Cummins/Onan — Ignition Timing Check - Engine Not Running
Adjustments
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan NHC-NHCV, Cummins/Onan NHC-NHCV engine
Procedure
- Connect continuity test lamp across breaker points.
- Touch one prod to breaker box terminal with coil lead and other to ground.
- Turn crankshaft counterclockwise until points close.
- Slowly turn crankshaft clockwise.
- Lamp should go out just as points break, indicating ignition at 25° BTC.
Tools required
- Continuity test lamp Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Timing 25° BTC
Full service-parts list: Cummins/Onan NHC-NHCV →
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.