Yamaha XT1200Z(Z) 2010, Service Manual

Page: 334 / 616

CYLINDER AND PISTONS
5-39
b. If out of specification, replace the cylinder,
and replace the piston and piston rings as a
set.
c. Measure piston skirt diameter D “a” with the
micrometer.
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, replace the cylinder,
and replace the piston and piston rings as a
set.
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EAS24430
CHECKING THE PISTON RINGS
The following procedure applies to both of 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 clearance,
eliminate any carbon deposits from the piston
ring grooves and piston rings.
2. Install:
• Piston ring
(into the cylinder)
TIP
Level the piston ring into the cylinder with the
piston crown.
Diameter D
97.965–97.980 mm (3.8569–
3.8575 in)
b. 8.0 mm (0.31 in) from the bottom edge of the
piston
• Piston-to-cylinder clearance =
Cylinder bore “C” -
Piston skirt diameter “D”
Piston-to-cylinder clearance
0.020–0.045 mm (0.0008–0.0018
in)
Limit
0.15 mm (0.0059 in)
Piston ring
Top ring
Ring side clearance
0.030–0.070 mm (0.0012–
0.0028 in)
Limit
0.120 mm (0.0047 in)
2nd ring
Ring side clearance
0.020–0.060 mm (0.0008–
0.0024 in)
Limit
0.120 mm (0.0047 in)