4-33
ENG
CYLINDER AND PISTON
EAS00255
CHECKING THE CYLINDER AND
PISTON
1. Check:
9
piston surface
9
cylinder wall
Vertical scratches
→
Replace the cylinder,
and replace the piston and piston rings as a
set.
2. Measure:
9
piston-to-cylinder clearance
✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭
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.
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 a
micrometer.
a
5 mm 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.
Cylinder bore “C”
54.000 – 54.010 mm
(2.1260 – 2.1264 in)
Limit 54.100 mm (2.1299 in)
Taper limit “T” 0.05 mm (0.002 in)
Out-of-round “R” 0.05 mm (0.002 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
Piston size “P”
Standard
53.962 – 53.985 mm
(2.1245 – 2.1254 in)
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