Checking The Cylinder And Piston - Yamaha Sirius T110LSE Service Manual

CYLINDER AND PISTON
EAS00255
CHECKING THE CYLINDER AND
PISTON
1. Check:
9piston wall
9cylinder wall
Vertical scratches → Rebore or replace the
cylinder, and replace the piston and piston
rings as a set.
2. Measure:
9piston-to-cylinder clearance
MMMMMMMMMMMMMMMMMMMMMMMM
a. Measure cylinder bore "C" with the cylinder
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.
Cylinder bore "C"
Limit
Taper limit "T"
Out-of-round "R"
"C" = maximum of D
"T" = maximum of D
D or D
5 6
"R" = maximum of D
of D , D or D
2 4
b. If out of specification, rebore or replace the
cylinder, and replace the piston and piston
rings as a set.
c. Measure piston skirt diameter "P" with a
micrometer.
a 5 mm from the bottom edge of the piston
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.
4-33
ENG
51.000 – 51.015 mm
(2.0079 – 2.0085 in)
51.1 mm (2.03 in)
0.05 mm (0.002 in)
0.05 mm (0.002 in)
– D
1 2
or D – maximum of
1 2
, D or D – minimum
1 3 5
6
Piston size "P"
50.977 – 50.992 mm
(2.0070 – 2.0076 in)