Kubota G21LD / G21HD Workshop Manual page 118

G21LD · G21HD, WSM
Cylinder Wear
1. Measure the cylinder liner I.D. 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".)
Cylinder liner I.D.
Maximum wear
(A) Top
(B) Middle
(C) Bottom (Skirt)
Correcting Cylinder
1. When the cylinder is worn beyond the allowable limit, bore and
hone it to the specified dimension.
Cylinder liner I.D.
Maximum wear
Finishing
2. Replace the piston and piston rings with oversize ones.
Oversize Part Name
Piston
0.25 mm
0.0098 in.
Piston ring assembly
NOTE
n
• When the oversize cylinder is worn beyond the allowable
limit, replace the cylinder block with a new one.
(1) Cylinder I.D. (Before Correction)
1-S46
67.000 to 67.019 mm
Factory spec.
2.63779 to 2.63854 in.
67.169 mm
Allowable limit
2.64445 in.
(a) Right-angled to Piston Pin
(b) Piston Pin Direction
67.250 to 67.269 mm
Factory spec.
2.64764 to 2.64839 in.
67.419 mm
Allowable limit
2.65429 in.
Hone to 1.2 to 2.0 mR max.
(0.000047 to 0.0079 in.R max.)
Code Number
1E051-21901
16853-21091
(2) Oversized Cylinder I.D.
ENGINE
W10360060
Marking
025 OS
025 OS
W10367470
KiSC issued 08, 2007 A