FIG. 6. Centrifugal Advance Adjustment
FIG. 8. Checking Breaker Point Alignment
Breaker Point Alignment
Connect the test set vacuum line to the fitting on the diaphragm.
The breaker points must be accurately aligned and stroke
squarely to assure normal breaker point life. Misalignment of these
Set the test set at 0 degree advance, 0 vacuum, and at 1000
breaker point surfaces can cause premature wear, overheating and
Turn the cam so that the breaker points are closed and check
Check the advance at the vacuum setting given in the
the alignment of the points (Figure 8). If the distributor is in the
engine, close the points by proceeding as follows: I. With the
ignition switch off and the primary wire disconnected from the
If the advance is incorrect and adjustment is required,
coil. crank the engine with an auxiliary starter switch.
disconnect the vacuum line and insert a 1/8 inch socket head
Using the tool shown (Figure 9) and exerting very light pressure,
wrench in the end of the diaphragm (Figure 7). Turn the wrench
align the breaker point bracket. Do not bend the breaker arm.
clockwise to increase the vacuum advance or counterclockwise
After the breaker points have been properly aligned, adjust the
to decrease it. Do not change the original rpm setting when
breaker point gap or dwell.
going to a different vacuum setting. If the other settings are not
within limits, there is incorrect spring tension. leakage in the
vacuum chamber and/or line.
To check the diaphragm for leakage: Install the distributor
tester. Do not connect the vacuum line to the distributor.
Adjust the vacuum pressure of the distributor tester to obtain 25
inches Hg. Hold your hand over the end of the tester's vacuum hose
and note the reading obtained. Do not exceed 25 inches Hg.
If the reading is 25 inches Hg or less, connect the tester's
vacuum line to the vacuum fitting on the diaphragm to be tested
without changing any of the adjustments.
The gauge reading should not be less than it was above. If it is
less, the diaphragm is leaking and should be replaced.
FIG. 9. Using Alignment Tool
Breaker Point Gap Adjustment
A scope, a dwell meter, or a feeler gauge can be used to check
the gap of new breaker points.
A scope or a dwell meter should be used to check the gap of
used breaker points. Due to the roughness of used points, it is not
advisable to use a feeler gauge to check the gap.
FIG. 7. Vacuum Advance Adjustment