Kawasaki STX-15F - Manual (Page 212)

6-34 ENGINE TOP END
Cylinder, Pistons
Cylinder Wear
•
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.
[A] 10 mm (0.39 in.)
[B] 60 mm (2.36 in.)
Cylinder Inside Diameter
Standard: 82.994 ∼ 83.006 mm (3.2675 ∼ 3.2679 in.)
Service Limit: 83.10 mm (3.272 in.)
Piston Wear
•
Measure the outside diameter [A] of each piston 18 mm
(0.71 in.) [B] up from the bottom of the piston at a right
angle to the direction of the piston pin.
If the measurement is less than the service limit, replace
the piston.
Piston Diameter
Standard: 82.919 ∼ 82.934 mm (3.2645 ∼ 3.2651 in.)
Service Limit: 82.77 mm (3.259 in.)
Piston Ring, Piston Ring Groove Wear
•
Check for uneven groove wear by inspecting the ring seat-
ing.
The rings should fit perfectly parallel to groove surfaces.
If not, replace the piston and all the piston rings.
•
With the piston rings in their grooves, make several mea-
surements with a thickness gauge [A] to determine piston
ring/groove clearance.
Piston Ring/Groove Clearance
Standard:
Top 0.03 ∼ 0.07 mm (0.0012 ∼ 0.0028 in.)
Second 0.02 ∼ 0.06 mm (0.0008 ∼ 0.0024 in.)
Service Limit:
Top 0.17 mm (0.0067 in.)
Second 0.16 mm (0.0063 in.)
Piston Ring Groove Width
•
Measure the piston ring groove width.
○
Use a vernier caliper at several points around the piston.
Standard:
Top [A] 0.92 ∼ 0.94 mm (0.0362 ∼ 0.0370 in.)
Second [B] 1.01 ∼ 1.03 mm (0.0398 ∼ 0.0406 in.)
Service Limit:
Top [A] 1.02 mm (0.0402 in.)
Second [B] 1.11 mm (0.0437 in.)
If the width of any of the two grooves is wider than the
service limit at any point, replace the piston.