Valve Seat - Mazda 121 Workshop Manual

INSPECTION / REPAIR
Valve Seat
1. Inspect the contact surtace of each valve seat and valve
face for the following:
(1) Roughness
(2) Damage
2. lf necessary, resurfacethe valve seat with a45" valve seat
cutter and/or resurface the valve face.
3. Apply a thin coat ol Prussian blue to the valve lace.
4. Inspectthe valve seating by pressing the valve againstthe
seat.
(1) li blue does not appear 3600 around the valve face, re-
place the valve.
(2) lf blue does not appear 3600 around the valve seat,
resurlace the seat.
EAT CONTACT WIDTH
if
5. Measure the seat contact width.
width
DIMENSION !
mm (in)
B3
IN, EX
0.8-1.4 (0.031-0.0s5)
6. Verifv that the valve seating posiiion is at the center of the
vave Tace.
(1) lf the seating position is too high, correct the valve seat
with a 70o cutter and a 45" cutter
(2) lf the seating position is too low correct the valve seat
with a 40' cutter and a 45o cutter
7. Seat the valve to the valve seat with lapping compound.
8. Inspect the sinking ol the valve seat.
Measure the protruding length {djmension L) of the valve
stem.
Dimension L: 41.05-41.95mm (1.616-1.652 in)
I N
E"'il
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B-51