Piston Outer Diameter

Measure the piston outer diameter using a micrometer. Measure piston skirt diameter at 90 degrees to piston pin center axis, 42 mm (1.62 inch) from top of piston. It may be necessary periodically to use another piston (within the same grade size) that is either slightly larger or smaller to achieve the specified clearance.

Due to skirt coating, the piston size cannot be measured. Pistons are graded prior to skirt coating. Grade sizes with coating are:
- Grade 1: 90.187-90.212
- Grade 2: 90.200-90.225
- Grade 3: 90.213-90.238