Cummins/Onan — Gaseous Fuel System Adjustment
Adjustments · Gas mixer / manual fuel valve
From a Cummins/Onan operator's manual — check it applies to your exact model before use.
Applies to: Cummins/Onan GGHG, Cummins/Onan GGHH, Cummins/Onan V-10 WSG-1068 engine
Before you start
- Fuel is highly flammable and may cause severe personal injury and property damage. Do not allow cigarettes, flame, pilot lights, arcing switches or equipment in area or areas sharing ventilation.
Procedure
- Start the engine and let the set warm up under a partial load (at least 1/4 rated load); on dual fuel sets start with natural gas.
- Connect full rated load and turn the manual fuel valve two turns counterclockwise.
- Slowly turn the manual fuel valve clockwise (lean) until the engine begins to lose speed.
- Slowly turn it counterclockwise (rich) until the engine carries the full load smoothly.
- On dual fuel sets, switch to LPG by closing the manual shutoff valve in the natural gas supply line.
- Reconnect full rated load and turn the LPG flow adjustment valve clockwise until the engine begins to lose speed.
- Slowly turn it back counterclockwise until the engine carries full load smoothly.
Tools required
- Exhaust gas analyzer (for emission sensitive areas) Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan GGHG →, Cummins/Onan GGHH →
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.