Cummins/Onan B43 / B48 — Returning Unit to Service

Maintenance · Engine

For the Cummins/Onan B43 / B48, from the Cummins/Onan owner's manual.

Applies to: Cummins/Onan B48, Cummins/Onan B43M engine, Cummins/Onan B48M engine

Procedure

1. Remove cover and all protective wrapping; remove plug from the exhaust outlet.
2. Check the tag on the oil base and verify the oil viscosity is still correct for existing ambient temperatures.
3. Clean and check the battery; measure specific gravity (1.260 at 77 F [25 C]) and verify level to the split ring.
4. If specific gravity is low, charge until correct; if level is low, add distilled water and charge.
5. Check that the fuel filter and fuel lines are secure, with no leaks.
6. Check the carburetor and adjust if necessary.
7. Connect the battery.
8. Start the engine.

Full service-parts list: Cummins/Onan B48 →

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.

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