Cummins/Onan — Short Term Storage Preparation (One Month to 6 Months)

Maintenance · Engine storage

From a Cummins/Onan owner's manual covering: K1800, K2000E, K38, K50, KT38, KTA38, KTA50, KTTA38, KTTA50, KtA38, KtA50, KttA38. Check it applies to your exact model before use.

Applies to: Cummins/Onan K38, Cummins/Onan K50, Cummins/Onan KTA38, Cummins/Onan KTA50, Cummins/Onan K38 and K50 engine

Procedure

1. Operate the engine at HIGH IDLE until coolant temperature is 70 C [160 F]. Turn the engine 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 and START the engine.
4. After the engine runs smoothly, transfer the fuel supply line to a container of preservative oil and operate until preservative oil flows out the injector return line.
5. Turn the engine OFF and connect the fuel lines to the fuel filter and injector return line.
6. Drain the oil pan sump, oil filters, and fuel filters.
7. Disconnect the electrical wiring from the fuel pump solenoid; turn the fuel pump manual shutoff valve counterclockwise until it stops.
8. Crank the engine slowly and spray lubricating oil into the intake manifold and air compressor inlet.
9. Drain the coolant and put a warning tag on the engine.
10. Store the engine in a dry area with uniform temperature and bar the crankshaft two or three revolutions every 3 to 4 weeks.

Full service-parts list: Cummins/Onan K38 →, Cummins/Onan K50 →, Cummins/Onan KTA38 →, Cummins/Onan KTA50 →

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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