Checking And Adjusting Ignition Timing

Ignition timing is controlled by the circuit breaker. Correct ignition timing and correct setting of the circuit breaker contact point gap is absolutely necessary for proper engine operation and performance.

The spark timing cam is advanced automatically as engine speed increases through action of the flyweights in the circuit breaker base. This ensures correct spark timing to suit starting, low speed and high speed requirements.

To check or reset ignition timing proceed as follows:

Remove circuit breaker cover and set circuit breaker contact gap at exactly .018 in. as outlined in previous paragraph.

CHECKING ADVANCED TIMING WITH STROBE TIMING LIGHT (Figure 5-18)

Use a strobe flash timing ligh* (timing gun) to view advanced timing mark (12) on flywheel through accessory plastic view plug screwed into timing inspection hole (11) while engine is running at 2000 rpm. Timing light leads should be connected to front spark plug, ground and positive red wire to battery terminal. Light will flash each time spark occurs (see Figure 5-19). Loosen circuit breaker plate screws (6) just enough so circuit breaker plate (8) can be shifted using a screwdriver in notch (9) as light aimed into inspection hole (11) stops timing mark(12)incenterof hole Timing will retard 30° automatically when engine is stopped.

Rear cylinder advance timing mark is a single drilled dot which should appear on or near the front cylinder advance timing mark while viewing with timing light. See Figure 5-19.

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