Piston Ring Replacement

1. Using a piston, push a new ring (A) into the cylinder bore 15-20 mm (0.6 from the bottom.
2. Measure the piston ring end-gap (B) 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.

Piston Ring End-Gap:
Top Ring
Standard (New): 0.20-0.35 (0.008-0.014 inch)
Service Limit: 0.60 mm (0.024 inch)
Second Ring
Standard (New): 0.40-0.55 mm (0.016-0.022 inch)
Service Limit: 0.70 mm 90.028 inch)
Oil Ring
Standard (New): 0.20-0.70 mm (0.008-0.028 inch)
Service Limit: 0.80 mm (0.31 inch)





3. Using a ring expander (A), remove the old piston rings (B).
4. Clean all the ring grooves thoroughly with 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 and second ring grooves are 1.2 mm (0.05 inch) wide, and the oil ring groove is 2.8 mm (0.11 in) wide. Do not use a wire brush to clean the ring grooves, or cut the 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.





5. Install the rings as shown. The top ring (A) has a 1B and the second ring (B) is marked 2B. The manufacturing marks (C) must be facing upward.





6. After installing a new set of rings, measure the ring-to-groove clearance:

Top Ring Clearance
Standard (New): 0.035-0.060 mm (0.0014-0.0024 inch)
Service Limit: 0.13 mm (0.005 inch)
Second Ring Clearance
Standard (New): 0.030-0.055 mm (0.0012-0.0022 inch)
Service Limit: 0.13 mm (0.005 inch)

7. Rotate the rings in their grooves to make sure they do not bind.





8. Position the ring end gaps as shown: