Cummins/Onan 6.5NH - 3CR / 6000 A — Carburetor Adjustment (Gasoline)
Adjustments
For the Cummins/Onan 6.5NH - 3CR / 6000 A, from the Cummins/Onan service manual.
Applies to: Cummins/Onan NH engine
Before you start
- Do not force the needle valves against their seats; this will bend the needle.
Procedure
- Be sure the ignition system works and the governor is adjusted; allow the engine to warm up.
- Apply a full load to the engine.
- Turn the main adjustment in until speed drops slightly below normal, then turn out until speed returns to normal.
- With no load, turn the idle adjustment out until speed drops slightly below normal, then in until speed returns to normal.
- Set the throttle stop screw to allow 1/32 inch clearance to the stop pin at no load.
Tools required
- Screwdriver Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Throttle stop clearance 1/32 inch
- Float level 1/8 inch
- Needle 1 to 1-1/2 turns off seat for starting
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.