2. Most likely, the grooves for the upper rings will be worn out the most. After the grooves have been cleaned, install the top rings into their grooves and check the side clearances with feeler gauges.
3. Carefully inspect the pistons for wear and damage. Pay attention to whether there are small hairline cracks around the holes for the piston pins.
4. If any of the pistons are obviously worn, damaged or burned, the pistons must be replaced. A badly worn top ring groove on an otherwise in good condition piston can be bored out to accommodate a thicker ring. If necessary, this can be a ledge ring so as not to touch the protrusion at the top of the sleeve. New pistons must match the class of their liners (see previous section). Disconnection of pistons and connecting rods must be carried out by a specialist, because. The piston pin has an interference fit in the top end of the connecting rod.
5. If the engine has not jammed and does not have any serious damage, the connecting rods do not require special attention. It is enough to clean them and inspect for obvious defects. In the presence of damage or uneven wear of the pistons, sleeves or bearings, it is advisable to check the connecting rods for distortion. This work requires special tools and must be carried out by a specialist.
6. Before installing new rings on the pistons, it is necessary to measure their clearance in the lock. In principle, the gap should be adjusted at the factory, however, in case of doubt, you can insert the ring into the sleeve approximately at the middle of its height, check that it stands without distortions and measure the gap in the lock using feeler gauges. A gap in the range of 0.254-1.016 mm is considered acceptable.
7. When installing new pistons with new piston rings in new liners, the gaps in the ring lock can be measured at the top of the liners, because New sleeves have no taper.
8. Install the lower oil scraper ring on the piston first, and then the second compression ring. This ring has a special chamfer, so care must be taken that it is installed in the correct position. The mark on the top surface of the ring should face the piston crown. Next ring (top) can be installed in any position. The rings are installed in the reverse order of their removal. Be very careful as Compression rings are brittle and break easily.
