Note: The markings may not be visible on used rings. Place removed rings in their cylinder numbering sequence and position on the piston. Install new pistons only with new rings.
The piston rings must be replaced in the following order. Disassemble the engine and remove the pistons. Using a spiral collet, remove the piston rings. The rings have worn in to the pistons, they should be folded with a tie to them. When installing, make sure that the "TOP" mark on the ring plane is facing the piston bottom (fig. 3.101).
1 - trapezoid; 2 - scraper; 3 - box-shaped
Check the values of the axial clearance in the groove and the clearance in the ring lock. The axial clearance of the compression rings should be 0.020-0.060 mm, the oil scraper ring - 0.015-0.060 mm. The clearance in the compression ring lock should be 0.20-0.40 mm, the oil scraper ring - 0.20-0.45 mm. Move the ring locks apart at an angle of 120° relative to each other, while the track joints should not be located above the piston pin bosses.