Yamaha YFM660RN, Руководство по обслуживанию

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ENG
CYLINDER AND PISTON
CHECKING THE PISTON RING
1.Measure:
●
Ring side clearance
Use a feeler gauge.
Out of specification
→
Replace the piston
and rings as a set.
NOTE:
Clean carbon from the piston ring grooves and
rings before measuring the side clearance.
Side clearance
Standard Limit
Top
ring
0.04 ~ 0.08 mm
(0.0016 ~ 0.0031 in)
0.13 mm
(0.0051 in)
2nd
ring
0.03 ~ 0.07 mm
(0.0012 ~ 0.0028 in)
0.13 mm
(0.0051 in)
2.Position:
●
Piston ring
(in cylinder)
NOTE:
Insert a ring into the cylinder and push it
approximately 50 mm (2.0 in) into the cylinder.
Push the ring with the piston crown so that the
ring will be at a right angle to the cylinder bore.
a
50 mm (2.0 in)
3.Measure:
●
Ring end gap
Out of specification
→
Replace.
NOTE:
You cannot measure the end gap on the
expander spacer of the oil control ring. If the oil
control ring rails show excessive gap, replace
all three rings.
End gap
Standard Limit
Top
ring
0.30 ~ 0.45 mm
(0.0118 ~ 0.0177 in)
0.70 mm
(0.0276 in)
2nd
ring
0.30 ~ 0.45 mm
(0.0118 ~ 0.0177 in)
0.80 mm
(0.0315 in)
Oil
ring
0.2 ~ 0.7 mm
(0.0079 ~ 0.0276 in)
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