- Measure the cylinder liner outside diameter.
- Place the bore gage 20 mm (0.79 in) below the gasket surface.
- Replace the cylinder liner if not within the specifications:
| • | Grade 1: 117.981-117.990 mm (4.6449-4.6453 in) |
| • | Grade 2: 117.991-118.000 mm (4.6453-4.6457 in) |
| • | Grade 3: 118.001-118.010 mm (4.6457-4.64619 in) |
- When replacing the cylinder liner with a service part liner, select liner
grade 1X for factory liner grade 1 and 2, liner grade 3X for factory liner grade 3.
- Measure the piston diameter.
- Place the micrometer 84.6 mm (3.33 in) below the piston
crown, at a right angle to the piston pin bore. The factory measurements are as follows:
| • | Grade A: 114.920-114.929 mm (4.5244-4.5248 in) |
| • | Grade B: 114.930-114.939 mm (4.5248-4.5251 in) |
| • | Grade C: 114.940-114.949 mm (4.5252-4.5255 in) |
- There are 3 different sizes of pistons to be installed from the
factory. The size grades are referred to as "A", "B" and "C".
- The size grade letter is stamped on the piston crown. The engine may come
with any combination of piston sizes.
- Replace the piston. The piston should be the same grade as the cylinder
liner.
- Pistons are supplied either as part of the cylinder liner set, or separately.
- When replacing the cylinder liner, also replace the piston. When replacing
a piston separately, be sure that the piston to cylinder liner clearance is within
factory specifications.
- Measure the piston to cylinder liner clearance.
- Subtract the piston diameter from the cylinder liner bore diameter.
- Correct clearance is 0.092-0.11 mm (0.0036-0.0043 in).
- If the clearance is correct, the piston and the cylinder liner are acceptable
for further use.
- If the clearance is incorrect, try a new piston.
Important: Never attempt to hone the cylinder liner.
Honing may damage the chrome finish on the liners surface.
- If the clearance cannot be brought within factory specifications by the use
of a new piston, the cylinder liner must be replaced. There are no oversize pistons
available.
