Cummins/Onan Onan P4500i Inverter / P4500 — Draining the Fuel Tank
Maintenance
For the Cummins/Onan Onan P4500i Inverter / P4500, from the Cummins/Onan operator's manual.
Applies to: Cummins/Onan P4500
Before you start
- DO NOT use an electric pump.
Procedure
- Unscrew the fuel tank cap and remove the fuel screen filter.
- Using a commercially available gasoline hand pump, siphon the gasoline into an approved container.
- Reinstall the fuel screen filter and the fuel tank cap.
- Start the generator and allow it to run until the engine stops.
- Push the battery switch to the OFF position.
- Disconnect the battery quick-connect plug.
- Remove the spark plug.
- Put a teaspoon of engine oil into the cylinder and pull the recoil handle until resistance is felt.
- Reinstall the spark plug; leave the spark plug boot disconnected.
- Install the engine service cover.
Tools required
- Gasoline hand pump Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan P4500 →
Source: Cummins/Onan operator'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.