Piston Ring: Service and Repair

REMOVAL
Refer to the illustration for the removal procedure.

INSTALLATION
Reverse the removal procedure to install, noting the following:





Oil Ring
1. Fit the oil ring spacer into the piston ring groove.

NOTE:
- The side rails and spacer may be installed in either direction
- New spacers and side rails are colored for identification of their sizes.
Standard: not colored
0.50 mm oversize: blue
1.00 mm oversize: yellow





2. Install the upper side rail. To install the side rail, first fit one end of the rail into the piston groove, then press the remaining portion into position with a finger (see illustration).

CAUTION: Use of a ring expander to expand the side rail end gap can break the side rail, unlike other piston rings. Do not use a piston ring expander when installing side rail.

3. Install the lower side rail in the same procedure as described in step 2.
4. Make sure that the side rails move smoothly in either direction.

Piston Rings





1. Using piston ring expander, fit No. 2 and then No. 1 piston ring into position. The ring end is provided with identification mark. Identification mark for the No. 1 ring is 1R and No. 2 ring is marked with 2R.





2. Install piston rings with identification mark facing up, to the piston crown side.
3. Size marks on piston rings are as follows:
Size and size mark
Standard: NONE
0.50 mm oversize: 50
1.00 mm oversize: 100





4. Arrange the piston ring and oil ring gaps (side rail and spacer) as shown in the figure.