Yamaha XJR1300(L) 99, Service Manual

Page: 140 / 338

4-28
ENG
CYLINDERS AND PISTONS
NOTE:
a. Measure cylinder bore “C” with the cylinder
bore gauge.
1 20 mm from the top of the cylinder
Measure cylinder bore “C” by taking side-to-
side and front-to-back measurements of the cyl-
inder. Then, find the average of the measure-
ments.
Cylinder bore gauge
Standard 79.00 79.01 mm
Wear limit 79.1 mm
Cylinder bore “C” “C” = X + Y / 2
b. If out of specification, replace the cylinder,
and replace the piston and piston rings as a
set.
c. Measure piston skirt diameter “P” with the
micrometer.
a 2.0 mm from the bottom edge of the piston.
Piston size “P”
Standard 78.970 78.985
mm
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
0.015 0.040 mm
<Limit> : 0.15 mm
f. If out of specification, replace the cylinder,
and replace the piston and piston rings as a
set.