Kubota WSM STV32 Workshop Manual page 122

STV32 · STV36 · STV40, WSM
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).
If the measurement exceeds the allowable limit, replace it.
4. Check the entire surface of the valve spring for scratches.
If there is any defect, replace it.
Factory spec.
Free length (A)
Allowable limit
Tilt (B) Allowable limit
(A) Free Length
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.
Factory spec.
Setting load / Setting
length
Allowable limit
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.
Factory spec.
Oil clearance between
rocker arm and rocker
arm shaft
Allowable limit
Rocker arm shaft O.D. Factory spec.
Rocker arm I.D. Factory spec.
1-S50
ENGINE
41.7 to 42.2 mm
1.6417 to 1.6614 in.
41.2 mm
1.6220 in.
1.0 mm
0.039 in.
(B) Tilt
0000005474E
117.6 N / 35.0 mm
12.0 kgf / 35.0 mm
26.4 lbs / 1.3780 in.
100 N / 35.0 mm
10.2 kgf / 35.0 mm
22.5 lbs / 1.3780 in.
0000005475E
0.016 to 0.045 mm
0.00063 to 0.00177 in.
0.10 mm
0.0039 in.
13.973 to 13.984 mm
0.55012 to 0.55055 in.
14.000 to 14.018 mm
0.55118 to 0.55189 in.
0000005476E
KiSC issued 04, 2006 A