Cummins/Onan — Timing Check - Engine Not Running

Testing & diagnosis · Ignition timing

From a Cummins/Onan service manual — check it applies to your exact model before use.

Applies to: Cummins/Onan NHP / NHPV engine

Procedure

1. Connect a continuity test lamp across the ignition breaker points.
2. Touch one prod to breaker box coil terminal, other to a good engine ground.
3. Turn crankshaft counterclockwise until points close.
4. Slowly turn crankshaft clockwise with rotation.
5. Lamp should go out just as the points break (25 degrees BTC).

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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