Cummins/Onan B43 / B48 — Breaker Points Replacement and Adjustment
Adjustments · Ignition breaker points
For the Cummins/Onan B43 / B48, from the Cummins/Onan owner's manual.
Applies to: Cummins/Onan B48, Cummins/Onan B43M engine, Cummins/Onan B48M engine
Before you start
- Make sure the feeler gauge is clean and free of any grease, oil or dirt.
Procedure
- Remove the spark plugs.
- Remove the breaker box cover; rotate the crankshaft clockwise (facing flywheel) until points are fully open.
- Remove the condenser (screw A) and detach the condenser lead and coil lead (screw B).
- Remove the two Allen screws (C) and lift the breaker assembly from the engine.
- Replace the condenser and point assembly with new parts and reinstall in reverse order of removal.
- Rotate the crankshaft clockwise by hand until points are fully open.
- Using a clean flat feeler gauge, set the point gap to the specified value by adjusting the Allen socket head screw (D).
- Replace the breaker box cover, coil wire, spark plugs, and spark plug 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)
Full service-parts list: Cummins/Onan B48 →
Source: Cummins/Onan owner's 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.