Cylinder Block Inspection

Inspection





1. Measure wear and taper in directions X and Y at three levels in each cylinder.





Cylinder Bore Size

Oversize
0.25: 90.250 - 90270 mm (3.5531 - 3.5539 inch)
0.50: 90.500 - 90.520 mm (3.5630 - 3.5638 inch)

Bore Taper
Limit: (Difference between first and third measurement) 0.05 mm (0.002 inch)
Reboring Limit: 0.5 mm (0.02 inch)
- If 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.

NOTE: Scored or scratched cylinder bores must be honed.

2. Check the top of the cylinder block for warpage. Measure along the edges and across the center.








SURFACES TO BE MEASURED

Bore Honing
1. Measure the cylinder bores. If the cylinder block is to be reused, hone the cylinders and remeasure the bores.





2. Hone the cylinder bores with honing oil and a fine (400 grit) stone in a 60 degree crosshatch pattern.

NOTE:
- Use only a rigid hone with a 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.

NOTE: 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.

NOTE: 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.

NOTE:
- After honing, clean the cylinder thoroughly with hot soapy water.
- Only scored or scratched cylinder bores must be honed.