Kawasaki STX-15F service manual Piston Ring Thickness, Piston Ring End Gap

ENGINE TOP END 6-35

Cylinder, Pistons

Piston Ring Thickness

•Measure the piston ring thickness.
○
Use the micrometer to measure at several points around
the ring.
Piston Ring Thickness
Standard:
Top [A]	0.87 ∼	0.89 mm (0.0343 ∼	0.0350 in.)
Second [B]	0.97 ∼	0.99 mm (0.0382 ∼	0.0390 in.)
Service Limit:
Top [A]	0.80 mm (0.0315 in.)
Second [B]	0.90 mm (0.0354 in.)

If any of the measurements is less than the service limit on either of the rings, replace all the rings.

NOTE

○When using new rings in a used piston, check for un- even groove wear. The rings should fit perfectly parallel to the groove sides. If not, replace the piston.

Piston Ring End Gap

•Place the piston ring [A] inside the cylinder, using the pis- ton to locate the ring squarely in place. Set it close to the bottom of the cylinder, where cylinder wear is low.

•Measure the gap between the ends of the ring with a thick- ness gauge [B].

Piston Ring End Gap

Standard:

Top	0.25 ∼	0.40 mm (0.0098 ∼	0.0157 in.)
Second	0.40 ∼	0.55 mm (0.0157 ∼	0.0217 in.)
Service Limit:
Top	0.7 mm (0.0276 in.)
Second	0.8 mm (0.0315 in.)

If the end gap of either ring is greater than the service limit, replace all the rings.