Fitting Piston Rings

1. Set the oil ring spacer in the piston ring groove. Then set the upper side rail. Thereafter, set the lower side rail.

NOTE:
a. The side rails and spacer may be installed in either direction.
b. New spacers and side rails are colored for identification of their sizes. Standard size color is None, 0.50 mm oversize color is Blue and 1.00 mm oversize color is Yellow.





2. A side rail can be easily installed by fitting one end of the side rail in the piston groove and pressing the remaining portion into position by finger as shown.

CAUTION: Use of ring expander to expand the side rail end gap can break the side rail, unlike other piston rings.

3. Make sure that the side rails move smoothly in either direction.





4. Using piston ring expander, fit No. 2 and then No. 1 piston ring into position.






NOTE:
a. Note the difference in shape between No. 1 and No. 2 piston rings.
b. Install piston rings No. 1 and No. 2 with their side having marks facing up (on the piston crown side).

5. Liberally coat the circumference of the piston, piston ring and oil ring with engine oil.





6. Arrange the piston ring and oil ring gaps (side rails and spacer) as shown in the illustration.
7. Install the piston and connecting rod assembly with the front mark (arrow mark) on the top of the piston facing towards the camshaft sprocket.





8. While holding the piston rings securely with a suitable piston ring compressor, insert the piston and connecting rod assembly into the cylinder bore. Hammering it in with a strong force could cause damage to the piston rings and crankshaft pins.