Cummins/Onan B48 — Breaker Points Adjustment
Maintenance · Ignition System
For the Cummins/Onan B48, from the Cummins/Onan service manual.
Applies to: Cummins/Onan B48, Cummins/Onan B48M engine
Before you start
- Make sure feeler gauge is clean and free of grease, oil or dirt
Procedure
- Check breaker points every 100 hours
- Replace points and condenser every 200 operating hours or if pitted/burned
- Remove spark plugs
- Remove breaker box cover
- Rotate crankshaft clockwise until points are fully open
- Remove condenser and detach condenser lead and coil lead
- Remove two Allen screws and lift breaker assembly from engine
- Replace condenser and point assembly with new parts
- Adjust point gap using flat feeler gauge
- Reinstall breaker box cover, coil wire, spark plugs, and cables
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Point gap: 0.021 in. (0.53 mm) - equivalent to 21 degrees BTC
Full service-parts list: Cummins/Onan B48 →
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.