If any trouble arises that can be traced directly to the magneto, examine the breaker box mechanism first; the locknut at the point adjustment may have worked loose, and the points may be closed, or some abnormal condition may exist that has caused the points to pit and stick.
Breaker point adjustment varies from the thickness of a sheet of writing paper to one sixty-fourth of an inch; an adjustment anywhere between these two points usually results in satisfactory operation.
If the magneto does not function properly after the breaker box and external wire connections have been examined, the trouble is probably due to an internal short circuit, and repairs of this nature should only be undertaken by an expert magneto mechanic.
To remove the magneto, disconnect the high tension wires leading to the spark plugs from the distributor terminal posts, tag and number each wire to correspond with the number stamped below the post. If the engine fires 1-2-4-3, number three wire will be attached to number four terminal post. Then remove the ground wire and disconnect the universal joint and remove the metal strap, or the set screws, from the base.
To Time the Magneto.—Place the timing control lever in a fully retarded position; remove the plates from the distributor housing to expose the distributor brush and gear, then remove the cover from the interruptor housing to permit observation of the points, and rotate the armature in the direction which it is driven until the point begins to open. At this point mesh the distributor gear so that the distributor lever will just be touching one of the segments which connect to the distributor terminal posts.
Timing the Magneto with the Engine.—Rotate the crank shaft until No. 1 cylinder is up on dead center on the compression stroke; rotate the armature, with the spark lever in full retard until the distributor arm begins to make contact with No. 1 segment, and mesh the timing gear at this point.
CHAPTER XVIII
NORTH EAST IGNITION SYSTEM
The N.-E. Model O Distributor Ignition System is used on Dodge Brothers cars. This system provides high tension ignition for the engine by transforming the low voltage of the starter generator or the battery into a high voltage capable of jumping freely between the spark plug electrodes. This is accomplished through the agency of an induction coil, the primary winding of which, in series with an interruptor or contact breaker, receives current under normal running conditions from the starter generator. The starting and lighting battery, however, supplies this current instead of the generator whenever the engine is starting or running very slowly.
At each interruption of the primary current there is set up in the secondary winding of the coil a high tension current, and this current flows from the coil through a high tension cable to the distributor rotor from which point it is selectively conducted to the proper spark plug. Upon reaching the spark gap in the plug, it jumps from the inner electrode to the outer one, which is grounded, and then returns through the engine frame to the grounded end of the secondary winding on the ignition coil. The high tension spark thus produced in the cylinder ignites the gas and so brings about the necessary combustion.
Wiring ([Fig. 62]).—As will be evident upon reference to the accompanying wiring diagram, the primary circuit of the ignition system leads from the positive terminal of the battery through the charging indicator to the ignition switch binding post marked “Bat.,” thence, when the switch is turned on, through the switch to one of its binding posts marked “Ign. Coil.” Continuing on from this point through the ignition coil and the breaker contacts, it returns to the second switch binding post marked “Ign. Coil,” where it passes through the switch again. It then finally reaches the grounded negative terminal of the battery through the grounded terminal of the switch and the car frame.