil filter wrench 65 mm (2.55 in) A. EH63K/EH64A/EH64K/EH65A/EH65B B. EH72A/EH72B/EH72K b. Apply a thin layer of engine oil to the O-ring “3” of the new oil filter.

  • Page 34: Oil Cooler (Eh72A/Eh72B/Eh72K)

    PERIODIC MAINTENANCE Fill: 0 10 30 50 70 90 110130 °F • Engine oil Fill the recommended engine oil from the oil filler SAE 10W-30 hole. Recommended oil brand: SAE 10W-40 YAMALUBE Available oil grade: -20 -10 0 10 20 30 40 50 °C API SE type or higher JASO MA or MB Available viscosity index: 10W-30 or 10W-40...
  • Page 35 PERIODIC MAINTENANCE Remove: • Air filter cover nut “1” • Air filter cover “2” Remove: • Air filter element “3” • Inner element “4” Check: • Air filter element Damage  Replace. Clogged  Wash the element with white kerosene, then dry it thoroughly.

  • Page 36: Muffler

    PERIODIC MAINTENANCE Install: • Inner element • Air filter element • Air filter cover • Air filter cover nut MUFFLER WARNING The engine and muffler will be very hot after the engine has been run. Avoid touching the engine and muffler while they are still hot with any part of your body or clothing during check or repair.

  • Page 37: Breather Hose

    PERIODIC MAINTENANCE Decarbonize: • Spark arrester NOTICE When cleaning with a wire brush, use it softly to avoid damage or scratch the spark arrester. Install: • Muffler (Refer to “INSTALLING THE MUFFLER” on page 3-9.) • Spark arrester • Muffler cap •...

  • Page 38: Adjusting The Valve Clearance

    PERIODIC MAINTENANCE ADJUSTING THE VALVE CLEARANCE The following procedure applies to all of the valves. Remove: • Spark plug cap “1” • Spark plug “2” NOTICE Before removing the spark plug, use compressed air to clean the cylinder head cover to prevent dirt from falling into the engine.
  • Page 39 PERIODIC MAINTENANCE Adjustment steps: a. Loosen the locknut “1” and insert the thickness gauge between the rocker arm and the valve stem end. b. Return or tighten the adjuster “2” and set the valve clearance to the correct value. Move the thickness gauge up and down to check for the proper resistance.

  • Page 40: Engine Speed (Eh63K/Eh64A/ Eh64K/Eh65A/Eh65B)

    PERIODIC MAINTENANCE ENGINE SPEED (EH63K/EH64A/EH64K/EH65A/ EH65B) Warm up the engine for several minutes. Remove: • Air filter cover “1” (Refer to “AIR FILTER” on page 3-3.) Attach: • Digital tachometer “1” Digital tachometer: 90890-06760, YU-39951-B Measure: • High engine speed (with no load) Out of specification ...
  • Page 41 PERIODIC MAINTENANCE Measurement steps: a. Move the throttle lever “1” to the low engine speed position “a”. b. Check that the low engine speed is the specified valued. Adjust: • High engine speed Adjustment steps: a. Start the engine. b. Set the engine speed to the specified value with the throttle lever.

  • Page 42: Engine Speed (Eh72A/Eh72B/Eh72K)

    PERIODIC MAINTENANCE c. Move the carburetor’s throttle stop screw “3” in the direction “a” or “b” until the low engine speed reaches 1300–1500 r/min with no load on the engine. Direction “a” Low engine speed is increased. Direction “b” Low engine speed is decreased. d.
  • Page 43 PERIODIC MAINTENANCE Measurement steps: a. Move the throttle lever “1” to the high engine speed position “a”. b. Check that the high engine speed is the specified valued. Measure: • Low engine speed (with no load) Out of specification  Adjust. Low engine speed: 1900–2100 r/min Measurement steps:...

  • Page 44: Fittings And Fasteners

    PERIODIC MAINTENANCE Adjust: • Low engine speed Adjustment steps: a. Start the engine. b. Check that the governor arm “1” is not pulled by the spring “2”. c. Move the carburetor’s throttle stop screw “3” in the direction “a” or “b” until the low engine speed reaches 1900–2100 r/min with no load on the engine.

  • Page 45: Engine

    ENGINE ENGINE INSPECTION MEASURING THE COMPRESSION PRESSURE The following procedure applies to all of the cylinder heads. Measure the compression pressure after checking and adjusting the valve clearance. Warm up the engine for several minutes. Remove: • Spark plug cap •...
  • Page 46 ENGINE INSPECTION Testing steps (below the minimum specification): a. Squirt a few drops of oil into the cylinder. b. Measure the compression again. Reading Diagnosis Higher than • Worn cylinder, piston, and piston ring(s) without oil • Defective piston, piston ring(s), valve(s), and Same as cylinder head gasket without oil...

  • Page 47: Air Filter

    AIR FILTER AIR FILTER EH63K/EH64A/EH64K/EH65A/EH65B 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the air filter Remove the parts in the order listed. Air filter cover nut Air filter cover Air filter element Air filter plate Breather hose...

  • Page 48: Eh72A/Eh72B/Eh72K

    AIR FILTER EH72A/EH72B/EH72K 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the air filter Remove the parts in the order listed. Air filter cover nut Air filter cover Air filter element Air filter plate Breather hose...

  • Page 49: Muffler

    MUFFLER MUFFLER EH63K/EH72B/EH72K 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) Order Job/Parts to remove Q’ty Remarks...

  • Page 50: Eh64K

    MUFFLER EH64K 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the muffler...

  • Page 51: Eh65B

    MUFFLER EH65B 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the muffler...

  • Page 52: Eh65A/Eh72A

    MUFFLER EH65A/EH72A 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) Order Job/Parts to remove Q’ty...

  • Page 53: Installing The Muffler

    MUFFLER INSTALLING THE MUFFLER Install: • Gasket • Muffler assembly • Muffler nut “1” • Muffler nut “2” • Muffler bolt “3” Temporarily tighten muffler nut “1”, muffler nut “2” and muf- fler bolt “3”. Tighten: • Muffler nut “1” •...

  • Page 54: Oil Cooler And Oil Filter

    OIL COOLER AND OIL FILTER OIL COOLER AND OIL FILTER 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) Except EH72A/EH72B/EH72K 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 8 N ・...

  • Page 55: Removing The Oil Cooler (Eh72A/Eh72B/Eh72K)

    OIL COOLER AND OIL FILTER REMOVING THE OIL COOLER (EH72A/EH72B/ EH72K) Remove: • Oil hose 1 • Oil hose 2 • Oil cooler • Adapter • Oil pressure switch CHECKING THE OIL COOLER (EH72A/EH72B/ EH72K) Check: • Oil cooler “1” •...
  • Page 56 OIL COOLER AND OIL FILTER Install: • Bracket Bracket bolt: 8 N·m (0.8 kgf·m, 5.9 lb·ft) • Oil cooler Oil cooler bolt: 8 N·m (0.8 kgf·m, 5.9 lb·ft) • Oil hose 2 • Oil hose 1 • Oil filter • Oil pressure switch Oil pressure switch: 8 N·m (0.8 kgf·m, 5.9 lb·ft) 3-12...

  • Page 57: Rectifier/Regulator

    RECTIFIER/REGULATOR RECTIFIER/REGULATOR 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the rectifier/regulator Remove the parts in the order listed. Rectifier/regulator Connector Disconnect. 3-13...

  • Page 58: Case And Fan

    CASE AND FAN CASE AND FAN 4.5 N ・ m (0.45 kgf ・ m, 3.3 lb ・ ft) 2.5 N ・ m (0.25 kgf ・ m, 1.8 lb ・ ft) 4.5 N ・ m (0.45 kgf ・ m, 3.3 lb ・ ft) 2.5 N ・...

  • Page 59: Removing The Case And Fan

    CASE AND FAN REMOVING THE CASE AND FAN Remove: • Air filter (Refer to “AIR FILTER” on page 3-3.) Remove: • Fan case “1” • Fan “2” CHECKING THE CASE AND FAN Check: • Fan case “1” • Fan “2” Damage ...

  • Page 60: Installing The Case And Fan

    CASE AND FAN INSTALLING THE CASE AND FAN Install: • Fan “1” • Fan bolt Fan bolt: 4.5 N·m (0.45 kgf·m, 3.3 lb·ft) Install: • Fan case “2” • Fan case bolt (side) • Fan case bolt (front) Fan case bolt (side): 2.5 N·m (0.25 kgf·m, 1.8 lb·ft) Fan case bolt (front): 4.5 N·m (0.45 kgf·m, 3.3 lb·ft)

  • Page 61: Cylinder Covers

    CYLINDER COVERS CYLINDER COVERS CYLINDER COVER 1 AND CYLINDER COVER 2 13 N ・ m (1.3 kgf ・ m, 9.6 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) Order Job/Parts to remove Q’ty...

  • Page 62: Cylinder Cover 3

    CYLINDER COVERS CYLINDER COVER 3 13 N ・ m (1.3 kgf ・ m, 9.6 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) Order Job/Parts to remove Q’ty...

  • Page 63: Tci Units, Flywheel And Stator Coil Assembly

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY TCI UNITS 13 N ・ m (1.3 kgf ・ m, 9.6 lb ・ ft) 13 N ・ m (1.3 kgf ・ m, 9.6 lb ・ ft) 8 N ・...

  • Page 64: Flywheel And Stator Coil Assembly

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY FLYWHEEL AND STATOR COIL ASSEMBLY 3.4 N ・ m (0.34 kgf ・ m, 2.5 lb ・ ft) 3.4 N ・ m (0.34 kgf ・ m, 2.5 lb ・ ft) 3.4 N ・ m (0.34 kgf ・ m, 2.5 lb ・ ft) 110 N ・...

  • Page 65: Removing The Flywheel And Stator Coil Assembly

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY REMOVING THE FLYWHEEL AND STATOR COIL ASSEMBLY Remove: • Air filter (Refer to “AIR FILTER” on page 3-3.) Remove: • Fan case and fan (Refer to “CASE AND FAN” on page 3-14.) Remove: •...

  • Page 66: Checking The Flywheel And Stator Coil Assembly

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY Flywheel puller: 90890-01362 Heavy duty puller: YU-33270-B Remove: • Stator coil assembly CHECKING THE FLYWHEEL AND STATOR COIL ASSEMBLY Check: • Flywheel “1” • Stator coil assembly “2” Damage  Replace. INSTALLING THE FLYWHEEL AND STATOR COIL ASSEMBLY Install: •...

  • Page 67: Installing The Tci Units

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY Sheave holder: 90890-01701 Primary clutch holder: YS-01880-A Install: • TCI unit • TCI unit bolt (Refer to “INSTALLING THE TCI UNITS” on page 3-23.) TCI unit bolt: 8 N·m (0.8 kgf·m, 5.9 lb·ft) Install: •...
  • Page 68 TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY Measure: • TCI unit air gap Out of specification  Adjust. Thickness gauge: 90890-03268 Feeler gauge set: YU-26900-9 TCI unit air gap: 0.3–0.5 mm (0.011–0.019 in) Adjust: • TCI unit air gap Adjustment steps: a.

  • Page 69: Engine Switch And Oil Warning Light (Equipped Models Only)

    ENGINE SWITCH AND OIL WARNING LIGHT (EQUIPPED MODELS ONLY) ENGINE SWITCH AND OIL WARNING LIGHT (EQUIPPED MODELS ONLY) Order Job/Parts to remove Q’ty Remarks Removing the engine switch and oil Remove the parts in the order listed. warning light Washer Engine switch cover Engine switch Spring washer...

  • Page 70: Cylinder Head Covers, Cylinder Heads

    CYLINDER HEAD COVERS, CYLINDER HEADS CYLINDER HEAD COVERS, CYLINDER HEADS CYLINDER HEAD #1 25 N ・ m (2.5 kgf ・ m, 18 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 45 N ・ m (4.5 kgf ・ m, 33 lb ・ ft) 3.9 N ・...
  • Page 71 CYLINDER HEAD COVERS, CYLINDER HEADS 25 N ・ m (2.5 kgf ・ m, 18 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 45 N ・ m (4.5 kgf ・ m, 33 lb ・ ft) 3.9 N ・...
  • Page 72 CYLINDER HEAD COVERS, CYLINDER HEADS 25 N ・ m (2.5 kgf ・ m, 18 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 45 N ・ m (4.5 kgf ・ m, 33 lb ・ ft) 3.9 N ・...

  • Page 73: Cylinder Head #2

    CYLINDER HEAD COVERS, CYLINDER HEADS CYLINDER HEAD #2 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 25 N ・ m (2.5 kgf ・ m, 18 lb ・ ft) 45 N ・...
  • Page 74 CYLINDER HEAD COVERS, CYLINDER HEADS 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 25 N ・ m (2.5 kgf ・ m, 18 lb ・ ft) 45 N ・...
  • Page 75 CYLINDER HEAD COVERS, CYLINDER HEADS 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 25 N ・ m (2.5 kgf ・ m, 18 lb ・ ft) 45 N ・...

  • Page 76: Checking The Rocker Arms

    CYLINDER HEAD COVERS, CYLINDER HEADS CHECKING THE ROCKER ARMS Check: • Rocker arm “1” Wear/damage/cracks  Replace. REMOVING THE CYLINDER HEADS The following procedure applies to all of the cylinder heads. Remove: • Cylinder head Set the piston at TDC (top-dead-center) on the compres- sion stroke.

  • Page 77: Installing The Cylinder Head Assemblies

    CYLINDER HEAD COVERS, CYLINDER HEADS Warpage limit: 0.1 mm (0.0039 in) Out of specifications  Resurface or replace. INSTALLING THE CYLINDER HEAD ASSEMBLIES Install: • Cylinder head assembly #1 • Cylinder head bolt “1”–“4” Tighten the bolts to the specified torque in two steps and in order from “1”–“4”.

  • Page 78: Valves

    VALVES VALVES CYLINDER HEAD #1 Order Job/Parts to remove Q’ty Remarks Removing the valves Remove the parts in the order listed. Refer to “CYLINDER HEAD COVERS, CYL- Cylinder head assembly INDER HEADS” on page 3-26. Valve cotter Valve spring retainer Valve spring Valve spring seat Exhaust side only...

  • Page 79: Cylinder Head #2

    VALVES CYLINDER HEAD #2 Order Job/Parts to remove Q’ty Remarks Removing the valves Remove the parts in the order listed. Refer to “CYLINDER HEAD COVERS, CYL- Cylinder head assembly INDER HEADS” on page 3-26. Valve cotter Valve spring retainer Valve spring Valve spring seat Exhaust side only Exhaust valve...

  • Page 80: Removing The Valves And Valve Springs

    VALVES REMOVING THE VALVES AND VALVE SPRINGS The following procedure applies to all of the valves, valve springs and related components. Remove the parts below from the intake side. • Valve cotter “1” • Valve spring retainer “2” • Valve spring “3” •...
  • Page 81 VALVES Valve stem length (Intake): 79.8 mm (3.1417 in) Valve stem length (Exhaust): 80.3 mm (3.1614 in) Valve head diameter (Intake): 34.99–35.01 mm (1.3775–1.3783 in) Valve head diameter (Exhaust): 30.9–31.1 mm (1.2165–1.2244 in) Out of specifications  Replace. Measure: • Valve stem diameter “a” Valve stem diameter (Intake): 5.970–5.985 mm (0.2350–0.2356 in) Valve stem diameter (Exhaust):...

  • Page 82: Checking The Valve Seats

    VALVES Check: • Valve spring contact surface “a” More than 2/3 of the contact surface does not con- tact  Replace. CHECKING THE VALVE SEATS The following procedure applies to all of the valves and valve seats. Remove carbon deposits from the valve face and valve seat.

  • Page 83: Valve Lapping

    VALVES Measure: • Valve seat contact width “a” Make sure that the contact width along the entire valve seat is within specifications. Valve seat contact width (Intake): 0.7–1.0 mm (0.0275–0.0393 in) Valve seat contact width (Exhaust): 0.7–1.0 mm (0.0275–0.0393 in) Limit (Intake): 2.0 mm (0.0787 in) Limit (Exhaust):...

  • Page 84: Installing The Valves And Valve Springs

    VALVES INSTALLING THE VALVES AND VALVE SPRINGS The following procedure applies to all of the valves, valve springs and related components. Install the parts below on the intake side. • Intake valve “1” • Valve stem seal “2” • Valve spring “3” •...

  • Page 85: Oil Pump

    OIL PUMP OIL PUMP 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the oil pump Remove the parts in the order listed. Refer to “CYLINDER HEAD COVERS, CYL- Cylinder head assembly INDER HEADS”...

  • Page 86: Disassembling The Oil Pump

    OIL PUMP DISASSEMBLING THE OIL PUMP Remove: • Oil pump cover “1” Remove: • O-ring “2” • Outer rotor “3” • Inner rotor “4” CHECKING THE OIL PUMP Check: • Inner rotor “1” • Outer rotor “2” Cracks/damage/wear  Replace. Measure: •...
  • Page 87 OIL PUMP Lubricate: • Inner rotor • Outer rotor Recommended lubricant: Engine oil Install: • O-ring “1” • Outer rotor “2” • Inner rotor “3” • Oil pump cover “4” • Oil pump cover bolt The oil pump cover should be installed with the arrow mark “a”...

  • Page 88: Pistons, Camshaft, Crankcase, And Crankshaft

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT CRANKCASE COVER 25 N ・ m (2.5 kgf ・ m, 18 lb ・ ft) (10) 13 N ・ m (1.3 kgf ・ m, 9.6 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the crankcase cover...

  • Page 89: Camshaft

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT CAMSHAFT Order Job/Parts to remove Q’ty Remarks Removing the camshaft Remove the parts in the order listed. Camshaft Valve lifter 3-45...

  • Page 90: Pistons And Crankshaft

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT PISTONS AND CRANKSHAFT 25 N ・ m (2.5 kgf ・ m, 18 lb ・ ft) 25 N ・ m (2.5 kgf ・ m, 18 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the pistons and crankshaft Remove the parts in the order listed.

  • Page 91: Crankcase

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT CRANKCASE 21 N ・ m (2.1 kgf ・ m, 15 lb ・ ft) 21 N ・ m (2.1 kgf ・ m, 15 lb ・ ft) 3.8 N ・ m (0.38 kgf ・ m, 2.8 lb ・ ft) 20 N ・...

  • Page 92: Checking The Relief Valve

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT CHECKING THE RELIEF VALVE Check: • Relief valve Damage/wear/seizure  Replace. Relief valve operating pressure: 373 kPa (3.73 kgf/cm², 54.09 psi) ASSEMBLING THE RELIEF VALVE Install: • Relief valve Relief valve: 20 N·m (2.0 kgf·m, 15 lb·ft) CHECKING THE OIL PUMP STRAINER Check: •...

  • Page 93: Disassembling The Flyweight Shaft Assembly

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Remove: • Flyweight shaft assembly “1” • Washer “2” • Thrust bearing “3” • Washer “4” Remove the flyweight shaft assembly by tapping the weight shaft from outside of the crankcase cover. DISASSEMBLING THE FLYWEIGHT SHAFT ASSEMBLY Remove: •...

  • Page 94: Assembling The Flyweight Shaft Assembly

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT ASSEMBLING THE FLYWEIGHT SHAFT ASSEMBLY Install: • Weight shaft “1” • Collar “2” • Weights “3” • Flyweight shafts “4” INSTALLING THE FLYWEIGHT SHAFT ASSEMBLY AND GOVERNOR FORK Install: • Washer “1” • Thrust bearing “2” •...

  • Page 95: Removing The Camshaft And Valve Lifters

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT REMOVING THE CAMSHAFT AND VALVE LIFTERS The following procedure applies to all of the camshaft and valve lifters. Remove: • Camshaft “1” • Since there are two types of camshafts, refer to the illus- tration and check the camshaft gear mark. •...
  • Page 96 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Check: • Camshaft lobe dimensions “a” Camshaft lobe dimensions: Lobe height “a” (Intake): 35.26–35.46 mm (1.3881–1.3960 in) (EH63K/EH64A/EH64K/EH65A/EH65B) 35.56–35.76 mm (1.3999–1.4078 in) (EH72A/EH72B/EH72K) Limit: 35.16 mm (1.3842 in) (EH63K/EH64A/ EH64K/EH65A/EH65B) 35.46 mm (1.3960 in) (EH72A/EH72B/ EH72K) Lobe height “a”...

  • Page 97: Checking The Valve Lifters

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT CHECKING THE VALVE LIFTERS Check: • Valve lifter Damage  Replace. INSTALLING THE VALVE LIFTERS AND CAMSHAFT Install: • Intake valve lifters “1” • Exhaust valve lifters “2” Install: • Camshaft “1” NOTICE • Since there are two types of camshafts, refer to the illustration and check the camshaft gear mark.

  • Page 98: Installing The Crankcase Cover

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT INSTALLING THE CRANKCASE COVER Install: • Crankcase cover • Crankcase cover bolts “1”–“10” Crankcase cover bolt: 25 N·m (2.5 kgf·m, 18 lb·ft) CHECKING THE CYLINDERS AND PISTONS Check: • Piston wall • Cylinder wall Vertical scratches  Replace the cylinder, and replace the piston and piston rings as a set.
  • Page 99 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Measure cylinder bore “C” by taking side-to-side and front- to-back measurements of the cylinder. Bore: 80.000–80.019 mm (3.1496–3.1503 in) (EH63K/EH64A/EH64K/EH65A/EH65B) 84.000–84.022 mm (3.3070–3.3079 in) (EH72A/EH72B/EH72K) Warpage limit: 0.1 mm (0.0039 in) “C” = maximum of D b.

  • Page 100: Checking The Crankcase

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Piston-to-cylinder clearance: 0.012–0.051 mm (0.0004–0.0020 in) (EH63K/ EH64A/EH64K/EH65A/EH65B) 0–0.042 mm (0–0.0016 in) (EH72A/EH72B/ EH72K) Limit: 0.15 mm (0.0059 in) f. If out of specification, replace the crankcase assembly, and replace the piston and piston rings as a set.

  • Page 101: Checking The Piston Rings

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Check: • Check that the piston pin enters smoothly into the piston pin hole. If the piston pin fits too tight into the piston, check the pis- ton pin hole. If there is any protrusion, use a knife or scraper to gently remove it so that piston pin can be pushed in smoothly with your fingers.

  • Page 102: Checking The Crankshaft

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Top ring End gap (installed): 0.20–0.40 mm (0.0079–0.0157 in) Limit: 1.50 mm (0.0590 in) 2nd ring End gap (installed): 0.20–0.40 mm (0.0079–0.0157 in) Limit: 1.50 mm (0.0590 in) Oil ring End gap (installed): 0.20–0.70 mm (0.0079–0.0276 in) Limit: 1.50 mm (0.0590 in) CHECKING THE CRANKSHAFT...

  • Page 103: Installing The Pistons And Piston Rings

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Place a piece of Plastigauge® “1” on the crank pin horizontally. Wipe off oil thoroughly from the crankshaft, connecting rod, and connecting rod cap. Install: • Connecting rod “1” • Connecting rod cap “2” Connecting rod cap bolt: 25 N·m (2.5 kgf·m, 18 lb·ft) INSTALLING THE PISTONS AND PISTON RINGS The following procedure applies to all of the pistons and...

  • Page 104: Installing The Crankshaft

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Install: • Piston “1” • Piston pin “2” • Piston pin circlip “3” • For the EH63K/EH64A/EH64K/EH65A/EH65B, install so that the assembly direction mark “a” side faces the flywheel side. • There is no installation direction mark on the EH72A/ EH72B/EH72K, and either side of the piston may face the flywheel side.
  • Page 105 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Check: • Piston with the connecting rod “1” position For cylinder #1, install so that the number “1” “a” on the connecting rod faces the crankcase cover side, and for cyl- inder #2, install so that the number “2” “b” on the connect- ing rod faces the crankcase cover side.

  • Page 106: Selecting The Crankshaft Shim

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Install: • Connecting rod cap #2 “1” • Connecting rod cap bolts #2 “2” Connecting rod cap bolt: 25 N·m (2.5 kgf·m, 18 lb·ft) • Make sure that the “ ” mark “a” on the connecting rod is aligned with the “...
  • Page 107 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Install a depth gauge (commercially available product) “8” for measurement on crankshaft “6” and crankcase “7”. Measure dimension 1 on the “a” side of the depth gauge, dimension 2 on the “b” side. Place a horizontal bar or a base on the crankcase and install a depth gauge, as shown in the illustration.
  • Page 108 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT MEMO 3-64...

  • Page 109: Fuel

    FUEL FUEL PUMP EH63K/EH64A/EH64K/EH65A/EH65B 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 5 N ・ m (0.5 kgf ・ m, 3.7 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the fuel pump Remove the parts in the order listed. Fuel filter Fuel hose Fuel pump...

  • Page 110: Eh72A/Eh72B/Eh72K

    FUEL PUMP EH72A/EH72B/EH72K 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 5 N ・ m (0.5 kgf ・ m, 3.7 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the fuel pump Remove the parts in the order listed. Fuel filter Fuel hose Fuel pump...

  • Page 111: Checking The Fuel Pump

    FUEL PUMP CHECKING THE FUEL PUMP Check: • Fuel hose “1” • Fuel hose (carburetor side) “2” • Pulsar hose “3” • Fuel pump “4” Cracks/damage  Replace. Check: • Fuel pump operation Checking steps: a. Connect a manual vacuum pump (vacuum/pres- sure pump gauge set) “1”...

  • Page 112: Carburetor Assembly

    CARBURETOR ASSEMBLY CARBURETOR ASSEMBLY REMOVING THE CARBURETOR (EH63K/EH64A/EH64K/EH65A/EH65B) 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) 4.0 N ・ m (0.40 kgf ・ m, 3.0 lb ・ ft) 8 N ・...

  • Page 113: Disassembling The Carburetor (Eh64A/Eh65B)

    CARBURETOR ASSEMBLY DISASSEMBLING THE CARBURETOR (EH64A/EH65B) Order Job/Parts to remove Q’ty Remarks Disassembling the carburetor Disassemble the parts in the order listed. Drain screw/spring Throttle stop screw/spring Float pin screw Float pin Float valve Float Slow jet Main jet Gasket Solenoid valve Lead assembly...
  • Page 114 CARBURETOR ASSEMBLY Order Job/Parts to remove Q’ty Remarks Gasket Screw O-ring...

  • Page 115: Disassembling The Carburetor (Eh63K/Eh64K/Eh65A)

    CARBURETOR ASSEMBLY DISASSEMBLING THE CARBURETOR (EH63K/EH64K/EH65A) Order Job/Parts to remove Q’ty Remarks Disassembling the carburetor Disassemble the parts in the order listed. Drain screw/spring Throttle stop screw/spring Float pin screw Float pin Float valve Float Slow jet Main jet Gasket Solenoid valve Plug...
  • Page 116 CARBURETOR ASSEMBLY Order Job/Parts to remove Q’ty Remarks Gasket Screw O-ring...

  • Page 117: Removing The Carburetor (Eh72A/Eh72B/Eh72K)

    CARBURETOR ASSEMBLY REMOVING THE CARBURETOR (EH72A/EH72B/EH72K) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 4.0 N ・ m (0.40 kgf ・ m, 3.0 lb ・ ft) 8 N ・...

  • Page 118: Disassembling The Carburetor (Eh72A/Eh72B/Eh72K)

    CARBURETOR ASSEMBLY DISASSEMBLING THE CARBURETOR (EH72A/EH72B/EH72K) 3.9 N ・ m (0.39 kgf ・ m, 2.9 lb ・ ft) 2.0 N ・ m (0.20 kgf ・ m, 1.5 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Disassembling the carburetor Disassemble the parts in the order listed. Drain screw/spring Float chamber Screw...

  • Page 119: Removing The Carburetor Assembly

    CARBURETOR ASSEMBLY REMOVING THE CARBURETOR ASSEMBLY Remove: • Spring • Governor arm • Throttle lever assembly • Link rod/spring Remove: • Gasket “1” • Carburetor assembly “2” • Joint (EH72A/EH72B/EH72K) “3” A. EH63K/EH64A/EH64K/EH65A/EH65B B. EH72A/EH72B/EH72K CHECKING THE CARBURETOR Check: • Carburetor assembly Cracks/damage ...

  • Page 120: Installing The Carburetor Assembly

    CARBURETOR ASSEMBLY INSTALLING THE CARBURETOR ASSEMBLY Install: • Gasket “1” • Carburetor assembly “2” • Joint (EH72A/EH72B/EH72K) “3” • Carburetor assembly bolt (EH63K/EH64A/EH64K/ EH65A/EH65B) • Carburetor assembly nut (EH72A/EH72B/EH72K) A. EH63K/EH64A/EH64K/EH65A/EH65B B. EH72A/EH72B/EH72K Carburetor assembly bolt (EH63K/EH64A/ EH64K/EH65A/EH65B): 18 N·m (1.8 kgf·m, 13 lb·ft) Carburetor assembly nut (EH72A/EH72B/ EH72K): 8 N·m (0.8 kgf·m, 5.9 lb·ft)

  • Page 121: Adjusting The Governor

    CARBURETOR ASSEMBLY ADJUSTING THE GOVERNOR Adjust: • Governor Adjustment steps: a. Loosen the governor arm bolt “1”. b. Turn the governor arm “2” counterclockwise until it stops so that the throttle lever is fully open. c. Turn the governor fork “3” counterclockwise until it stops.

  • Page 122: Intake Manifold

    INTAKE MANIFOLD INTAKE MANIFOLD EH63K/EH64A/EH64K/EH65A/EH65B 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the intake manifold Remove the parts in the order listed. Muffler Refer to “MUFFLER”...

  • Page 123: Eh72A/Eh72B/Eh72K

    INTAKE MANIFOLD EH72A/EH72B/EH72K 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) Order Job/Parts to remove Q’ty Remarks...

  • Page 124: Removing The Intake Manifold

    INTAKE MANIFOLD REMOVING THE INTAKE MANIFOLD Remove: • Intake manifold “1” • Gasket “2” A. EH63K/EH64A/EH64K/EH65A/EH65B B. EH72A/EH72B/EH72K CHECKING THE INTAKE MANIFOLD Check: • Intake manifold Cracks/damage  Replace. INSTALLING THE INTAKE MANIFOLD Install: • Gasket “1” • Intake manifold “2” A.
  • Page 125 INTAKE MANIFOLD Install: • Intake manifold nut A. EH63K/EH64A/EH64K/EH65A/EH65B B. EH72A/EH72B/EH72K Intake manifold nut: 18 N·m (1.8 kgf·m, 13 lb·ft) 4-17...

  • Page 126: Electrical

    ELECTRICAL CIRCUIT DIAGRAM...
  • Page 127 CIRCUIT DIAGRAM 1. Carburetor 7. Starter motor 2. Oil pressure switch 8. Spark plug 3. Oil warning light (option) 9. TCI unit #1 4. Engine switch (option) 10.Rectifier/regulator 5. Battery (12 V, option) 11.Stator coil assembly 6. Tachometer/hour meter (option) 12.TCI unit #2 13.Starter relay Color code...

  • Page 128: Electrical Components

    ELECTRICAL COMPONENTS ELECTRICAL COMPONENTS...
  • Page 129 ELECTRICAL COMPONENTS 1. TCI unit 2. Stator coil assembly 3. Oil pressure switch 4. Engine switch (equipped models only) 5. Rectifier/regulator 6. Starter motor...

  • Page 130: Checking The Switch Continuity

    ELECTRICAL COMPONENTS CHECKING THE SWITCH CONTINUITY Check each switch for continuity with the tester. If the con- tinuity reading is incorrect, check the wiring connections O.L” and if necessary, replace the switch. NOTICE Never insert the tester probes into the coupler termi- Ω”...

  • Page 131: Checking The Ignition Spark Gap

    ELECTRICAL COMPONENTS Connect: • Digital circuit tester (Connect between the engine body and oil pressure switch terminal.) Digital circuit tester (CD732): 90890-03243 Model 88 Multimeter with tachometer: YU-A1927 Check: • Oil pressure switch continuity No continuity  Replace the oil pressure switch. CHECKING THE IGNITION SPARK GAP Check: •...

  • Page 132: Checking The Air Gap

    ELECTRICAL COMPONENTS d. Set the engine switch to “RUN”. e. Measure the ignition spark gap “a”. CHECKING THE AIR GAP Check: • Measure the gap between the flywheel and TCI unit. Out of specification  Adjust the TCI unit. (Refer to “INSTALLING THE TCI UNITS” on page 3-23.) TCI unit air gap: 0.3–0.5 mm (0.011–0.019 in)

  • Page 133: Checking The Engine Switch (Equipped Models Only)

    ELECTRICAL COMPONENTS a. Remove the ignition coil (TCI unit). b. Connect the digital circuit tester () to the sec- ondary terminal. Digital circuit tester (CD732): 90890-03243 Model 88 Multimeter with tachometer: YU-A1927 • Positive tester probe  High tension cord “1” •...

  • Page 134: Checking The Wire Harness

    ELECTRICAL COMPONENTS Does not operate  Perform the electric starting system troubleshooting, starting with step 3. (Refer to “ELECTRIC STARTING SYSTEM” on page 6-2.) a. Prepare the battery and jumper lead, connect the jumper lead “1” to the (+) side of the battery and the starter motor terminal as shown in the illus- tration, and ground the (–) side of the battery to the main body of the starter motor.

  • Page 135: Electric Starting System

    ELECTRIC STARTING SYSTEM ELECTRIC STARTING SYSTEM REMOVING THE STARTER MOTOR 18 N ・ m (1.8 kgf ・ m, 13 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the starter motor Remove the parts in the order listed. Refer to “RECTIFIER/REGULATOR” on page Rectifier/regulator 3-13.

  • Page 136: Charging System

    CHARGING SYSTEM CHARGING SYSTEM CHECKING THE STATOR COIL ASSEMBLY Remove: • Stator coil assembly (Refer “FLYWHEEL STATOR COIL ASSEMBLY” on page 3-20.) Check: • Stator coil assembly resistance Out of specification  Replace. Stator coil assembly resistance: 0.2  ± 20 % at 20 C (68 F) a.
  • Page 137 CHARGING SYSTEM Check: • Rectifier/regulator resistance Out of specification  Replace. • Measure the resistance value between terminals a–d. • Refer to the table for the resistance value between termi- nals. A. Negative terminal B. Positive terminal Digital circuit tester (CD732): 90890-03243 Model 88 Multimeter with tachometer: YU-A1927...
  • Page 138 CHARGING SYSTEM MEMO 5-13...

  • Page 139: Troubleshooting

    TROUBLESHOOTING ENGINE DOES NOT START Checking steps Possible remedy Check the engine oil level. Add the oil if it is insufficient. (Refer to “ENGINE OIL LEVEL” on page 2-5.) Check the fuel level. Add the fuel if it is insufficient. Check if the fuel has deteriorated.

  • Page 140: Electric Starting System

    ELECTRIC STARTING SYSTEM ELECTRIC STARTING SYSTEM Checking steps Possible remedy • Clean the battery terminals. Check the battery (option). • Recharge or replace the battery. Check the starter motor operation. If the starter motor operates normally, (Refer to “CHECKING THE STARTER MOTOR OPERA- the starter motor is OK.

  • Page 141: Engine Speed Does Not Increase

    ENGINE SPEED DOES NOT INCREASE ENGINE SPEED DOES NOT INCREASE Checking steps Possible remedy Check the spark plug for dirt and check the spark plug gap. Clean, adjust, or replace the spark plug. Check the air filter element for dirt. Clean.

  • Page 142: Engine Speed Is Uneven

    ENGINE SPEED IS UNEVEN ENGINE SPEED IS UNEVEN Checking steps Possible remedy Check the fuel level. Add the fuel if it is insufficient. Check if the fuel has deteriorated. Replace the fuel. Check the spark plug for dirt and check the spark plug gap. Clean, adjust, or replace the spark plug. Check the carburetor turn out and float height.

  • Page 143: Governor Operation

    GOVERNOR OPERATION GOVERNOR OPERATION Checking steps Possible remedy Check that the governor link operate smoothly. Adjust or replace. Check that the governor spring is stretched. Replace. Check the governor adjustment. Adjust. (Refer to “ADJUSTING THE GOVERNOR” on page 4-13.) Check the governor weight and governor bushing function. (Refer to “CHECKING THE FLYWEIGHT SHAFT ASSEM- Adjust or replace.
  • Page 144 GOVERNOR OPERATION MEMO...

  • Page 145: Specifications

    SPECIFICATIONS GENERAL SPECIFICATIONS Model: EH63K EH64K EH64A EH65B EH65A EH72A EH72B EH72K Model code: 7D3B00 (EH63K) 7D4B00 (EH64K) 7D4J00 (EH64A) 7D5200 (EH65B) 7D5J00 (EH65A) 7B3100 (EH72A) 7B3201 (EH72B) 7B3B00 (EH72K) Dimensions: Overall length 317 mm (12.48 in) Overall width 477 mm (18.77 in) Overall height 475 mm (18.70 in) Dry weight...
  • Page 146 GENERAL SPECIFICATIONS Engine oil quantity 1.55 L (1.64 US qt, 1.36 Imp.qt) (including in oil filter) Recommended oil brand YAMALUBE Available oil grade API SE type or higher JASO MA or MB Available viscosity index 10W-30 or 10W-40 Oil filter type Cartridge type Lubrication system Forced pressure feeding type...

  • Page 147: Maintenance Specifications

    MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Piston: Piston-to-cylinder clearance 0.012–0.051 mm (0.0004–0.0020 in) (EH63K/EH64K/ EH64A/EH65B/EH65A) 0–0.042 mm (0–0.0016 in) (EH72A/EH72B/EH72K) Limit 0.15 mm (0.0059 in) Piston diameter 79.960–79.980 mm (3.1480–3.1488 in) (EH63K/EH64K/ EH64A/EH65B/EH65A) 83.980–84.000 mm (3.3062–3.3070 in) (EH72A/EH72B/ EH72K) Limit 79.878 mm (3.1447 in) (EH63K/EH64K/EH64A/EH65B/ EH65A) 83.890 mm (3.3027 in) (EH72A/EH72B/EH72K) Measuring point (from piston...
  • Page 148 MAINTENANCE SPECIFICATIONS Oil ring Type Combination Dimensions 2.8 × 3.0 mm (0.1102 × 0.1181 in) (EH63K/EH64K/ EH64A/EH65B/EH65A) 3.0 × 3.2 mm (0.1181 × 0.1259 in) (EH72A/EH72B/ EH72K) End gap (installed) 0.20–0.70 mm (0.0079–0.0276 in) Limit 1.50 mm (0.0590 in) Cylinder head: Warpage limit 0.1 mm (0.0039 in) Cylinder:...
  • Page 149 MAINTENANCE SPECIFICATIONS Valve: Valve dimensions Valve head diameter (Intake) 34.99–35.01 mm (1.3775–1.3783 in) Valve head diameter 30.9–31.1 mm (1.2165–1.2244 in) (Exhaust) Valve stem diameter (Intake) 5.970–5.985 mm (0.2350–0.2356 in) Valve stem diameter (Exhaust) 5.970–5.985 mm (0.2350–0.2356 in) Limit (Intake) 5.940 mm (0.2338 in) Limit (Exhaust) 5.940 mm (0.2338 in) Valve stem length (Intake)
  • Page 150 MAINTENANCE SPECIFICATIONS Oil pump: Inner-rotor-to-outer-rotor-tip 0.15 mm (0.0059 in) clearance Relief valve operating pressure 373 kPa (3.73 kgf/cm², 54.09 psi) Carburetor: Type 7D3B (EH63K) 7D4B (EH64K) 7D4J (EH64A) 7D52 (EH65B) 7D5J (EH65A) 7B31 (EH72A) 7B32 (EH72B) 7B3B (EH72K) I.D. mark 7D3-14101-01 (EH63K) 7D4-14101-01 (EH64K) 7D4-14101-11 (EH64A)

  • Page 151: Electrical

    MAINTENANCE SPECIFICATIONS ELECTRICAL Ignition system: Ignition system Ignition timing at 3600 r/min BTDC 26.5 ± 2 Ignition coil: 0–5  Primary coil resistance Secondary coil resistance 8–16 k TCI unit air gap 0.3–0.5 mm (0.011–0.019 in) Minimum ignition spark gap 6.0 mm (0.2362 in) Charging system: 0.2 ...
  • Page 152 TIGHTENING TORQUES TIGHTENING TORQUES Item Thread size Tightening torque Air filter plate bolt M6 × 1.0 8 N·m (0.8 kgf·m, 5.9 lb·ft) Intake manifold nut M8 × 1.25 18 N·m (1.8 kgf·m, 13 lb·ft) Muffler bracket bolt M6 × 1.0 18 N·m (1.8 kgf·m, 13 lb·ft) Muffler nut M8 ×...
  • Page 153 TIGHTENING TORQUES Item Thread size Tightening torque Fuel pump bracket bolt M6 × 1.0 8 N·m (0.8 kgf·m, 5.9 lb·ft) Carburetor assembly bolt (EH63K/ M8 × 1.25 18 N·m (1.8 kgf·m, 13 lb·ft) EH64A/EH64K/EH65A/EH65B) Carburetor assembly nut (EH72A/ M6 × 1.0 8 N·m (0.8 kgf·m, 5.9 lb·ft) EH72B/EH72K) Throttle valve screw (EH63K/...

  • Page 154: Tightening Torques

    GENERAL TORQUE SPECIFICATIONS GENERAL TORQUE SPECIFICATIONS This chart specifies torque for standard fasteners with standard I.S.O. pitch threads. Torque specifi- cations for special components or assemblies are included in the applicable sections of this book. To avoid warpage, tighten multi fastener assemblies in a crisscross fashion, in progressive stages, until full torque is reached.

  • Page 155: Lubrication Points And Type Of Lubricants

    LUBRICATION POINTS AND TYPE OF LUBRICANTS LUBRICATION POINTS AND TYPE OF LUBRICANTS Part name Type of lubricant Oil seal lip Governor fork oil seal lip Bearing Connecting rod big end Crank pin Crankshaft journal Connecting rod cap bolt Piston pin Piston Crankshaft gear teeth Valve stem...

  • Page 156: Wire Routing Diagram

    WIRE ROUTING DIAGRAM WIRE ROUTING DIAGRAM FUEL PUMP AND FUEL HOSE (EH63K) 1. Oil pressure switch 3. Fuel hose 2. Spark plug cap 4. Fuel pump A. Point the spark plug cap in the direction shown in the illustration. B. Install the grommet all the way to the back of the fan case groove. 7-12...

  • Page 157: Fuel Pump And Fuel Hose (Eh64A)

    WIRE ROUTING DIAGRAM FUEL PUMP AND FUEL HOSE (EH64A) 1. Oil pressure switch 3. Fuel hose 2. Spark plug cap 4. Fuel pump A. Point the spark plug cap in the direction shown in the illustration. B. Install the grommet all the way to the back of the fan case groove. 7-13...

  • Page 158: Fuel Pump And Fuel Hose (Eh64K, Except For Kor)

    WIRE ROUTING DIAGRAM FUEL PUMP AND FUEL HOSE (EH64K, EXCEPT FOR KOR) 1. Oil pressure switch 3. Fuel hose 2. Spark plug cap 4. Fuel pump A. Point the spark plug cap in the direction shown in the illustration. B. Install the grommet all the way to the back of the fan case groove. 7-14...

  • Page 159: Fuel Pump And Fuel Hose (Eh64K, For Kor)

    WIRE ROUTING DIAGRAM FUEL PUMP AND FUEL HOSE (EH64K, FOR KOR) 1. Oil pressure switch 3. Fuel hose 2. Spark plug cap 4. Fuel pump A. Point the spark plug cap in the direction shown in the illustration. B. Install the grommet all the way to the back of the fan case groove. 7-15...

  • Page 160: Fuel Pump And Fuel Hose (Eh65A)

    WIRE ROUTING DIAGRAM FUEL PUMP AND FUEL HOSE (EH65A) 1. Oil pressure switch 5. Spark plug cap 2. Wire harness assembly 6. Fuel hose 3. Relay 7. Fuel pump 4. Clamp A. Clamp all wire leads after winding 1.5 or more turns. B.

  • Page 161: Fuel Pump And Fuel Hose (Eh65B)

    WIRE ROUTING DIAGRAM FUEL PUMP AND FUEL HOSE (EH65B) 1. Oil pressure switch 3. Fuel hose 2. Spark plug cap 4. Fuel pump A. Point the spark plug cap in the direction shown in the illustration. B. Install the grommet all the way to the back of the fan case groove. 7-17...

  • Page 162: Fuel Pump And Fuel Hose (Eh72A)

    WIRE ROUTING DIAGRAM FUEL PUMP AND FUEL HOSE (EH72A) 1. Oil pressure switch 4. Spark plug cap 2. Wire harness assembly 5. Fuel hose 3. Relay 6. Fuel pump A. Point the spark plug cap in the direction shown in the illustration. B.

  • Page 163: Fuel Pump And Fuel Hose (Eh72B, For Sea/Eh72K, For Chn)

    WIRE ROUTING DIAGRAM FUEL PUMP AND FUEL HOSE (EH72B, FOR SEA/EH72K, FOR CHN) 1. Oil pressure switch 3. Fuel hose 2. Spark plug cap 4. Fuel pump A. Point the spark plug cap in the direction shown in the illustration. B.

  • Page 164: Fuel Pump And Fuel Hose (Eh72K, Except For Chn)

    WIRE ROUTING DIAGRAM FUEL PUMP AND FUEL HOSE (EH72K, EXCEPT FOR CHN) 1. Oil pressure switch 3. Fuel hose 2. Spark plug cap 4. Fuel pump A. Point the spark plug cap in the direction shown in the illustration. B. Install the grommet all the way to the back of the fan case groove. 7-20...

  • Page 165: Air Filter, Carburetor And Fuel Hose (Eh63K/Eh64A/Eh64K, Except For Kor)

    WIRE ROUTING DIAGRAM AIR FILTER, CARBURETOR AND FUEL HOSE (EH63K/EH64A/EH64K, EXCEPT FOR KOR) 1. Carburetor 3. Clamp 2. Air filter element A. Insert the hose until it hits. 7-21...

  • Page 166: Air Filter, Carburetor And Fuel Hose (Eh64K, For Kor/Eh65A/Eh65B)

    WIRE ROUTING DIAGRAM AIR FILTER, CARBURETOR AND FUEL HOSE (EH64K, FOR KOR/EH65A/EH65B) 1. Carburetor 3. Clamp 2. Air filter element A. Insert the hose until it hits. 7-22...

  • Page 167: Air Filter, Carburetor And Fuel Hose (Eh72A/Eh72B/Eh72K)

    WIRE ROUTING DIAGRAM AIR FILTER, CARBURETOR AND FUEL HOSE (EH72A/EH72B/EH72K) 1. Carburetor 3. Clamp 2. Air filter element A. Insert the hose until it hits. 7-23...

  • Page 168: Carburetor And Intake Manifold (Eh64A/Eh64K, Except For Kor)

    WIRE ROUTING DIAGRAM CARBURETOR AND INTAKE MANIFOLD (EH64A/EH64K, EXCEPT FOR KOR) 1. Fuel pump 4. Breather hose 2. Fuel hose 5. Carburetor breather hose 3. Carburetor 6. Intake manifold A. Insert the breather hose to the base. B. Insert the carburetor breather hose to the base of the carburetor pipe. C.

  • Page 169: Carburetor And Intake Manifold (Eh64K, For Kor/Eh65A/Eh65B)

    WIRE ROUTING DIAGRAM CARBURETOR AND INTAKE MANIFOLD (EH64K, FOR KOR/EH65A/EH65B) 1. Fuel pump 4. Breather hose 2. Fuel hose 5. Carburetor breather hose 3. Carburetor 6. Intake manifold A. Insert the breather hose to the base. B. Insert the carburetor breather hose to the base of the carburetor pipe. C.

  • Page 170: Carburetor And Intake Manifold (Eh72A/Eh72B/Eh72K)

    WIRE ROUTING DIAGRAM CARBURETOR AND INTAKE MANIFOLD (EH72A/EH72B/EH72K) 1. Fuel pump 4. Intake manifold 2. Fuel hose 5. Carburetor breather hose 3. Breather hose 6. Clamp A. Insert the carburetor breather hose to the base of the carburetor pipe. B. Insert the breather hose to the base. C.

  • Page 171: Tci Unit (Eh63K)

    WIRE ROUTING DIAGRAM TCI UNIT (EH63K) 1. Terminal 4. Starter motor 2. Plastic locking tie 5. Flywheel 3. TCI unit #1 6. TCI unit #2 A. For the terminal, install the spark plug cap after caulking to the high tension cord. B.

  • Page 172: Tci Unit (Eh64A)

    WIRE ROUTING DIAGRAM TCI UNIT (EH64A) 1. Terminal 4. Starter motor 2. Plastic locking tie 5. Flywheel 3. TCI unit #1 6. TCI unit #2 A. For the terminal, install the spark plug cap after caulking to the high tension cord. B.

  • Page 173: Tci Unit (Eh64K, Except For Kor)

    WIRE ROUTING DIAGRAM TCI UNIT (EH64K, EXCEPT FOR KOR) 1. Plastic locking tie 4. Starter motor 2. Terminal 5. Flywheel 3. TCI unit #1 6. TCI unit #2 A. Position the lock portion on the lower side of the intake manifold. Cut the extra portion plastic locking tie so that projection is 0 mm (0 in).

  • Page 174: Tci Unit (Eh64K, For Kor)

    WIRE ROUTING DIAGRAM TCI UNIT (EH64K, FOR KOR) 1. Terminal 4. Starter motor 2. Plastic locking tie 5. Flywheel 3. TCI unit #1 6. TCI unit #2 A. For the terminal, install the spark plug cap after caulking to the high tension cord. B.

  • Page 175: Tci Unit (Eh65A)

    WIRE ROUTING DIAGRAM TCI UNIT (EH65A) 1. Terminal 4. Starter motor 2. Plastic locking tie 5. Flywheel 3. TCI unit #1 6. TCI unit #2 A. For the terminal, install the spark plug cap after caulking to the high tension cord. B.

  • Page 176: Tci Unit (Eh65B)

    WIRE ROUTING DIAGRAM TCI UNIT (EH65B) 1. Terminal 4. Starter motor 2. Plastic locking tie 5. Flywheel 3. TCI unit #1 6. TCI unit #2 A. For the terminal, install the spark plug cap after caulking to the high tension cord. B.

  • Page 177: Tci Unit (Eh72A)

    WIRE ROUTING DIAGRAM TCI UNIT (EH72A) 1. Terminal 4. Starter motor 2. Plastic locking tie 5. Flywheel 3. TCI unit #1 6. TCI unit #2 A. For the terminal, install the spark plug cap after caulking to the high tension cord. B.

  • Page 178: Tci Unit (Eh72B, For Sea/Eh72K, For Chn)

    WIRE ROUTING DIAGRAM TCI UNIT (EH72B, FOR SEA/EH72K, FOR CHN) 1. Terminal 4. Starter motor 2. Plastic locking tie 5. Flywheel 3. TCI unit #1 6. TCI unit #2 A. For the terminal, install the spark plug cap after caulking to the high tension cord. B.

  • Page 179: Tci Unit (Eh72K, Except For Chn)

    WIRE ROUTING DIAGRAM TCI UNIT (EH72K, EXCEPT FOR CHN) 1. Terminal 4. Starter motor 2. Plastic locking tie 5. Flywheel 3. TCI unit #1 6. TCI unit #2 A. For the terminal, install the spark plug cap after caulking to the high tension cord. B.

  • Page 180: Rectifier/Regulator And Starter Motor (Eh63K)

    WIRE ROUTING DIAGRAM RECTIFIER/REGULATOR AND STARTER MOTOR (EH63K) 1. Spark plug cap 5. Clamp 2 2. Rectifier/regulator 6. TCI unit #1 3. Starter motor 7. Clamp 1 4. Flywheel A. Point the spark plug cap in the direction shown in the illustration. B.

  • Page 181: Rectifier/Regulator And Starter Motor (Eh64A)

    WIRE ROUTING DIAGRAM RECTIFIER/REGULATOR AND STARTER MOTOR (EH64A) 1. Spark plug cap 4. Starter motor 2. Rectifier/regulator 5. Flywheel 3. Connector lead (Red) 6. TCI unit #1 A. Point the spark plug cap in the direction shown in the illustration. B.

  • Page 182: Rectifier/Regulator And Starter Motor (Eh64K, Except For Kor)

    WIRE ROUTING DIAGRAM RECTIFIER/REGULATOR AND STARTER MOTOR (EH64K, EXCEPT FOR KOR) 1. Spark plug cap 4. Flywheel 2. Rectifier/regulator 5. TCI unit #1 3. Starter motor A. Point the spark plug cap in the direction shown in the illustration. B. Install the grommet all the way to the back of the fan case groove. 7-38...

  • Page 183: Rectifier/Regulator And Starter Motor (Eh64K, For Kor)

    WIRE ROUTING DIAGRAM RECTIFIER/REGULATOR AND STARTER MOTOR (EH64K, FOR KOR) 1. Spark plug cap 4. Flywheel 2. Rectifier/regulator 5. Clamp 3. Starter motor 6. TCI unit #1 A. Point the spark plug cap in the direction shown in the illustration. B.

  • Page 184: Rectifier/Regulator And Starter Motor (Eh65A)

    WIRE ROUTING DIAGRAM RECTIFIER/REGULATOR AND STARTER MOTOR (EH65A) 1. Spark plug cap 4. Flywheel 2. Rectifier/regulator 5. Clamp 3. Starter motor 6. TCI unit #1 A. Point the spark plug cap in the direction shown in the illustration. B. Bundle 1.5 or more volumes other than the wire of the carburetor. C.

  • Page 185: Rectifier/Regulator And Starter Motor (Eh65B)

    WIRE ROUTING DIAGRAM RECTIFIER/REGULATOR AND STARTER MOTOR (EH65B) 1. Spark plug cap 4. Flywheel 2. Rectifier/regulator 5. TCI unit #1 3. Starter motor A. Point the spark plug cap in the direction shown in the illustration. B. Install the grommet all the way to the back of the fan case groove. 7-41...

  • Page 186: Rectifier/Regulator And Starter Motor (Eh72A)

    WIRE ROUTING DIAGRAM RECTIFIER/REGULATOR AND STARTER MOTOR (EH72A) 1. Spark plug cap 4. Flywheel 2. Rectifier/regulator 5. Clamp 3. Starter motor 6. TCI unit #1 A. Point the spark plug cap in the direction shown in the illustration. B. Bundle 1.5 or more volumes other than the wire of the carburetor. C.

  • Page 187: Rectifier/Regulator And Starter Motor (Eh72B, For Sea/Eh72K, For Chn)

    WIRE ROUTING DIAGRAM RECTIFIER/REGULATOR AND STARTER MOTOR (EH72B, FOR SEA/EH72K, FOR CHN) 1. Spark plug cap 4. Flywheel 2. Rectifier/regulator 5. TCI unit #1 3. Starter motor A. Point the spark plug cap in the direction shown in the illustration. B.

  • Page 188: Rectifier/Regulator And Starter Motor (Eh72K, Except For Chn)

    WIRE ROUTING DIAGRAM RECTIFIER/REGULATOR AND STARTER MOTOR (EH72K, EXCEPT FOR CHN) 1. Spark plug cap 4. Flywheel 2. Rectifier/regulator 5. Clamp 3. Starter motor 6. TCI unit #1 A. Point the spark plug cap in the direction shown in the illustration. B.
  • Page 189 WIRE ROUTING DIAGRAM MEMO 7-45...
  • Page 190 APPENDIX CIRCUIT DIAGRAM...
  • Page 191 1. Carburetor 8. Spark plug 2. Oil pressure switch 9. TCI unit #1 3. Oil warning light (option) 10.Rectifier/regulator 4. Engine switch (option) 11.Stator coil assembly 5. Battery (12 V, option) 12.TCI unit #2 6. Tachometer/hour meter (option) 13.Starter relay 7.
  • Page 192 MEMO...
  • Page 194 2019.03×1 !

This manual is also suitable for:

Eh64, eh65Eh72

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