Cummins/Onan — Gas Pressure Regulator Adjustment
Adjustments · Fuel System
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Before you start
- Do not permit flame, cigarette, or other igniter near fuel system.
Procedure
- Use manometer reading up to 14 inches water column.
- Shut off gas supply and remove 1/8-inch pipe plug at regulator inlet.
- Connect manometer to read gas supply line pressure.
- Open gas supply line valve.
- Alternately cover and uncover regulator outlet with palm.
- If reading drops, turn adjusting screw inward until reading remains constant.
- Close gas valve, remove manometer, bleed air, install plug.
Tools required
- Manometer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Maximum inlet pressure: 8 ounces (3.45 kPa)
- Minimum inlet pressure: 2 ounces (0.86 kPa)
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.