ENG
5-12
2. Measure:
• piston-to-cylinder clearance
a. Measure cylinder bore “C” with the cylinder
bore gauge.
NOTE:
NOTE:
Measure cylinder bore “C” by taking side-to-
side and front-to-back measurements of the
cylinder. Then, find the average of the mea-
surements.
b. If out of specification, replace the cylinder,
and the piston and piston rings as a set.
c. Measure piston skirt diameter “P” with the
micrometer.
20.0 mm (0.79 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 clearance
with the following formula.
f. If out of specification, replace the cylinder,
and the piston and piston rings as a set.
Standard
47.500 ~ 47.514 mm
(1.8701 ~ 1.8706 in)
Wear limit
47.6 mm (1.8740 in)
Taper limit “T”
0.05 mm (0.0020 in)
Out of round “R”
0.05 mm (0.0020 in)
“C” = maximum of D
1
~ D
6
“T” =
maximum of D
1
or D
2
–
maxmum 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
47.457 ~ 47.472 mm (1.8684 ~ 1.8690 in)
Piston-to-cylinder clearance =
Cylinder bore “C” –
Piston skirt diameter “P”
Piston-to-cylinder clearance
0.040 ~ 0.045 mm
(0.0016 ~ 0.0018 in)
<Limit>: 0.10 mm (0.0039 in)
CYLINDER HEAD, CYLINDER AND PISTON
