Cummins/Onan — Gasoline Carburetor Adjustments
Adjustments
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Procedure
- Start engine and allow it to warm up until choke is completely open.
- With no load, turn idle adjustment out until engine speed drops slightly below normal; then turn needle in until speed returns to normal.
- Apply a full load to engine.
- Carefully turn main adjustment in until speed drops slightly below normal; then turn needle out until speed returns to normal.
Specs & values
- Preliminary settings: CCK/CCKA idle 1 to 1-1/4 turns, main 1-1/4 to 1-1/2 turns; CCKB idle 1-1/2 turns, main 2 to 3 turns.
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.