Mazda 626 1981 - 01-12

Fig. 1
-40
Fig.
1-41
Fig.
1
-42
•
Fig.
1-43
1
1- C-
14.
Checking Piston
Carefully
inspect the piston and replace
if
it is severely
scored, scratched
or
burned.
Measure the diamet
er
of the piston without the piston
pin fitted
by
means
of
a micrometer.
The
standard diameter are as sho
wn
in
Fig.
1-41.
If
the wear is severe, replace
the
piston.
1-C-15.
Checking Piston
Clearance
Check
the clearance between each piston and
cylinder
by
measuring
the
diameter
of
the pi
sto
n and cylinder.
Measure
the pist
on
diameter
at
right angle
to
the
pis-
ton
pin and
18.5
mm
(0.73
in)
below
the
ring groove.
The
standard clearance is
0.
036
- 0.
075
mm
(0.0014 -
0.0030
in).
If
the
clearance exceeds
0.15
mm (0.006 in).
rebore
the
cylinders and use the oversize pistons and rings,
referring
to
Par.
1- C- 13.
A:
79.954
±
0.01
mm
(3.1478
±
0.0004
in)
B:
79.980
mm
(3.
1489
in)
C:
79.550
mm
(3.1319
in)
1-
C-16.
Checking
Piston Ring
Groove
Remove the
carbon
from the pi
sto
n ring grooves
by
using a ring groove cleaner
or
a broken piece
of
piston
ring.
Wi
th
a feeler gauge, check the side clearance
of
the
piston rings
at
several places.
If
1t
is improper, replace the pi
sto
n rings.
Standard:
Top
ring
Second
ring
Limit
0.030
-
0.070
mm
(0.
0012
-
0.0028
in)
0.030
-
0.064
mm
(0.0012- 0.0025 in)
0.15
mm
(0.006
in)
1- C- 17. Checking Piston Ring End Gap
Place
t
he
piston ring in the cyli
nder
bore
below
the
ring travel, using a piston head
to
push
the ring in
squarely.
Check
the piston ring
end
gap
with
a feeler gaug
e.
Standard:
Top
&
second ring
0.2
-
0.4
mm
(0.008 -
0.016
in)
Oil
ring
0
.3
-
0.9
mm
(0.012 -
0.035
in)
Limit
1.0
mm
(0.039
in)
I :
12
.,