Cummins/Onan — Ignition Timing - Engine Running
Adjustments
From a Cummins/Onan owner's manual covering: 4.0CCK, 4.0CCK-3CR, 5.0 CCK. Check it applies to your exact model before use.
Applies to: Cummins/Onan 4.0CCK, Cummins/Onan 4.0CCK-3CR, Cummins/Onan 5.0 CCK, Cummins/Onan CCK engine
Procedure
- Connect timing light
- Remove timing hole plug
- Start engine and check mark aligns with 19° BTC
- Loosen breaker box screws and move left to advance or right to retard
- Start engine and verify
- Tighten screws and replace timing plug
Tools required
- timing light Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 19° BTC
Full service-parts list: Cummins/Onan 4.0CCK →, Cummins/Onan 4.0CCK-3CR →, Cummins/Onan 5.0 CCK →
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.