Checking The Piston Rings - Yamaha FJR1300R Service Manual

CONNECTING RODS AND PISTONS
5 - 94
c. Measure piston skirt diameter "P" with the
micrometer.
a 5 mm (0.20 in) from the bottom edge of the pis-
ton
Standard
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
0.020 ~ 0.045 mm
(0.0008 ~ 0.0018 in)
<Limit>: 0.012 mm (0.0005 in)
f. If out of specification, replace the cylinder,
and the piston and piston rings as a set.
L LLL L LLL L L LLL L L LLL L
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.
Piston ring side clearance
Top ring
0.03 ~ 0.07 mm
(0.0012 ~ 0.0028 in)
<Limit>: 0.12 mm (0.0047 in)
2nd ring
0.02 ~ 0.06 mm
(0.0008 ~ 0.0024 in)
<Limit>: 0.12 mm (0.0047 in)
ENG
Piston size "P"
78.965 ~ 78.980 mm
(3.1089 ~ 3.1094 in)
L LLL L L LLL L LLL