Piston ring-groove clearance

Using a thickness gauge, measure the side clearances of the 1st and 2nd rings. If any of the clearances exceeds the limit, replace both piston and piston rings.

09900-20803: Thickness gauge Piston ring-groove clearance

1st: 0.18 mm (0.007 in)

EB

Service Limit

2nd: 0.15 mm (0.006 in)

1st & 2nd: 0.81 - 0.83 mm (0.032 - 0.033 in)

Standard.

Oil: 1.51 - 1.53 mm (0.059 - 0.060 m)

Piston ring thickness Standard

1st & 2nd: 0.77 - 0.79 mm (0.030 - 0.031 in)

Before installing piston rings, measure the free end gap of each ring using vernier calipers. Next, fit the ring in the cylinder, and measure each ring end gap using a thickness gauge.

If any ring has an excess end gap, replace the ring.

Piston ring free end gap

1st: 4.5 mm (0.18 in)

Service Limit

2nd: 4.6 mm (0.18 in)

09900-20102: Vernier calipers

Piston ring end gap Service Limit

1st & 2nd: 0.5 mm (0.02 in) 09900-20803: Thickness gauge

Oversize piston ring

The following two types of oversize piston rings are used. They bear the following identification numbers.

Oversize oil ring

The following two types of oversize oil rings are available as optional parts. They bear the following identification marks.

Oversize side rail

Just measure out side diameter to identify the size.