Checking The Piston Rings - Yamaha MT-03 Service Manual

b. If out of specification, replace the cylinder
and the piston and piston rings as a set.
c. Measure piston skirt diameter "P" with the
micrometer.
a. 10 mm (0.39 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.
Piston-to-cylinder clearance =
Cylinder bore "C" -
Piston skirt diameter "P"
Piston-to-cylinder clearance
0.030-0.055 mm
(0.0012-0.0022 in)
<Limit>: 0.13 mm (0.0051 in)
f. If out of specification, replace the cylinder
and the piston and piston rings as a set.
CYLINDER AND PISTON
EAS00263

CHECKING THE PISTON RINGS

1. Measure:
• Piston ring side clearance
Out of specification
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.
Piston ring side clearance
Top ring
0.030-0.080 mm
(0.0012-0.0031 in)
<Limit>: 0.13 mm (0.0051 in)
2 nd ring
0.030-0.070 mm
(0.0012-0.0028 in)
<Limit>: 0.11 mm (0.0043 in)
2. Install:
• Piston ring
(into the cylinder)
NOTE:
Level the piston ring into the cylinder with the
piston crown.
a. 40 mm (1.57 in)
5-29
Replace the piston