wsm wg972-e4 Workshop Manual page 134

WG972-E4, WSM
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 specifica-
tion
2) Correcting Valve Seat
1. Slightly correct the seat surface with a 0.785 rad (45 °) valve
seat cutter.
2. Resurface the seat surface with a 0.262 rad (15 °) valve seat
cutter.
3. After resurfacing the seat, lap the valve as follows.
Factory
Valve seat angle specifica-
tion
(1) Valve Seat Cutter
(A) Check Contact
Valve Lapping
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.
3. After lapping the valve, wash the compound away and apply
prussian blue to the contact surface to check the seated rate.
4. If the valve seats all the way around the valve seat, apply oil and
repeat valve lapping with oil.
5. If the valve contact is incorrect, replace or correct the valve or
correct the contact of valve seating.
IMPORTANT
• When valve lapping is performed, be sure to check the
valve recessing and adjust the valve clearance after
assembling the valve.
1-S43
ENGINE
0.785 rad
IN.
45 °
0.785 rad
EX.
45 °
0.785 rad
IN.
45 °
0.785 rad
EX.
45 °
(a) 0.262 rad (15 °)
(b) 0.785 rad (45 °)
9Y1211108ENS0068US0
9Y1211108ENS0069US0
KiSC issued 07, 2015 A