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I I f f
radio develops excessive noise
radio develops excessive noise
is a pronounced engine
is a pronounced engine
fective cables (broken).
fective cables (broken).
The rotor and distributor cap electrodes should be
The rotor and distributor cap electrodes should be
inspected for burning. Replace the rotor if the elec-
inspected for burning. Replace the rotor if the elec-
trode is burned on the top or worn too short.
trode is burned on the top or worn too short.
3. DISTRIBUTOR RESISTANCE TEST
3. DISTRIBUTOR RESISTANCE TEST
This test indicates the resistance of the ignition pri-
This test indicates the resistance of the ignition pri-
mary circuit from the distributor side of the coil, through
mary circuit from the distributor side of the coil, through
the points and the distributor ground. Excessive re re
the points and the distributor ground. Excessive
sista
sistance
nce in this porti
in this portion of the igniti
vent the coil from producing sufficient output for good
vent the coil from producing sufficient output for good
over-all ignition. To perform test proceed as follows:
over-all ignition. To perform test proceed as follows:
(1) Turn the Selector Switch to the "CALIBRATE"
(1) Turn the Selector Switch to the "CALIBRATE"
position and adjust Dwell Calibrator until the Dwell
position and adjust Dwell Calibrator until the Dwell
Meter reads on the set line (test leads separated).
Meter reads on the set line (test leads separated).
(2) Leave selector switch in "CALIBRATE" posi-
(2) Leave selector switch in "CALIBRATE" posi-
tion, connect tach-dwell red lead to distributor terminal
tion, connect tach-dwell red lead to distributor terminal
i i
of coil and black lead to a good ground.
of coil and black lead to a good ground.
(3) Turn the ignition switch ON. Observe the dwell
(3) Turn the ignition switch ON. Observe the dwell
meter reading. Meter pointer should be well within
meter reading. Meter pointer should be well within
black
black
bar
bar
marked
marked
the reading is zero or outside of black bar, crank en-
the reading is zero or outside of black bar, crank en-
gine with the starter until meter pointer moves as far
gine with the starter until meter pointer moves as far
to the right as possible. (This will indicate that breaker
to the right as possible. (This will indicate that breaker
points are closed.) A reading now within black indi-
points are closed.) A reading now within black indi-
cates a normal distributor primary circuit.
cates a normal distributor primary circuit.
If the reading is outside the black bar, high resist-
If the reading is outside the black bar, high resist-
ance is present in the distributor primary circuit.
ance is present in the distributor primary circuit.
. .
(4) Remove the test lead from the distributor ter-
(4) Remove the test lead from the distributor ter-
minal of coil and connect to the following points:
minal of coil and connect to the following points:
a. Distributor primary terminal (outside).
a. Distributor primary terminal (outside).
b. Distributor primary terminal (inside).
b. Distributor primary terminal (inside).
c c . . B B r r e e a a k k e e r r
bracket).
bracket).
d. Ground side of contact points.
d. Ground side of contact points.
e. Distributor housing.
e. Distributor housing.
(5) Repeat test at each connection until a notice-
(5) Repeat test at each connection until a notice-
able change occurs in the meter reading. If a bad
able change occurs in the meter reading. If a bad
connection or faulty lead is indicated, clean, tighten
connection or faulty lead is indicated, clean, tighten
or replace as necessary and repeat test (4).
or replace as necessary and repeat test (4).
If bad points are indicated, remove distributor for
If bad points are indicated, remove distributor for
complete inspection, service, testing and calibration.
complete inspection, service, testing and calibration.
4. I
4. IDL
DL E R.P
E R.P .M.
The engine idle r.p.m. setting should be tested and
The engine idle r.p.m. setting should be tested and
miss, check
miss, check
on of the ignition system will pr
on system will pre- e-
"DISTRIBUTOR
"DISTRIBUTOR
RESISTANCE".
RESISTANCE".
p p o o i i n n t t
t t e r e rm i
m in n a l a l b b r a
r ac c k e
k et t
.M.
TEST
TEST
or
or
if there
if there
(2) Connect the red lead of the test unit to the dis-
(2) Connect the red lead of the test unit to the dis-
for
for
de-
de-
tributor primary terminal at coil and the black lead to
tributor primary terminal at coil and the black lead to
a good ground.
a good ground.
(3) Turn the selector switch to the 8 "LOBE" posi-
(3) Turn the selector switch to the 8 "LOBE" posi-
tion.
tion.
(4) Turn the tachometer r.p.m. switch to the 1000
(4) Turn the tachometer r.p.m. switch to the 1000
r.p.m. position.
r.p.m. position.
(5) With the engine at normal operating tempera-
(5) With the engine at normal operating tempera-
ture (off fast idle), momentarily open the throttle and
ture (off fast idle), momentarily open the throttle and
release to make sure there is no bind in the linkage
release to make sure there is no bind in the linkage
and that the idle speed screw is against its stop.
and that the idle speed screw is against its stop.
(6) Note engine r.p.m. on 1000 r.p.m. scale and ad-
(6) Note engine r.p.m. on 1000 r.p.m. scale and ad-
just
just the
the carburetor
r.p.m.
r.p.m.
5.
5.
DISTRIBUTOR
DISTRIBUTOR
The "deg
The "degrees of Dwel
points are the degrees of rotation through which the
points are the degrees of rotation through which the
breaker points remain closed. This is also commonly
breaker points remain closed. This is also commonly
referred to as "dwell angle" or "cam angle".
referred to as "dwell angle" or "cam angle".
Correct distributor point dwell is essential for good
Correct distributor point dwell is essential for good
ignition performance and point life.
ignition performance and point life.
(1) Connect the tach-dwell red lead to the distrib-
(1) Connect the tach-dwell red lead to the distrib-
If
If
utor terminal of the coil and the black lead to a good
utor terminal of the coil and the black lead to a good
ground.
ground.
(2) Turn the selector switch to the 8 "LOBE" posi-
(2) Turn the selector switch to the 8 "LOBE" posi-
tion.
tion.
(3) Start the engine and operate at 475 to 500 r.p.m.,
(3) Start the engine and operate at 475 to 500 r.p.m.,
engine at normal operating temperature (off fast idle).
engine at normal operating temperature (off fast idle).
(4) Observe dwell meter reading and compare to
(4) Observe dwell meter reading and compare to
specifications. If the dwell reading is within specifica-
specifications. If the dwell reading is within specifica-
tions, the point gap cam rubbing block and breaker
tions, the point gap cam rubbing block and breaker
arm are all in satisfactory condition.
arm are all in satisfactory condition.
If dwell reading is not within specifications, incor-
If dwell reading is not within specifications, incor-
rect point gap, defective cam, worn rubbing block or
rect point gap, defective cam, worn rubbing block or
( i ( in n s s u u l l a a t t e e d d
distorted breaker arm is indicated.
distorted breaker arm is indicated.
6. DWELL VARIATION
6. DWELL VARIATION
This test indicates the mechanical condition of the
This test indicates the mechanical condition of the
distributor.
distributor.
parts cause dwell variations which will effect ignition
parts cause dwell variations which will effect ignition
timing.
timing.
(1) With engine at idle speed and distributor vac-
(1) With engine at idle speed and distributor vac-
uum line disconnected and with the test leads con-
uum line disconnected and with the test leads con-
nected as in the point dwell test, turn the tachometer
nected as in the point dwell test, turn the tachometer
r.p.m. switch to the 500 r.p.m. position.
r.p.m. switch to the 500 r.p.m. position.
(2) Slowly increase the engine speed to 1500 r.p.m.
(2) Slowly increase the engine speed to 1500 r.p.m.
carburetor idle
idle screw
screw to to obtain
obtain 475500
POINT
POINT
DWELL
DWELL
rees of Dwell" l" of of the
the distrib
Excessive
Excessive
wear
wear
in
in
distributor
distributor
475500 engine
engine
distributor
utor breaker
breaker
mechanical
mechanical
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