Yamaha WR450F Owner's Service Manual page 262

2. Install:
• Piston "1"
• Piston pin "2"
• Piston pin clips "3"
TIP
• Apply molybdenum disulfide oil to the piston
pin.
• Install the piston with the F mark "a" on it
pointing to its intake (front) side.
• Before installing the piston pin clip, cover the
crankcase opening with a cloth to prevent the
clip from falling into the crankcase.
1
a
2
3. Lubricate:
• Piston
• Piston rings
• Cylinder
4. Offset:
• Piston ring end gap
a
15°
d
15°
15°
e
a. Top ring
b. 2nd ring
c. Upper oil ring rail
d. Oil ring expander
e. Lower oil ring rail
New
3
3
c
15°
15°
b
CYLINDER AND PISTON
5. Install:
• Cylinder gasket
• Dowel pin
• Cylinder
Cylinder bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
TIP
• While compressing the piston rings with one
hand, install the cylinder with the other hand.
• Pass the timing chain and timing chain guide
(exhaust side) through the timing chain cavity.
6-35
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