1. Check:
- piston wall
- cylinder wall
Vertical scratches → Rebore or replace the cylinder, and replace the piston and piston rings as a set.
2. Measure: piston-to-cylinder clearance
a. Measure cylinder bore "C" with the cylinder bore gauge.
(a) 40 mm from the top of the cylinder
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.
| Standard | Wear limit | |
| Cylinder bore C: | 95.00~95.01 mm | 95.1 mm |
C = (X+Y)/2 | ||
b. If out of specification, rebore or replace the cylinder, and replace the piston and piston rings as a set.
c. Measure piston skirt diameter "P" with the micrometer.
(b) 5 mm from the bottom edge of the piston.
| Piston size P | |
| Standard | 94.960~94.975 mm |
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:
- 0.025-0.050 mm
- Limit: 0.15 mm
f. If out of specification, replace the cylinder, and replace the piston and piston rings as a set.