Yamaha XV16AL, Service Manual

Page: 274 / 449

5 - 55
ENG
CYLINDERS AND PISTONS
2. Measure:
• piston-to-cylinder clearance
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a. Measure cylinder bore “C” with the cyl-
inder bore gauge.
NOTE:
Measure cylinder bore “C” by taking side-
to-side and front-to-back measurements of
the cylinder. Then, find the average of the
measurements.
b. If out of specification, replace the cylin-
der, and the piston and piston rings as a
set.
c. Measure piston skirt diameter “P” with
the micrometer.
a
5 mm (0.20 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 clear-
ance with the following formula.
Cylinder bore gauge
YU-03017
Cylinder bore “C”
95.000 ~ 95.010 mm
(3.7402 ~ 3.7406 in)
Maximum taper “T” 0.05 mm (0.0016 in)
Out of round “R” 0.05 mm (0.0016 in)
“C” = maximum of D
1
~ D
6
“T” = maximum of D
1
or D
2
– maximum of
D
5
or D
6
“R” = maximum of D
1
, D
3
or D
5
– minimum of D
2
, D
4
or D
6
Micrometer
YU-03009
Piston size “P”
Standard
94.960 ~ 94.975 mm
(3.7386 ~ 3.7392 in)
Piston-to-cylinder clearance =
Cylinder bore “C” –
Piston skirt diameter “P”
5