Kubota GR1600EC2, Workshop Manual, Page: 116 / 241

1-S49
GR1600EC2, 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”.)
W10360060
Correcting Cylinder
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 ones.
NOTE
■
• When the oversize cylinder is worn beyond the allowable
limit, replace the cylinder block with a new one.
W10367470
(6) Oil Pump
Rotor Lobe Clearance
1. Measure the clearance between lobes of the inner rotor and the
outer rotor with a thickness gauge.
2. If the clearance exceeds the factory specifications, replace the oil
pump rotor assembly.
W10378950
Cylinder I.D.
Factory spec.
67.000 to 67.019 mm
2.63779 to 2.63854 in.
Allowable limit
67.169 mm
2.6445 in.
(A) Top
(B) Middle
(C) Bottom (Skirt) (a) Right-angled to Piston Pin
(b) Piston Pin Direction
Cylinder I.D.
[Oversize]
Factory spec.
67.250 to 67.269 mm
2.64764 to 2.64839 in.
Allowable limit
67.419 mm
2.65429 in.
Finishing
Hone to 1.2 to 2.0
μ
m Rmax.
∇∇∇∇
(0.000047 to 0.000079 in. Rmax.)
Oversize Part Name Code Number Marking
0.25 mm
0.0098 in.
Piston 16851-21900 025
Piston ring assembly 16851-21090 025
(1) Cylinder I.D. [Before Correction] (2) Cylinder I.D. [Oversize]
Rotor lobe clearance Factory spec.
0.03 to 0.14 mm
0.0012 to 0.0055 in.
KiSC issued 07, 2006 A