Cummins/Onan — Fuel Injection Pump Speed Lever Adjustment
Adjustments
From a Cummins/Onan service manual covering: C25 D6, C30 D6, C35 D6, C40 D6, C50 D6, C60 D6. Check it applies to your exact model before use.
Applies to: Cummins/Onan C25 D6, Cummins/Onan C30 D6, Cummins/Onan C35 D6, Cummins/Onan C40 D6, Cummins/Onan C50 D6, Cummins/Onan C60 D6, Cummins/Onan 4BT3.3 engine, Cummins/Onan 4BT3.3-G5 engine, Cummins/Onan 4BT3.3-G7 engine
Procedure
- Make sure the generator set is off and the battery is disconnected.
- If replacing pump or engine, discard speed adjust screw and tamper proof wire and seal.
- Replace the low idle screw; reuse throttle screw nut and acorn nut.
- Pull throttle lever back and screw new low idle screw until it contacts boss.
- Continue tightening until throttle lever is locked in place.
- Tighten the throttle lock nut.
- Install tamper proof wire and seal.
- Set the throttle lever as shown and lock it using seal wire.
Specs & values
- Do not adjust the high idle screw
Full service-parts list: Cummins/Onan C25 D6 →, Cummins/Onan C35 D6 →, Cummins/Onan C50 D6 →, Cummins/Onan C60 D6 →
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.