Mazda 121 - Valve Seat

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)
IN
E"'il
db
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B-51