Yamaha YFM400FAR, Service Manual

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ENG
CYLINDER AND PISTON
●
If out of specification, replace the piston.
*****************************************************
Piston pin-to-piston clearance:
0.004 ~ 0.024 mm
(0.00016 ~ 0.00094 in)
<Limit>: 0.074 mm (0.0029 in)
INSTALLING THE PISTON
1.Install:
●
Piston rings
(onto the piston)
NOTE:
●
Be sure to install the piston rings so that the
manufacturer’s marks or numbers are
located on the upper side of the rings.
●
Lubricate the piston and piston rings liberally
with engine oil.
2.Position:
●
Top ring
●
2nd ring
●
Oil ring
Offset the piston ring end gaps as shown.
a
Top ring end
b
Oil ring end (upper)
c
Oil ring end (lower)
d
2nd ring end
3.Install:
●
Piston
1
●
Piston pin
2
●
Piston pin clips
3
NOTE:
●
Apply engine oil onto the piston pin, piston
ring and piston.
●
Be sure that the arrow mark
a
on the piston
points to the exhaust side of the engine.
●
Before installing the piston pin clips, cover
the crankcase with a clean rag to prevent the
piston pin clips from falling into the
crankcase.
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