Piston Pin Bore Measurement Procedure

1. Piston pin bores and pins must be free of varnish or scuffing.
2. Use an outside micrometer to measure the piston pin in the piston contact areas.
3. Using an inside micrometer, measure the piston pin bore.
4. Subtract the measurement of the piston pin bore from the piston pin.
5. Compare the result with the engine mechanical specifications.
6. If the clearance is excessive, determine which piece is out of specification and replace as necessary.