Installing The Piston And Cylinder - Yamaha YXR70FX Service Manual

CYLINDER AND PISTON
4. Calculate:
• piston-pin-to-piston-pin-bore clearance
Out of specification → Replace the piston
pin and piston as a set.
Piston-pin-to-piston-pin-bore clearance =
Piston pin bore diameter b –
Piston pin outside diameter a
Piston-pin-to-piston clearance
0.004 ~ 0.024 mm
(0.0002 ~ 0.0009 in)
<Limit>: 0.074 mm (0.0029 in)
EBS00252

INSTALLING THE PISTON AND CYLINDER

1. Install:
• top ring 1
• 2nd ring 2
• oil ring expander 3
• lower oil ring rail 4
• upper oil ring rail 5
TIP:
_
Be sure to install the piston rings so that the
manufacturer marks or numbers face up.
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ENG