- Piston wall
- Cylinder wall
Vertical scratches → Replace the cylinder, and the piston and piston rings as a set.
2. Measure:
- Piston-to-cylinder clearance
a. Measure cylinder bore «C» with the cylinder bore gauge.
Note: Measure cylinder bore «C» by taking side-to-side and front-to-back measurements of the cylinder. Then, find the average of the measurements.
| Cylinder bore «C» | 77.00-77.01 mm (3.0315-3.0319 in) |
| Wear limit | 77.06 mm (3.03 in) |
| Taper limit «T» | 0.005 mm (0.0002 in) |
| Out of round «R» | 0.005 mm (0.0002 in) |
| «C» = maximum of D1-D6 |
| «T» = maximum of D1 or D2 - maximum of D5 or D6 |
| «R» = maximum of D1, D3 or D5 - minimum of D2, D4 or D6 |
b. If out of specification, replace the cylinder, and the pistons and piston rings as a set.
c. Measure piston skirt diameter «P» with the micrometer.
4 mm (0.16 in) «a» from the bottom edge of the piston.
Piston size «P»: 76.975-76.990 mm (3.0305-3.0311 in).
d. If out of specification, replace the piston and piston rings as a set.
e. Calculate the piston-to-cylinder clearance with the following formula.
Piston-to-cylinder clearance = Cylinder bore «C» - Piston skirt diameter «P»
Piston-to-cylinder clearance: 0.010-0.035 mm (0.0004-0.0014 in)
Limit: 0.12 mm (0.0047 in)
f. If out of specification, replace the cylinder, and the piston and piston rings as a set.