Do not mix up the top and second ring.
Install the top ring [A] so that the "R" mark [B] faces up.
Install the second ring [C] so that the "RN" mark [D] faces
Apply molybdenum disulfide oil to the piston rings.
If a new piston is used, use new piston ring.
Install the piston with its marking hollow facing forward.
Fit a new piston pin snap ring into the side of the piston
so that the ring opening [A] does not coincide with the slit
[B] of the piston pin hole.
Apply molybdenum disulfide oil to the piston pins and pis-
When installing the piston pin snap ring, compress it only
enough to install it and no more.
Do not reuse snap rings, as removal weakens and
deforms them. They could fall out and score the
Install the cylinder (see Cylinder Installation).
Cylinder Wear Inspection
Since there is a difference in cylinder wear in different di-
rections, take a side-to-side and a front-to-back measure-
ment at each of the two locations (total of four measure-
ments) shown in the figure.
If any of the cylinder inside diameter measurements ex-
ceeds the service limit, replace the cylinder.
10 mm (0.39 in.) [A]
60 mm (2.36 in.) [B]
Cylinder Inside Diameter
67.000 ∼ 67.012 mm (2.637 ∼ 2.638 in.)
Service Limit: 67.10 mm (2.64 in.)
Piston Wear Inspection
Measure the outside diameter [A] of each piston 10 mm
(0.39 in.) [B] up from the bottom of the piston at a right
angle to the direction of the piston pin.
If the measurement is under service limit, replace the pis-
66.950 ∼ 66.960 mm (2.635 ∼ 2.636 in.)
Service Limit: 66.80 mm (2.63 in.)
ENGINE TOP END 5-33