Figure 5-5. Breaker Plate

TM 10-3930-623-12

Figure 5-5. Breaker Plate

NOTE

i. Set point opening to 0.021 inch as shown in

The contact point pressure must fall

within specified limits. Weak tension

j. Reinstall rotor, position and lock distributor cap

will cause chatter resulting in arcing

to housing.

and burning of the points and an

ignition miss at high speed, while

k. Start engine and test dwell and ignition timing

excessive tension will cause undue

wear of the contact points, cam and

using standard shop equipment as instructed by the

rubbing block. Breaker arm spring

equipment maker.

tension should be 19-23 ounces. The

contact point pressure should be

5-32. SPARK PLUG SERVICING (see figure 5-7).

checked with a spring scale, The

scale should be hooked to the

Clean spark plugs with standard spark plug

breaker lever and the pull exerted at

90 degrees at the breaker lever. The

cleaning equipment. If the electrodes are excessively

reading should be taken just as the

burned, install new spark plugs.

points separate. The pressure can be

adjusted by bending the breaker

2. Using a round feeler gage, check for proper gap

lever spring.

If the pressure is

between the spark plug electrodes. Adjust the gap to

excessive, it can be decreased by

0.025 inch by bending the side electrode only. Do not

pinching the spring carefully.

attempt to bend the center electrode for any reason.

increase pressure, the lever must be

removed from the distributor so the

spring can be bent away from the

5-33. DELETED

lever.

Avoid excessive spring

distortion.

5-6