Cummins/Onan QST30 — Engine Storage - Short Term (One to Six Months)

Maintenance

For the Cummins/Onan QST30, from the Cummins/Onan owner's manual.

Applies to: Cummins/Onan G-Drive, Cummins/Onan QST30, Cummins/Onan QST30 engine

Procedure

1. Operate the engine at high idle until coolant reaches 70 C [160 F]; turn off.
2. Disconnect the fuel lines to the engine fuel filter and the injector return line.
3. Put both fuel lines in a container of diesel fuel.
4. Start the engine; then transfer the supply line to preservative oil.
5. Run until preservative oil flows out of the injector return line; turn engine off.
6. Reconnect the fuel lines, then drain the oil pan sump, oil filters, and fuel filters.
7. Disconnect electrical wiring from the fuel pump solenoid.
8. Crank the engine slowly, spraying lubricating oil into the intake manifold.

Full service-parts list: Cummins/Onan QST30 →

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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