Kawasaki STX-15F - Manual (Page 213)

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.