Yamaha MA190, Service Manual

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I. PARTS DESCRIPTION
1-1 Part description .....................................1
1-1-1 Feature ...........................................1
1-1-2 Model & serial number ...................1
1-2 Specification ..........................................2
1-3 Service limit ...........................................3
II. DIMENSION AND TORQUE
2-1 Engine dimension .................................4
2-1-1 Appearance dimension ...................4
2-1-2 Installation hole position .................5
2-1-3 P.T.O. dimension figure ...................5
2-2 Torque value ...........................................8
2-3 Standard torque value ..........................9
2-4 Important bolt torque value .................9
III. MAINTENANCE
3-1 Maintenance schedule .......................10
3-2 Change oil ............................................11
3-3 AIR CLEANER ......................................13
3-4 Fuel parts .............................................14
3-4-1 Strainer clean ...............................14
3-4-2 Fuel check ....................................14
3-5 Spark Plug Service .............................16
3-6 Valve clearance adjustment ...............17
3-7 Governor adjusting .............................19
IV. DISASSEMBLING AND
SERVICING
4-1 Troubleshooting ...................................20
4-1-1 Starting difficult .............................20
4-1-2 Power lack ....................................22
4-1-3 Unstable speed ............................23
4-1-4 Unable to ignite ............................23
4-1-5 Engine overheat ...........................24
4-1-6 Abnormal sound ...........................24
4-1-7 Exhaust gas color abnormal.........25
4-2 Preparation of servicing .....................25
4-2-1 Safety precautions ........................25
4-2-2 Special tools ................................26
4-3 Engine ..................................................27
4-3-1 Recoil starter/housing ..................27
4-3-2 Fuel tank .......................................28
4-3-3 Ignition coil/flywheel .....................29
4-3-4 Muffler ..........................................32
4-3-5 Air cleaner ....................................33
4-3-6 Carburetor ....................................34
4-3-7 Throttle control ..............................37
4-3-8 Timing chain .................................38
4-3-9 Cylinder head/valve train ..............43
4-3-10 Crankcase cover/
governor gear .........................................49
4-3-11 Crankshaft/piston/crankcase ......50
4-4 Electric diagram ..................................58