Service manual
Table Of Contents
- Inroduction
- Yamaha Motor Corporation, USA YZ/WR Motorcycle Limited Warranty
- How to use this Manual
- Index
- Contents
- Chapter 1 General Information
- Chapter 2 Specifications
- Chapter 3 Regular Inspection and Adjustments
- Chapter 4 Engine
- Seat, Fuel Tank and Side Covers
- Exhaust Pipe and Silencer
- Radiator
- Carburetor and Reed Valve
- Cylinder Head, Cylinder and Piston
- Clutch and Primary Driven Gear
- Kick Axle, Shift Shaft and Primary Drive Gear
- YPVS Govenor
- Water Pump
- CDI Magneto
- Engine Removal
- Crankcase and Crankshaft
- Transmission, Shift Cam and Shift Fork
- Chapter 5 Chassis
- Chapter 6 Electrical
- Chapter 7 Tuning
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4-27
ENG
CYLINDER HEAD, CYLINDER AND PISTON
EC475280
Piston ring and piston
1. Install:
9
Piston ring 1
NOTE:
9
Take care not to scratch the piston or damage
the piston ring.
9
Align the piston ring gap with the pin 2.
9
After installing the piston ring, check the
smooth movement of it.
2. Install:
9
Gasket (cylinder) 1
9
Small end bearing 2
9
Dowel pin 3
NOTE:
9
Apply the engine oil onto the bearing (crank-
shaft and connecting rod) and connecting rod
big end washers.
9
Install the gasket with the seal print side toward
the crankcase.
3. Install:
9
Piston 1
9
Piston pin 2
9
Piston pin clip 3
NOTE:
9
The arrow a on the piston dome must point to
exhaust side.
9
Before installing the piston pin clip, cover the
crankcase with a clean rag to prevent the pis-
ton pin clip from falling into the crankcase cavi-
ty.
cC
9When installing the piston pin clip, use
the hand so that it may not be distorted.
9Do not allow the clip open ends to meet
the piston pin slot b.
1C3-28199-10 116 04.5.17, 9:22:28 PM