Cummins/Onan W3M-19 — Magneto Breaker Contact Adjustment
Adjustments · Magneto breaker mechanism
For the Cummins/Onan W3M-19, from the Cummins/Onan service manual.
Applies to: Cummins/Onan W3M-19, Cummins/Onan W2C engine
Before you start
- Do not crank engine while gear housing is off the magneto
Procedure
- Remove distributor cap and inspect breaker contacts.
- Clean pitted or eroded contacts, file pyramids square.
- Loosen screw holding stationary contact bracket.
- Move bracket by turning eccentric headed screw in open slot.
- Adjust gap to .015 in.
- Tighten holding screw and recheck gap.
- Work CG grease into cam oil pad and reinstall.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- .015 in. gap
- Magneto spark should jump 7 in. when cranking
Full service-parts list: Cummins/Onan W3M-19 →
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.