Procedures

NOTE: If new piston rings are to be fitted without reboring, deglaze the cylinder walls with a hone, without increasing the bore diameter, to provide a cross-hatch finish. After honing, thoroughly clean the piston bores to remove all traces of foreign matter.

Measuring Ring Gap:

1. Check the compression ring in the applicable cylinder, held square to the bore with the piston. Gap limits: 0.44 to 0.56 mm (0.017 to 0.022 in). Use a fine-cut flat file to increase the gap if required. Select a new piston ring if the gap exceeds the limit.

NOTE: Gapping does not apply to oil control rings.

2. Temporarily fit the compression rings to the piston.
3. The ring marked TOP must be fitted with the marking uppermost and into the second groove. The chrome ring is for the top groove and can be fitted either way round.

Measuring Ring Clearance:

4. Check the compression ring clearance in the piston groove. Clearance limits: 0.05 to 0.10 mm (0.002 to 0.004).

Piston Ring Placement:

5. Fit the expander ring into the bottom groove making sure that the ends butt and do not overlap.
6. Fit two ring rails to the bottom groove, one above and one below the expander ring.
7. Fit the second compression ring with the marking TOP uppermost and the groove, either way round.