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:

- Use a boring gauge in order to measure the cylinder bore diameter at a point of 66mm (2.5 in) from the top of the cylinder bore.
- Use a micrometer or caliper in order to measure the piston 11.5 mm (0.45 in) from the bottom of the skirt at right angles to the piston pin.
- Subtract the piston diameter from the cylinder bore diameter in order to indicate piston-to-bore clearance.
- Compare the measurements to specifications.
- Mark the piston for installation to the proper cylinder.
- A used piston may be installed if clearance is within specifications.