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Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 14889
Experience:  Certified on Onan and Generac generators
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Just installed a new gen set (4KFA-6747P) in my motorhome

Customer Question

just installed a new gen set (4KFA-6747P) in my motorhome and it will not pick up the gas to prime the fuel pump. Even tried to use a gas can with a short hose and it still would not prime the pump. The gen set will run if I put fuel into the carb by way of hose and gas can
Submitted: 11 months ago.
Category: Small Engine
Expert:  JON replied 11 months ago.

Hi, my name is ***** ***** welcome to I will be happy to assist you today. Give me a few moments to look over your problem, and I will get right back to you so we can fix the issue and get your machine back to working order

Expert:  JON replied 11 months ago.

From what you are saying the fuel pump as gone out. If the machine will not pump fuel to the carb, the fuel pump needs to be replaced. If you remove the hose from the pump to carb, does fuel spurt out when engine turned over?

Customer: replied 11 months ago.
Customer: replied 11 months ago.
This is a brand new unit
Expert:  JON replied 11 months ago.

I just seen this is a gen set. I am not a generator expert. I can try to help if you would like as I know engines.

If you prefer I will OPT OUT and let another expert take over.

Does this machine have an external fuel pump? Who installed this engine? Is it possible the fuel pump lines got mixed up and hooked to wrong ports?

Expert:  JON replied 11 months ago.

Is this a manul pump that bolts to side of engine or an electric fuel pump?

Does your fuel pump have 3 ports on it? or just 2 ports?

1- fuel tank

2- crankcase

3 - Carb

Expert:  Hank F. replied 11 months ago.

Hello, my name is ***** ***** I am going to assist you with this.

When you press and hold the STOP/PRIME button, do you hear the fuel pump running?

If so, and you have tried using a stand alone can, then the pump is bad.

If you do not hear the pump running, it may have a broken or disconnected wire. Accessing the wires is a pain, and I do not recommend you try, since your unit is still under warranty. If you take the unit apart enough to access the fuel pump, you will void your warranty.

Also, if this is an EVAP unit, make you you install the charcoal canister in accordance with the instructions.

If this is a non-EVAP unit, the charcoal canister is not needed.