Yamaha tmax XP500A, Service Manual

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5 - 33
ENG
CYLINDER AND PISTON
c. Measure piston skirt diameter “P” with the
micrometer.
a
9.0 mm (0.35 in) from the bottom edge of the
piston
d. If out of specification, replace the piston and
piston rings as a set.
e. Calculate the piston-to-cylinder clearance
with the following formula.
f. If out of specification, rebore or replace the
cylinder, and replace the piston and piston
rings as a set.
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EAS00263
CHECKING THE PISTON RINGS
1. Measure:
• piston ring side clearance
Out of specification
→
Replace the piston
and piston rings as a set.
NOTE:
Before measuring the piston ring side clear-
ance, eliminate any carbon deposits from the
piston ring grooves and piston rings.
Micrometers (50 ~ 75 mm)
90890-03008, YU-03008
Piston size “P”
Standard
65.965 ~ 65.980 mm
(2.5970 ~ 2.5976 in)
Piston-to-cylinder clearance =
Cylinder bore “C” –
Piston skirt diameter “P”
Piston-to-cylinder clearance
0.020 ~ 0.045 mm
(0.0008 ~ 0.0018 in)
<Limit>: 0.15 mm (0.0059 in)
Piston ring side clearance
Top ring
0.030 ~ 0.065 mm
(0.0012 ~ 0.0026 in)
<Limit>: 0.10 mm (0.0039 in)
2nd ring
0.020 ~ 0.055 mm
(0.0008 ~ 0.0022 in)
<Limit>: 0.10 mm (0.0039 in)