- Oversize pistons should be selected according to the largest bore cylinder.
NOTE:
The size of piston is stamped on top of the piston.
- Measure the outside diameter of the piston to be used.
- According to the measured O.D (Outer Diameter), calculate the new bore size.
NOTE:
New bore size = piston O.D + 0.02 to 0.04 mm (0.0008 to 0.0016 in) (clearance between piston and cylinder) - 0.01 mm (0.0004 in) (honing margin.)
- Bore each of the cylinders to the calculated size.
CAUTION:
To prevent distortion that may result from temperature rise during honing, bore the cylinder holes in the firing order.
- Hone the cylinders, finishing them to the proper dimension (piston outside diameter + gap with cylinder).
- Check the clearance between the piston and cylinder. Standard: 0.02-0.04 mm (0.0008-0.0016 in)
NOTE:
When boring the cylinders, finish all of the cylinders to the same oversize. Do not bore only one cylinder to the oversize.