Engine Block: Pistons: Inspection

Check the piston for distortion or cracks.
NOTE: If a cylinder is bored, an oversized piston must be used.
Measure the piston diameter at distance A from the bottom of the skirt.
A: 5 mm (0.2 in)

Piston Diameter:

Standard (New): 74.980 - 74.990 mm (2.9520 - 2.9524 in)

Service Limit: 74.970 mm (2.9516 in)

Fig 1: Measuring Piston Diameter Distance From Bottom Of Skirt
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Calculate the difference between the cylinder bore diameter (see CYLINDER BLOCK ) and piston diameter.
Piston-to-Cylinder Clearance

Standard (New): 0.010 - 0.040 mm (0.0004 - 0.0016 in)

Service Limit: 0.05 mm (0.002 in)

Fig 2: Identifying Clearance Between Piston And Cylinder Bore
Courtesy of AMERICAN HONDA MOTOR CO., INC.

If the clearance is near or exceeds the service limit, inspect the piston and cylinder block for excessive wear.

Oversize Piston Diameter

0.25: 75.23 - 75.24 mm (2.9618 - 2.9622 in)

0.50: 75.48 - 75.49 mm (2.9716 - 2.9720 in)