Note. Spare pistons are supplied with piston rings and gudgeon pin.
Piston ring-piston groove coupling
The figure shows the axial clearance of the piston rings.
Upper piston ring wear limit: 0.15 mm/0.0059 in.
Second piston ring and scraper ring wear limit: 0.10 mm/0.0039 in.
Note. The punched word TOP must always be facing up in piston-piston ring couplings.
Piston ring-cylinder coupling
Insert the piston ring in the lowest part of the cylinder (where wear is at a minimum), making sure it is positioned "in square".
Measure the distance between the two ring ends:
- 1° and 2° piston ring wear limit: 1.0 mm/0.0039 in.
- scraper ring wear limit: 1.0 mm/0.0039 in.
Note. A higher play indicates excessive wear of the piston ring or cylinder, or a combination of the two.