Hey all,I recently posted that the Onan 4000 on my Fleetwood was roaming and would only stay running if I wedged the Governor open, but that is not the case. I went out today to check the adjustment you all told me about and realized that what I was wedging wide open was the CHOKE!!This puts a whole different twist on things and tells me that there is a fuel delivery problem. My first thought is to replace the fuel filter and I got the seafoam to run through it as well. I'm testing it without any load so if any of you have other suggestions I welcome hearing them. I will have to order the fuel filter so it will be next week before I get it replaced.Any help is always greatly appreciated.Thanks,Jake

Sounds to me like deposits in the carburetor. Maybe the Seafoam will work but more likely a disassembly and cleaning is in order.

Replace the fuel filter first. A clogged filter can cause a lot of problems.Plus, then you will know when it was changed.

SeaFoam is a great marketing company.Their product is good at what it was originally designed for: Marine Fuel Stabilizer. It is not so great for all of the other "snake oil" claims that they make for it.Berryman's B12 Chemtool is a MUCH better cleaner.At 2X the recommended dose, it sometimes works miracles.Are you sure you were propping the choke "open" and not CLOSED ??I have the same unit....or very similar.....and got a new carb installed for about $285. Additives and a manual cleaning by the previous owner just didn't get it.I was amazed to find that mine did not have a fuel filter; one was added.

You are right..I'm having to keep the butterfly closed in order to get more fuel to the engine. I will get the fuel filter ordered and see about getting some of that other cleaner.Thanks

Sure sounds like dirty jets in the carb. No real harm in trying the fuel filter, but don't get your hopes up.

Onan 4000 Generator Problem | Good Sam Community

Jerry_Amerson1
Explorer
Aug 23, 2015
You are right..I'm having to keep the butterfly closed in order to get more fuel to the engine. I will get the fuel filter ordered and see about getting some of that other cleaner.

Thanks
Vulcan_Rider
Explorer
Aug 23, 2015
SeaFoam is a great marketing company.

Their product is good at what it was originally designed for: Marine Fuel Stabilizer. It is not so great for all of the other "snake oil" claims that they make for it.

Berryman's B12 Chemtool is a MUCH better cleaner.
At 2X the recommended dose, it sometimes works miracles.

Are you sure you were propping the choke "open" and not CLOSED ??

I have the same unit....or very similar.....and got a new carb installed for about $285. Additives and a manual cleaning by the previous owner just didn't get it.

I was amazed to find that mine did not have a fuel filter; one was added.
gbopp
Explorer
Aug 23, 2015
Replace the fuel filter first. A clogged filter can cause a lot of problems.
Plus, then you will know when it was changed.
tpi
Explorer
Aug 23, 2015
Sounds to me like deposits in the carburetor. Maybe the Seafoam will work but more likely a disassembly and cleaning is in order.

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Onan 4000 Generator Problem

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