Inspection and Service
INSPECTION1. Check the piston for distortion or cracks.
2. Measure the piston diameter at a point 16.0 mm (0.63 inch) from the bottom of the skirt.
Piston Diameter:
Standard (New): 85.975-85.985 mm (3.3848-3.3852 inch)
Service Limit: 85.965 mm (3.3844 inch)
3. Measure wear and taper in directions X and Y at three levels in each cylinder as shown.
- If the measurements in any cylinder are beyond the oversize bore service limit, replace the cylinder block.
- If the block is to be rebored, refer to Piston Clearance Inspection after reboring.
Cylinder Bore Size:
Standard (New): 86.000-86.015 mm (3.3858-3.3864 inch)
Service Limit: 86.065 mm (3.3884 inch)
Reboring Limit: 0.50 mm (0.02 inch)
Reboring Limit: 0.50 mm (0.02 inch)
Oversize
0.25: 86.250-86.265 mm (3.3957-3.3963 inch)
0.50: 86.500-86.515 mm (3.4055-3.4061 inch)
Bore Taper
Limit: (Difference between first and third measurement) 0.05 mm (0.002 inch)
4. Check the top of the cylinder block for warpage. Measure along the edges and across the center as shown.
Cylinder Block Warpage:
Standard (New): 0.07 mm (0.003 inch) max.
Service Limit: 0.10 mm (0.004 inch)
5. Calculate the difference between the cylinder bore diameter and piston diameter.
Piston-to-Block Clearance:
Standard (New): 0.015-0.040 mm (0.0006-0.0016 inch)
Service Limit: 0.08 mm (0.003 inch)
Oversize Piston Diameter
0.25: 86.225-86.235 mm (3.3947-3.3951 inch)
0.50: 86.475-86.475 mm (3.4045-3.4049 inch)
BORE HONING
1. Measure the cylinder bores. If the cylinder block is to be reused, hone the cylinders and remeasure the bores. Only scored or scratched cylinder bores must be honed.
2. Hone the cylinder bores with honing oil and a fine (400 grit) stone in a 60° crosshatch pattern.
NOTE:
- Use only a rigid hone with 400 grit or finer stone, such as Sunnen, Ammco, or equivalent.
- Do not use stones that are worn or broken.
3. When honing is complete, thoroughly clean the cylinder block of all metal particles. Wash the cylinder bores with hot soapy water, then dry and oil them immediately to prevent rusting. Never use solvent, it will only redistribute the grit on the cylinder walls.
4. If scoring or scratches are still present in the cylinder bores after honing to the service limit, rebore the cylinder block. Some light vertical scoring and scratching is acceptable if it is not deep enough to catch your fingernail and does not run the full length of the bore.