Piston Rings
End Gap1. Using a piston, push a new ring into the cylinder bore 15 - 20 mm (0.6 - 0.8 inch) from the bottom.
2. Measure the piston ring end-gap with a feeler gauge:
- If the gap is too small, check to see if you have the proper rings for your engine.
- If the gap is too large, recheck the cylinder bore diameter against the wear limits. If the bore is over the service limit, the cylinder block must be rebored.
Replacement
1. Using a ring expander, remove the old piston rings.
2. Clean all the ring grooves thoroughly.
NOTE:
- Use a squared-off broken ring or ring groove cleaner with a blade to fit the piston grooves. File down the blade if necessary.
- Top ring groove is 1.5 mm (0.06 inch) wide, the second ring groove is 1.2 mm (0.05 inch) wide, and the oil ring groove is 2.8 mm (0.11 inch) wide.
CAUTION: Do not use a wire brush to clean the ring grooves, or cut ring grooves deeper with the cleaning tool.
NOTE: If the piston is to be separated from the connecting rod, do not install new rings yet.
3. Install new rings in the proper sequence and position.
NOTE: Do not reuse old piston rings.
Ring-to-Groove Clearance
After installing a new set of rings, measure the ring- to groove clearance:
Alignment
1. Install the rings.
NOTE: The manufacturing marks must be facing upward.
2. Rotate the rings in their grooves to make sure they do not bind.
3. Position the ring end gaps.