Piston Selection

1. Measure the piston-to-cylinder bore clearance to determine the suitability of a used piston.
2. Measure the piston-to-cylinder bore clearance as follows:
a. Use a boring gage in order to measure the cylinder bore diameter at a point of 66 mm (2.5 inches) from the top of the cylinder bore.
b. Use a micrometer or caliper in order to measure the piston 11.5 mm (0.45 inches) from the bottom of the skirt at right angles to the piston pin.
c. Subtract the piston diameter from the cylinder bore diameter in order to determine piston-to-bore clearance.
d. Compare the measurements to specifications.
e. Mark the piston for installation to the proper cylinder.
f. A used piston may be installed if clearance is within specifications.