Cummins/Onan — Starting Procedure After Extended Shutdown or Oil Change
Operation · lubricating oil system
From a Cummins/Onan owner's manual covering: 4B3.9, 4BT 3.9, 4BTA 3.9, 6B5.9, 6BT 5.9, 6BTA5.9, B3.9, B5.9, C8.3. Check it applies to your exact model before use.
Applies to: Cummins/Onan 4B3.9, Cummins/Onan 6BTA5.9, Cummins/Onan B5.9 engine
Procedure
- Disconnect the electrical wire from the fuel pump solenoid.
- Rotate the crankshaft, using the starting motor, until oil pressure appears on the gauge or the warning lamp goes out.
- Connect the electrical wire to the fuel pump solenoid valve.
- Start the engine; refer to normal starting procedures.
- Refer to fuel system - bleeding to vent the fuel system.
Source: Cummins/Onan owner'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.