Checking The Piston Rings - Yamaha 2012 TMAX XP500A Service Manual

Bore = maximum of D
Taper limit = maximum of D
mum of D or D
5 6
Out of round limit = maximum of D
- minimum of D , D
2 4
b. If out of specification, replace the cylinder,
piston and piston rings as a set.
c. Measure piston skirt diameter "a" with the
micrometer.
b. 9.0 mm (0.35 in) from the bottom edge of
the piston
Piston
Diameter
67.975–67.990 mm (2.6762–
2.6768 in)
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.
• Piston-to-cylinder clearance =
Cylinder bore -
Piston skirt diameter
–D
1 2
or D - maxi-
1 2
, D or D
1 3
or D
6
CYLINDER AND PISTONS
Piston-to-cylinder clearance
Limit
5
f. If out of specification, replace the cylinder,
piston and piston rings as a set.
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EAS24430

CHECKING THE PISTON RINGS

1. Measure:
• Piston ring side clearance
Out of specification → Replace the piston
and piston rings as a set.
TIP
Before measuring the piston ring side clear-
ance, eliminate any carbon deposits from the
piston ring grooves and piston rings.
Piston ring
Top ring
Ring side clearance
Limit
2nd ring
Ring side clearance
Limit
2. Install:
• Piston ring
(into the cylinder)
TIP
Level the piston ring into the cylinder with the
piston crown.
5-31
0.010–0.035 mm
0.0014 in)
0.15 mm (0.0059 in)
0.030–0.065 mm
0.0026 in)
0.100 mm (0.0039 in)
0.020–0.055 mm
0.0022 in)
0.100 mm (0.0039 in)
(0.0004–
(0.0012–
(0.0008–