Kubota ,RCK60B-23BX, Руководство по ремонту

Страница: 171 / 436

6.1.10 Lapping valve
IMPORTANT
• When valve lapping is performed, be sure to
check the valve recessing and adjust the valve
clearance after assembling the valve.
1. Apply compound evenly to the valve lapping
surface.
2. Insert the valve into the valve guide. Lap the valve
onto its seat with a valve flapper or screwdriver.
3. After lapping the valve, wash the compound away
and apply oil, then repeat valve lapping with oil.
4. Apply prussian blue to the contact surface to check
the seated rate. If it is less than 70%, repeat valve
lapping again.
6.1.11 Checking free length and tilt of valve
spring
(A) Tilt (B) Free length
1. Measure the free length (B) of valve spring with
vernier calipers. If the measurement is less than the
allowable limit, replace it.
BX1880 and BX2380
Free length (B)
Factory specifi-
cation 31.3 to 31.8 mm
1.24 to 1.25 in.
Allowable limit
28.4 mm
1.12 in.
BX2680
Free length (B)
Factory specifi-
cation 37.0 to 37.5 mm
1.46 to 1.47 in.
Allowable limit
36.5 mm
1.44 in.
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.
BX1880 and BX2380
Tilt (A) Allowable limit
1.2 mm
0.047 in.
BX2680
Tilt (A) Allowable limit
1.0 mm
0.039 in.
4. Check the entire surface of the valve spring for
scratches. If there is any problem, replace it.
6.1.12 Checking 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. ENGINE
SERVICING
6. Servicing
3-60
BX1880,BX2380,BX2680,RCK60B-23BX,RCK54-23BX,RCK48-18BX,RCK60D-26BX,RCK54D-26BX
KiSC issued 03, 2019 A