Crankcase
7-48
Checking the piston diameter
1. Measure:
• Piston outside diameter “a” (at
the speci-
fied measuring point “b”)
Below specification Replace.
Checking the cylinder bore
1. Measure:
• Cylinder
bore (D1–D6) (at measuring
points “a”, “b”, and “c”, and in directions “d”
(D1, D3, D5) and “e” (D2, D4, D6))
Above specification
Replace the cylin-
der block.
Checking the piston clearance
1. Measure:
• Piston diameter
See “Checking the piston diameter” (7-48).
• Cylinder bo
re
See “Checking the cylinder bore” (7-48).
2. Calculate:
• Piston clearance
Out of specification Repla
ce the piston
or cylinder block.
Piston
Diameter
80.950–80.962 mm (3.1870–
3.1875 in)
Limit
80.910 mm (3.1854 in)
1st oversize diameter
81.200–81.212 mm (3.1968–
3.1973 in)
Measuring point
9.5 mm (0.37 in)
above the bottom of the piston skirt
a
b
a. 5.0 mm (0.20 in)
b. 35.0 mm (1.38 in)
c. 94.0 mm (3.70 in)
d. Parallel to the crankshaft
e. At a right angle to the crankshaft
Cylinder
Bore
81.000–81.012 mm (3.1890–
3.1894 in)
Limit
81.060 mm (3.1913 in)
Piston clearance = Maximum cylinder
bore – Piston outside diameter
Piston clearance
0.038–0.062 mm (0.0015–0.0024
in)
Limit
0.150 mm (0.0059 in)
a
b
c
d
e
D
1
D
2
D
3
D
4
D
5
D
6
To Next Page
