Correcting Valve And Valve Seat - Kubota KX080-3 Workshop Manual

WSM KX080-3 Service

Correcting Valve and Valve Seat

NOTE
• Before correcting the valve and seat, check the valve stem
and the I.D. of valve guide section, and repair them if
necessary.
• After correcting the valve seat, be sure to check the valve
recessing.
1) Correcting Valve
1. Correct the valve with a valve refacer.
Factory
Valve face angle
spec.
2) Correcting Valve Seat
1. Slightly correct the seat surface with a 1.047 rad (60 °) (intake
valve) or 0.785 rad (45 °) (exhaust valve) valve seat cutter.
2. Resurface the seat surface with a 0.523 rad (30 °) valve seat
cutter to intake valve seat and with a 0.262 rad (15 °) valve seat
cutter to exhaust valve seat so that the width is close to specified
valve seat width.
Factory
Valve seat width
spec.
3. After resurfacing the seat, inspect for even valve seating, apply
a thin film of compound between the valve face and valve seat,
and fit them with valve lapping tool.
4. Check the valve seating with prussian blue. The valve seating
surface should show good contact all the way around.
Factory
Valve seat angle
spec.
(1) Valve Seat Width
(2) Identical Dimensions
III-S-149
1.047 rad
IN.
60 °
0.785 rad
EX.
45 °
1.6 to 2.0 mm
IN.
0.0630 to 0.0790 in.
2.3 to 2.6 mm
EX.
0.0906 to 0.1024 in.
1.047 rad
IN.
60 °
0.785 rad
EX.
45 °
(A) Check Contact
(B) Correct Seat Width
(C) Check Contact
(a) 0.262 rad (15 °) or 0.523 rad (30 °)
(b) 0.785 rad (45 °) or 1.047 rad (60 °)
(c) 0.523 rad (30 °) or 0.262 rad (15 °)
W10283500
Engine