Piston Ring, Engine

Check for clearance between the piston ring and ring groove. If it exceeds the limit, replace the ring or piston, or both.
Standard value:
Number 1 0.03 - 0.07 mm (0.0012 - 0.0027 inch)
Number 2 0.02 - 0.06 mm (0.0008 - 0.0023 inch)
Limit 0.1 mm (0.003 inch)
Insert the piston ring into the cylinder bore. Force the ring down with a piston, the piston crown being in contact with the ring, to correctly position it at right angles to the cylinder wall. Then, measure the end gap with a feeler gauge. If the ring gap is excessive, replace the piston ring.
Standard value:
Number 1 0.15 - 0.30 mm (0.006 - 0.012 inch)
Number 2 0.28 - 0.43 mm (0.011 - 0.017 inch)
Oil 0.10 - 0.40 mm (0.003 - 0.015 inch)
Limit:
Number 1, Number 2 0.8 mm (0.03 inch)
Oil 1.0 mm (0.03 inch)