Cummins/Onan — Breaker Point Replacement and Gap Setting
Maintenance · Ignition breaker points
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan MCCK
Procedure
- Remove two screws and cover on breaker box.
- Remove both spark plugs so engine can be easily rotated by hand.
- Remove two mounting screws (A) and pull points out of box just far enough so screw B can be removed.
- Replace points with a new set but do not completely tighten mounting screws (A).
- Rotate crankshaft clockwise (facing flywheel) by hand until points are fully open. Turn screw (C) until point gap measures 0.020 inch (0.51 mm).
- Tighten mounting screws and recheck gap.
- Place a drop of oil on the breaker arm pivot.
Tools required
- Flat thickness gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Breaker point gap 0.020 in (0.51 mm)
Full service-parts list: Cummins/Onan MCCK →
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.