Yamaha EXCITER, Service Manual

Page: 150 / 349

4-34
ENG
CYLINDER AND PISTON
f. If out of specification, replace the cylinder,
and replace the piston and piston rings as a
set.
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EAS00263
CHECKING THE PISTON RINGS
1. Measure:
9
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.
2. Install:
9
piston ring
(into the cylinder)
NOTE:
Level the piston ring into the cylinder with the
piston crown.
a
40 mm
Piston-to-cylinder clearance
0.0015 – 0.048 mm
(0.0006 – 0.0019 in)
<Limit>: 0.15 mm (0.0059)
Piston-to-cylinder clearance =
Cylinder bore “C” –
Piston skirt diameter “P”
Piston ring side clearance
Top ring
0.030 – 0.065 mm
(0.0012 – 0.0026 in)
<Limit>: 0.1 mm (0.0039 in)
2nd ring
0.020 – 0.055 mm
(0.0008 – 0.0022 in)
<Limit>: 0.1 mm (0.0039 in)
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