Cummins/Onan — Checking Centrifugal Breaker Points
Adjustments · Centrifugal switch
From a Cummins/Onan operator's manual covering: 12.0MDJF-53CR, 12.0MDJF-53CR4, 12.0MDJF-54R, 12.0MDJF-55DR, 12.0MDJF-57R, 15.0MDJ F .. .4R 196 D, 15.0MDJF, 15.0MDJF-3CR, 15.0MDJF-3CR4, 15.0MDJF-5DR. Check it applies to your exact model before use.
Applies to: Cummins/Onan 12.0MDJF-53CR, Cummins/Onan MDJF (Onan J-series diesel) engine, Cummins/Onan MDJF engine
Procedure
- Rotate engine crankshaft a few degrees counterclockwise before adjusting points (use socket wrench on flywheel retaining screw).
- Measure gap with a thickness gauge; set gap at .040 in.
- Loosen and move the stationary contact to correct gap.
- Dress slightly burned points smooth with a file or fine stone; replace burned or faulty points.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Set gap at .040 in
Full service-parts list: Cummins/Onan 12.0MDJF-53CR →
Source: Cummins/Onan operator'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.