Cummins/Onan — Mag-Tronic Ignition Installation
Installation · Ignition system
From a Cummins/Onan service manual covering: GNH-250, GNH-XI0, GNHC4, GNVH450, GV12, GV12 series, GV12-525. Check it applies to your exact model before use.
Applies to: Cummins/Onan GV12
Procedure
- Crank engine until rotor arm centered in timing window and timing marks indexed for No. 1 cylinder.
- Rotate Mag-Tronic drive until rotor arm centered in timing window.
- Position Mag-Tronic to drive assembly, engaging drive coupling; secure capscrews loosely.
- Plug wiring harness into Mag-Tronic.
- Attach timing light to No. 1 cylinder ignition transformer.
- Start engine; rotate Mag-Tronic to obtain correct timing.
- Secure Mag-Tronic in desired position.
Tools required
- timing light Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan GV12 →
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.