50
Cylinder Trueness
1. Measure each cylinder in the three locations from front
to back and side to side for a total of six readings.
FC044
2. Trueness (out-of-roundness) is the difference between
the highest and lowest reading. Maximum trueness
(out-of-roundness) must not exceed specifications.
0725-586
Piston Skirt/Cylinder Clearance
1. Measure each cylinder front to back about 2.5 cm
(1 in.) from the bottom of each cylinder.
2. Measure the corresponding piston skirt diameter at a
point 1 cm (0.394 in.) above the piston skirt at a
right angle to the piston-pin bore. Subtract this mea-
surement from the measurement in step 1. The dif-
ference (clearance) must be within specifications.
AC091
Piston-Ring End Gap
1. Place each piston ring in the wear portion above the
exhaust port of its respective cylinder. Use the pis-
ton to position each ring squarely in each cylinder.
2. Using a feeler gauge, measure each piston-ring
end gap. Acceptable ring end gap must be within
specifications.
FC045
Piston Pin and Piston-Pin Bore
1. Measure the piston pin diameter at each end and in
the center. Acceptable piston pin measurement
must be within specifications. If any measurement
varies by more than 0.02 mm (0.001 in.), the pis-
ton pin and bearing must be replaced as a set.
IO012
2. Insert a snap gauge into each piston-pin bore; then
remove the gauge and measure it with a micrometer.
The diameter measurement must be within specifica-
tions. Take two measurements to ensure accuracy.
RS042
CYLINDER TRUENESS LIMIT (max)
mm
in.
0.010
0.004
