vance (distributor degrees) specified,
with double breaker points, and distribu-
degree of spark advance. The arrow flashes
tributors with double breaker points the
should conform to the spark advance (dis-
cam angle on each set of points are checked
tributor degrees) specified.
separately and each must show the same
c. Turn the speed control fully clock-
reading on the dwell meter. To block one
wise, set the directional control switch in
set of breaker points open while testing the
the off position, remove the coil lead, and
other set, place a piece of fiber or any
snap the power switch off.
nonconducting material between the points.
h. Turn the speed control (14) clockwise
33. Cam Lobe Tests for
Vacuum Controlled
and reduce the speed to its lowest point
Spark Advance
on the 0-2500 range, switch the speed range
a. Connect the
coil No. 1
lead (5, fig. 4)
selector to 0-500 range and adjust the dis-
to the distributor terminal. Adjust the
tributor speed to 200 rpm. Disconnect the
speed of the distributor to the rpm called
cam angle lead from the distributor and
for in the applicable TM or manufacturer's
specifications for the distributor. Then
or 33 as applicable.
connect vacuum hose to distributor as de-
31. Cam Lobe Test
for Single Coil
as covered in specifications and check
Ignition Systems
a. Connect coil No. 1
lead (5, fig. 4) to
b. Turn the speed control fully clock-
the distributor terminal. Observe cam pat-
wise, set the direction control switch in
tern of the stroboscope at 200 rpm. Adjust
the off position, remove the coil lead and
the protractor disk with the protractor set-
vacuum hose, and snap the power switch
ting knob so a flashing cam lobe alines
off.
with the 4 - 6 - 8 mark as shown in figure
34. Synchronizing Points on Double Coil,
Double Breaker Arm, and Vertical
b. Check the pattern on both speed
ranges from 200 to 2000 rpm. Image pat-
Type Distributors
tern should remain steady. "Dancing" or
a. Double coil, double breaker distribu-
misalignment of lines at high speed only,
indicates bouncing of points, poor contact,
the use of two ignition coils in order to
weak springs, or friction in breaker arm
synchronize points and check their cam
bearing.
lobe accuracy. Connect coil No. 1 lead and
c. Turn the speed control fully clock-
coil No. 2 lead (5, and 8, fig. 4) to the two
wise, set the direction control switch in
distributor terminals.
the off position, remove the coil lead, and
b. Set the stroboscope protractor ring
snap the power switch off.
for the proper distributor specification
setting.
32. Cam Lobe Tests
for Fly-ball Governor
c. Turn the direction control switch to
Spark Advance
the direction in which the distributor shaft
a. Connect the
coil No. 1
lead (5, fig. 4)
is driven in the vehicle and observe pat-
to the distributor terminal. Aline the 4-6-8
tern of disk. Turn the power switch on and
mark on the protractor disk to coincide
the speed control setting to 200 rpm.
with one of the arrow flashes as shown in
d. Turn the synchronizing screw on the
breaker arm plate (fig. 12) and, ignoring
b. Adjust rpm as indicated inapplicable
one set of flashes, adjust the flashes until
TM or manufacturer's specifications and
the best match to all lines are achieved.
observe the arrow flashes opposite the
If there is still more than 1 degree jog in
tester protractor disk to determine the
any line, the cam is inaccurate.
d e g r e e of spark advance. The arrow
lock
breaker
flashes should conform to the spark ad-