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Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 14489
Experience:  Certified on Onan and Generac generators
19372534
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MY onan 4.0 runs few minutes then starts to surge and shuts

Customer Question

MY onan 4.0 runs for a few minutes then starts to surge and shuts down. Plenty of fuel and oil........
JA: Do you have fuel in the tank? If so, is the shut-off valve open and the fuel clean?
Customer: yes
JA: Do you plan on doing the work yourself?
Customer: hopefully
JA: Anything else we should know to help you best?
Customer: I replace fuel pump
Submitted: 4 months ago.
Category: Small Engine
Expert:  Hank F. replied 4 months ago.

This is due to the engine not getting enough fuel.

Either you have a bad fuel line between the tank and genset, a bad fuel pump, or a bad carburetor.