Check each piston for scuffing, scoring, wear and other defects. Replace any piston that is defective.

Check each piston ring for breakage, damage and abnormal wear. Replace the defective rings.

When the piston requires replacement, its rings should also be replaced.

Check that the piston pin fits in the piston pin hole. Replace any piston and pin assembly that is defective. The piston pin must be smoothly pressed by hand into the pin hole (at room temperature).

Measure the piston ring side clearance. If the measured value exceeds the service limit, insert a new ring in the ring groove to measure the side clearance.

If the clearance still exceeds the service limit, replace the piston and rings together. If it is less than the service limit, replace the piston rings only.

To measure the piston ring end gap, insert a piston ring into the cylinder bore. Position the ring at right angles in the cylinder wall by gently pressing it down with a piston. Measure the gap with a feeler gauge. If the gap exceeds the service limit, replace the piston ring.

note

The mark can be found on the upper side of the ring next to the end.

When the connecting rod cap is installed, make sure that the cylinder numbers, marked on rod end cap at disassembly, match.

When a new connecting rod is installed, make sure that the notches holding the bearing in place are on the same side.

Replace the connecting rod if it is damaged at either end of the thrust faces. If it has a stratified wear in, or if the surface of the inside diameter of the small end is severely rough, replace the rod.