2. To remove the piston rings from the pistons, open the piston ring and insert two or three old feeler blades evenly around the circumference under the ring and slide the ring off the piston along them. Be careful not to scratch the piston with the ends of the ring. The rings are very brittle and can crack if unclenched too much. The piston ring lips are very sharp, so handle them very carefully to avoid cutting yourself. Keep each set of rings with the pistons to reinstall them.
3. Clean all carbon deposits from the top of the piston.
4. Remove carbon deposits from the piston ring grooves in the piston using the old piston ring.
5. After removing deposits, clean the piston with connecting rod with a suitable solvent and wipe dry.
6. Carefully inspect each piston for cracks around the skirt and piston pin holes.
7. Check for wear on the piston skirt, hole in the piston head, and burns on the top of the piston.
8. Pitting marks on the piston indicate that coolant has entered the combustion chamber. It is necessary to find the cause of the coolant entering the combustion chamber and eliminate it.
9. Measure the piston diameter.
10. Determine the piston clearance in the cylinder, for which subtract the piston diameter from the cylinder diameter and divide by two.
11. Check the piston ring clearance in the piston groove.