Piston Rings
NOTE:
Compression rings differ in scraping edge design. From a cross sectional view, ring No. 1 has a barrel shaped scraping edge and ring No. 2 has a tapered edge.
- Measure piston ring side and end clearance for all pistons and replace rings as necessary. When replacing a ring without correcting the cylinder bore, check ring end gap at lower part of cylinder that is less worn. When replacing a ring, be sure to use one of the same size.
- Install rings on piston with end gaps staggered at 120° intervals, but make sure no ring gap is in line with thrust face of pin bore. Also be sure the manufacturer's marks are facing upward when rings are installed.
CAUTION:
Install oil ring first without using a ring expander. Spacer expander gap should be installed more than 45° from side rail gaps, and rails should turn smoothly when installed.
PISTON RING SIZES
| Ring Size | Size Mark |
|---|---|
| Standard | No Mark |
| .25 mm Oversize | 25 |
| .50 mm Oversize | 50 |
| .75 mm Oversize | 75 |
| 1.00 mm Oversize | 100 |