Kubota WSM B2050 Workshop Manual page 137

B2050, B2350, B2650, B3150, WSM
Free Length and Tilt of Valve Spring
1. Measure the free length (B) 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 (A).
If the measurement exceeds the allowable limit, replace it.
4. Check the entire surface of the valve spring for scratches.If
there is any problem, replace it.
Tilt (A) Allowable limit
Factory specification
Free length (B)
Allowable limit
(A) Tilt
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 specification
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 specification
Oil clearance between
rocker arm and rocker
arm shaft
Allowable limit
Rocker arm shaft O.D. Factory specification
Rocker arm I.D. Factory specification
1-S48
ENGINE
1.0 mm
0.039 in.
37.0 to 37.5 mm
1.46 to 1.47 in.
36.5 mm
1.44 in.
(B) Free Length
9Y1210982ENS0084US0
117.4 N / 31.0 mm
11.97 kgf / 31.0 mm
26.39 lbf / 1.22 in.
100.0 N / 31.0 mm
10.20 kgf / 31.0 mm
22.48 lbf / 1.22 in.
9Y1210982ENS0085US0
0.016 to 0.045 mm
0.00063 to 0.0017 in.
0.10 mm
0.0039 in.
11.973 to 11.984 mm
0.47138 to 0.47181 in.
12.000 to 12.018 mm
0.47244 to 0.47314 in.
9Y1210982ENS0086US0
KiSC issued 03, 2014 A