Kubota WSM STa-30, Workshop Manual

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1-S36
ST
α
-30 · ST
α
-35, WSM ENGINE
Free Length and Tilt of Valve Spring
1. Measure the free length (A) of valve spring with vernier calipers.
If the measurement is less than the allowable limit, replace it.
2. Put the valve spring on a surface plate, place a square on the
side of the valve spring.
3. Check to see if the entire side is in contact with the square.
Rotate the valve spring and measure the maximum tilt (B).
Check the entire surface of the valve spring for scratches.
If there is any defect, replace it.
W1028935
Valve Spring Setting Load
1. Place the valve spring on a tester and compress it to the same
length it is actually compressed in the engine.
2. Read the compression load on the gauge.
3. If the measurement is less than the allowable limit, replace it.
W1078436
Oil Clearance between Rocker Arm and Rocker Arm Shaft
1. Measure the rocker arm shaft O.D. with an outside micrometer.
2. Measure the rocker arm I.D. with an inside micrometer, and then
calculate the oil clearance.
3. If the oil clearance exceeds the allowable limit, replace the rocker
arm and measure the oil clearance again. If it still exceeds the
allowable limit, replace also the rocker arm shaft.
W1029150
Push Rod Alignment
1. Place the push rod on V blocks.
2. Measure the push rod alignment.
3. If the measurement exceeds the allowable limit, replace the push
rod.
W1029290
Free length (A)
Factory spec.
41.7 to 42.2 mm
1.6417 to 1.6614 in.
Allowable limit
41.2 mm
1.6220 in.
Tilt (B) Allowable limit
1.0 mm
0.039 in.
Setting load /
Setting length
Factory spec.
117.6 N / 35 mm
12.0 kgf / 35 mm
26.4 lbs / 1.3780 in.
Allowable limit
100.0 N / 35 mm
10.2 kgf / 35 mm
22.5 lbs / 1.3780 in.
Oil clearance between
rocker arm and rocker
arm shaft
Factory spec.
0.016 to 0.045 mm
0.00063 to 0.00177 in.
Allowable limit
0.10 mm
0.0039 in.
Rocker arm shaft O.D. Factory spec.
13.973 to 13.984 mm
0.55012 to 0.55055 in.
Rocker arm I.D. Factory spec.
14.000 to 14.018 mm
0.55118 to 0.55189 in.
Push rod alignment Allowable limit
0.25 mm
0.0098 in.
KiSC issued 11, 2006 A