Kubota WSM STa-30, Workshop Manual

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1-S47
ST
α
-30 · ST
α
-35, WSM ENGINE
(E) Cylinder
Cylinder Wear
1. Measure the I.D. of the cylinder at the six positions (see figure)
with a cylinder gauge to find the maximum and minimum I.D.’s.
2. Get the difference (Maximum wear) between the maximum and
the minimum I.D.’s.
3. If the wear exceeds the allowable limit, bore and hone to the
oversize dimension. (Refer to “Correcting Cylinder”.)
4. Visually check the cylinder wall for scratches. If deep scratches
are found, the cylinder should be bores. (Refer to “Correcting
Cylinder”.)
W1034389
Correcting Cylinder (Ov0.25 mm)
1. When the cylinder is worn beyond the allowable limit, bore and
hone it to the specified dimension.
2. Replace the piston and piston rings with oversize (+0.25 mm)
ones.
NOTE
■
• When the oversize cylinder is worn beyond the allowable
limit, replace the cylinder block with a new one.
W1034448
Cylinder I.D.
Factory
spec.
D1463-M
82.000 to 82.0022 mm
3.22835 to 3.22921 in.
D1703-M
87.000 to 87.022 mm
3.42519 to 3.42606 in.
Maximum wear
Allowable
limit
D1463-M
+0.15 mm
+0.0059 in.
D1703-M
+0.15 mm
+0.0059 in.
(A) Top
(B) Middle
(C) Bottom (Skirt) (a) Right-angled to Piston Pin
(b) Piston Pin Direction
Oversize cylinder I.D.
Factory
spec.
D1463-M
82.250 to 82.272 mm
3.23819 to 3.23906 in.
D1703-M
87.250 to 87.272 mm
3.43503 to 3.43590 in.
Maximum wear
Allowable
limit
D1463-M
+0.15 mm
+0.0059 in.
D1703-M
+0.15 mm
+0.0059 in.
Finishing
Hone to 2.2 to 3.0 mm
μ
R max.
∇∇∇
(0.00087 to 0.00118 in.
μ
R max.)
Parts Name Model Code Number Marking
Piston
D1463-M 1A011-21900 0.25 OS
D1703-M 1A091-21901 0.25 OS
Piston ring assembly
D1463-M 1A011-21090 0.25 OS
D1703-M 1A091-21091 0.25 OS
(1) Cylinder I.D. (Before Correction) (2) Oversize Cylinder I.D.
KiSC issued 11, 2006 A