Kubota WG972-E2 Workshop Manual page 124

WG972-E2, DF972-E2, 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 spring on a surface plate, place a square on the side of
the 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.
Tilt (A) Allowable limit
Factory spec.
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 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.
S-54
GASOLINE / LPG ENGINE
1.0 mm
0.047 in.
31.3 to 31.8 mm
1.232 to 1.252 in.
28.4 mm
1.118 in.
(B) Free length
W1063303
64.7 N / 27.0 mm
6.6 kgf / 27.0 mm
14.6 lbs / 1.063 in.
54.9 N / 27.0 mm
5.6 kgf / 27.0 mm
12.3 lbs / 1.063 in.
W1063470
0.016 to 0.045 mm
0.00063 to 0.00177 in.
0.15 mm
0.0059 in.
10.473 to 10.484 mm
0.41232 to 0.41276 in.
10.500 to 10.518 mm
0.41339 to 0.41410 in.
W1063697
KiSC issued 01, 2006 A