Piston Ring Replacement

Piston Ring Replacement

1.Remove the piston from the cylinder block.

2.Using a ring expander (A), remove the old piston rings (B).


3.Clean all ring grooves thoroughly with a squared-off broken ring or ring groove cleaner with a blade to fit the piston grooves.
The top ring groove is 1.0 mm (0.04 in.) wide. The second ring groove is 1.2 mm (0.05 in.) wide. The oil ring groove is 2.0 mm (0.08 in.) wide.
File down a blade if necessary.
Do not use a wire brush to clean the ring grooves, or cut the ring grooves deeper with the cleaning tools.

NOTE: If the piston is to be separated from the connecting rod, do not install new rings yet.

4.Using a piston, push a new ring (A) into the cylinder bore 15-20 mm (0.6-0.8 in.) from the bottom.


5.Measure the piston ring end-gap (B) with a feeler gauge:

Piston Ring End-Gap:
Top Ring 
Standard (New): 0.15-0.30 mm
(0.006-0.012 in.)
Service Limit: 0.60 mm (0.024 in.) 

Second Ring 
Standard (New): 0.35-0.50 mm
(0.014-0.020 in.)
Service Limit: 0.65 mm (0.026 in.) 

Oil Ring 
Standard (New): 0.20-0.70 mm
(0.008-0.028 in.)
Service Limit: 0.80 mm (0.031 in.) 

6.Install the top ring and second ring as shown.The top ring (A) has a R1 mark and the second ring (B) has a R mark. The manufacturing marks (C) must be facing upward.


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

8.Position the ring end gaps as shown:


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

Top Ring Clearance
Standard (New): 0.055-0.080 mm
(0.0022-0.0031 in.)
Service Limit: 0.15 mm (0.006 in.) 

Second Ring Clearance
Standard (New): 0.030-0.055 mm
(0.0012-0.0022 in.)
Service Limit: 0.13 mm (0.005 in.)