Piston Ring, Engine

PISTON RING SIDE CLEARANCE





^ Measure the side clearance of piston ring and piston ring groove with feeler gauge.
Standard:
Top ring: 0.045 - 0.080 mm (0.0018 - 0.0031 inch)
2nd ring: 0.030 - 0.070 mm (0.0012 - 0.0028 inch)
Oil ring: 0.065 - 0.135 mm (0.0026 - 0.0053 inch)
Limit:
Top ring: 0.11 mm (0.0043 inch)
2nd ring: 0.10 mm (0.0039 inch)
^ If the measured value exceeds the limit, replace piston ring, and measure again. If it still exceeds the limit, replace piston also.

PISTON RING END GAP





^ Make sure that cylinder bore inner diameter is within the specification. Refer to "Cylinder Bore Inner Diameter".
^ Lubricate with new engine oil to piston and piston ring, and then insert piston ring until middle of cylinder with piston, and measure the piston ring end gap with feeler gauge.
Standard:
Top ring: 0.23 - 0.33 mm (0.0091 - 0.0130 inch)
2nd ring: 0.33 - 0.48 mm (0.0130 - 0.0189 inch)
Oil ring: 0.20 - 0.50 mm (0.0079 - 0.0197 inch)
Limit:
Top ring: 0.54 mm (0.0213 inch)
2nd ring: 0.80 mm (0.0315 inch)
Oil ring: 0.95 mm (0.0374 inch)
^ If the measured value exceeds the limit, replace piston ring, and measure again. If it still exceeds the limit, re-bore cylinder and use oversize piston and piston rings.