Piston: Testing and Inspection

1. Check the piston for distortion or cracks.

NOTE: If the cylinder is bored, an oversized piston must be used.





2. Measure the piston diameter at a point 15 mm (0.6 inch) from the bottom of the skirt.

NOTE: There are two standard-size pistons (No Letter or A, and B). The letter is stamped on the top of the piston. Letters are also stamped on the block as cylinder bore sizes.

- Piston Diameter:
- No Letter (or A):
- Standard (New): 86.993-87.006 mm (3.4249-3.4254 inch)
- Service Limit: 86.980 mm (3.4244 inch)
- B:
- Standard (New): 86.983-86.996 mm (3.4245-3.4250 inch)
- Service Limit: 86.970 mm (3.4240 inch)





3. Calculate the difference between the cylinder bore diameter and piston diameter.
- Piston-to-Cylinder Clearance:
- Standard (New): 0.004-0.027 mm (0.0002-0.0011 inch)
- Service Limit: 0.04 mm (0.002 inch)
- If the clearance is near or exceeds the service limit, inspect the piston and cylinder block for excessive wear.
- Oversize Piston Diameter:
- 0.25: 87.233-87.256 mm (3.4344-3.4353 inch)