1. If the pistons are being reinstalled on the engine, carefully remove the piston rings by spreading each ring just enough to remove through the web between the grooves on the piston body.
2. To prevent the rings from falling into the groove above, it is recommended to insert two or three narrow strips of sheet metal (old stylus plates) under the ring at equal distances from each other, and then twist the ring off the piston.
3. Clean the grooves and rings from carbon deposits so as not to scratch the aluminum surfaces of the piston.
4. If new rings are installed, the top compression ring should be stepped to avoid it hitting the «wear ring», which formed in the upper part of the cylinder bore.
5. Before the final installation of the rings on the pistons, measure the gaps in the locks of the rings. These clearances must comply with the technical requirements.
6. Check the ring backlash for specification with a feeler gauge. If the clearance is too large, replace the piston as its groove is worn in height.
7. Install the rings and rotate their locks evenly around the circumference of the piston (at 120°).