Fuel supply to Onan generator in 2014 Cyclone 4100.

[BigJon]

Does anyone know if I can backflush the generator fuel supply line with air without doing any damage to the pickup system inside the dedicated generator tank? I don't know if there are one way valves in line and/or screens/etc. covering the inlet or if just a simple standpipe/bung in the tank?

Also, where is the primer pump located in this fuel supply circuit? Will air move the wrong way through that?

Went to start the generator and it won't stay running without messing with the choke - so it's not getting fuel.


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[Atvmos]

Sounds like to me that this unit has a clogged pilot and or main jet.....pull off the bowl on carb and get the jet out and clean it of varnish.....this happens when gas has been sitting in carb for a while.....hope this helps

 

[Storm1972]

Also keep in mind the Onan generators are famous for having issues with the float, I have had 2 of them now that actually had tiny pin holes in them therefore filling the float making it useless, my new 4200 I bought last year has 1 hour on it and it's having issues already, starts up for 30 seconds and shuts itself down, still looking into this new pronlem


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[avvidclif]

Mine recently had a problem of not running, error codes etc. Turns out the main wiring harness from the genset to the computer was not plugged in all the way. He also reseated the remote control box. Ran it abt 30 hrs last weekend without fail.

 

[oscar]

Still under a 100 hours.... had one case of bad gas and powered through it. Put in stabilizer no matter what time of year and so far so good. Knock on wood. Enough trouble with this unit as it is.

 

[santafedave]

I have a 2008 3795 with the onan genset. I had problems with the genset not starting after 5 tries and throwing error codes. I took my trailer in to the certified onan maintenance facility and they ran diagnostics on it and said that my carb spring had failed. I suffered with this for 3 years and finally read a post here that said they used Seafoam carb cleaner and Seafoam stabilizer. I took the air filter plate off replaced with a new air filter and filled the bowl with the seafoam and ran the genset for 15 minutes and boy what a difference that made! I have been remote camping and traveling the past 6 months running the genset at different elevations and in different environments and it has started and ran with no problems since the Seafoam usage. From what I understand gas that has ethanol in it will varnish the inside of your carbs pretty fast. You need to run these gensets on a monthly basis to keep the varnish out. Give the Seafoam a try and see if it works.

 

[BigJon]

Just checking back in with a follow up the the original post. Pulled the carb off and completely diassassembled and let soak in gas/polaris carbon clean mixture for several days. Put back together blowing things out with compressed air as I went and all works. Other things I learned. 1) There is a electric fuel pump in the supply line. (So small container of fuel won't gravity feed carb - done to check for plugged supply line) 2) doesn't take much to plug things - turns out my blockage was in fuel solenoid fitting at bottom of carb bowl. 3) now using seafoam with every fill of genny tank.


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[santafedave]

Well. After changing out the fuel, tapping on the carb, adding seafoam to the system, changing the air filter, oil and spark plugs I finally broke down and changed the fuel pump and filter. Guess what? My Onan 5500 now runs like a champ! Finally I can head back out to the desert and not have to worry about my genset. Anyway I got the part numbers off of Amazon and used original Onan parts (fuel pump and filter) also I checked out youtube for some tips. The whole install took about a half an hour and the first push of the button my genset fired right up. The Onan fuel pump plugged right into the old plugs and the bolt holes lined up along with the fuel hose's. Happy Camping you all! D.

2008 Cyclone 3795 bought new and still goes like a champ. They build them tough and if you learn how to do your own maintenance can last for years looking new.