Cummins/Onan — Ignition Timing Adjustment

Adjustments · Magneto

From a Cummins/Onan service manual covering: 10C, 10CW, 10CW-150R, 5CW, 5TW-0R, 6CW-54R, 7.5C, 7.5CW, 8CW. Check it applies to your exact model before use.

Applies to: Cummins/Onan 10CW, Cummins/Onan 10CW-150R

Procedure

1. Remove magneto end cap.
2. Adjust breaker points to .015-inch gap.
3. Remove air cover from right hand cylinder.
4. Slowly turn engine until IMP mark centers in timing hole.
5. Listen for sharp click from magneto.
6. If click before mark, timing fast; if after, slow.
7. Loosen magneto mounting screws and turn magneto to advance or retard.
8. Repeat until proper timing attained.

Full service-parts list: Cummins/Onan 10CW →, Cummins/Onan 10CW-150R →

Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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