Kubota M108S, Workshop Manual

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1-S64
M108S, WSM ENGINE
(5) 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 bored. (Refer to “Correcting
Cylinder”.)
W1070089
Correcting Cylinder (Oversize)
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 0.5 mm (0.02
in.) ones.
NOTE
■
• When the oversize cylinder is worn beyond the allowable
limit, replace the cylinder block with a new one.
W10344480
(6) Oil Pump
Rotor Lobe Clearance
1. Measure the clearance between lobes of the inner rotor and the
outer rotor with a feeler gauge.
2. If the clearance exceeds the allowable limit, replace the oil pump
rotor assembly.
W1071254
Cylinder Bore I.D.
Factory spec.
100.00 to 100.022 mm
3.93701 to 3.93787 in.
Allowable limit
100.15 mm
3.9429 in.
(A) Top
(B) Middle
(C) Bottom (Skirt) (a) Right-angled to piston pin
(b) Piston pin direction
Cylinder I.D. (2) Factory spec.
100.500 to 100.522 mm
3.95670 to 3.95755 in.
Maximum wear Allowable limit
100.65 mm
3.9626 in.
Finishing
Hone to 1.2 to 3.0
μ
m Rz
(48 to 110
μ
in. Rz)
∇∇∇.
(1) Cylinder I.D. (Before Correction) (2) Oversize Cylinder I.D.
Clearance between
inner rotor and outer
rotor
Factory spec.
0.040 to 0.16 mm
0.0016 to 0.0062 in.
Allowable limit
0.3 mm
0.01 in.
KiSC issued 06, 2007 A