Cylinder distortion
Check the gasketed surface of the cylinder for distortion with a straightedge and thickness gauge, taking a clearance reading at several places as indicated. If the largest reading at any position of the straightedge exceeds the limit, replace the cylinder.
Cylinder distortion
- Service Limit: 0.05 mm (0.002 in)
- 09900-20803: Thickness gauge
Cylinder bore
Inspect the cylinder wall for any scratches, nicks or other damage. Measure the cylinder bore diameter at six places.
Cylinder bore
- Standard: 98.000-98.015 mm (3.8583- .8589 in)
- 09900-20508: Cylinder gauge set
Piston diameter
Using a micrometer, measure the piston outside diameter at 10 mm (0.4 in) from the piston skirt end. If the measurement is less than the limit, replace the piston.
Piston diameter
- Service Limit: 97.880 mm (3.8535 in)
- 09900-20204: Micrometer (75-100 mm)
Piston-to-cylinder clearance
As a result of the previous measurement, if the piston to cylinder clearance exceeds the following limit, replace both cylinder and piston.
Piston to cylinder clearance
Service Limit: 0.12 mm (0.0047 in)
Piston ring to 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.
Piston ring to groove clearance
- Service Limit (1st): 0.18 mm (0.0071 in)
- (2nd): 0.15 mm (0.0059 in)
Piston ring groove width
- Standard (1st): 0.93-0.95 mm (0.0366-0.0374 in)
- 1.55-1.57 mm (0.0610-0.0618 in)
- (2nd): 1.01-1.03 mm (0.0398-0.0406 in)
- (Oil) : 2.51-2.53 mm (0.0988-0.0996 in)
Piston ring thickness
- Standard (1st): 0.86-0.91 mm (0.034-0.036 in)
- 1.38-1.40 mm (0.054-0.055 in)
- (2nd): 0.97 - 0.99 mm (0.038 - 0.039 in)
- 09900-20803: Thickness gauge
- 09900-20205: Micrometer (0 - 25 mm)
PISTON RING FREE END GAP AND PISTON RING END GAP 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
- Service Limit (1st): 7.0 mm (0.28 in)
- (2nd): 8.1 mm (0.32 in)
09900-20101: Vernier caliper
Piston ring end gap
- Service Limit (1st): 0.5 mm (0.02 in)
- (2nd): 0.7 mm (0.03 in)
- 09900-20803: Thickness gauge
Piston pin and pin bore
Using a small bore gauge, measure the piston pin bore inside diameter, and using a micrometer, measure the piston pin outside diameter. If the difference between these two measurements is more than the limits, replace both piston and piston pin.
Piston pin bore I.D.
- Service limit: 22.030 mm (0.8673 in)
- 09900-20602: Dial gauge (1/1000 mm, 1 mm)
- 09900-22403: Small bore gauge (18-35 mm)
Using a micrometer, measure the piston pin outside diameter at three positions.
Piston pin O.D.
- Service Limit: 21.980 mm (0.8654 in)
- 09900-20205: Micrometer (0-25 mm)