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gauge wire) and the secondary winding (high
num ber
of
turns
wound
up with fine gauge
wire).
DISTRIBUTOR
(see Fig. 120)
Description
Ignition distributor
is
a
MARELLI
S123A
type.
This
device
comprises the
automatic
advance
assembly,
the
contact
breaker unit on
low
voltage
circuit,
the high voltage distributor
cap
and condensor.
Features
-
Automatic
advance: 14
0
- Direction
of rotation:
CCW
Automatic advance
operating range
:
see
d iagram
on
Fig.
122.
Contact
breake
r
gap
0.42
~
0.48
mm.
(.016 -
.018").
Contacts
pressure
:
475
±
50
g.
AUTO
MATIC
SPAR
K ADVANCE
DEVICE
(see Fig.
121)
Consisting
of two suitably
shaped
centrifugal
weights
(1) having
ful crum
on
the
studs
(2)
inserted in plate
(3)
which
is solid with
shaft (4).
At
a
predeterm
ined
No.
of
revs
weights
begin
to
move and by means
of
a suitable slot
in
sa~
me they entrain the pins
(5) and
(6) secured to
plate (7) which is solid with cam (8), thus
cau~
sing
an
angular displacement
of the
cam with
respect
to the
distributor
shaft.
Return
of
weigh-
ts is obtain
ed
by means of return
springs (10)
hooked
to
the
studs
(2)
and
to
the
pins (11)
on
plate.
Rest
position of
return
springs is
de-
term ined
by
pi
n
(6) contacting the end of the
plate slot Lock plale (12)
secures
th
e
position-
ing of weights and
cam, especially
when
strjp~
ping
down distributor rotor.
Every engine speed
requires
the equivalent
ignition moment accordingy
to a
curve
(advan~
ce curve) which is then
determined in relation
104
I
2
,
,
,
,
Oft
position
Adv~nted
position
Fig
.
121
-
Operation
01
the
automatic spark advance
device.
1.
Weight
-
2. Stud
-
3. Plale,
solid
with shalt
-
4.
Shaft
-
5.
Cam control pin
-
6.
Cam control pin
- 7.
Plate,
solid
with cam
-
8. Cam
- 9.
Plate slot -
10.
Return spring •
11.
Spring stud -
12. Lock
plate.
"
•
~
•
~
,
0
•
~ •
•
c
o
.. 5
•
f
"
c
o
I
AUTD~ATIC
SPARK ADVANCE orA
GRA
M
: I I
,t'I
-
-'1
,-I
I
TOI.r.nc.t l~
..
Y
'
J..-'l/
I
·h
'/1'
, "
I
"
,
)'
I
,
,
,(
Toler~nte:!:l
o iri
I
,
,
I
,
,
,
,
,
,
I
,
,
,
[-
,it
·
,
I
SOO
"XlO
10
"'"
Oi$tributor sh
..
ft RPM
Fig. 122
"
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