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MSHappyCampers · 12-06-2022, 10:36 AM

A good friend of mine has a MH with an Onan RV QG 7000 generator. He can start it and it runs for a short time, then cuts off.

He has replaced the fuel pump and fuel filter. Has anyone here had that problem and could you offer suggestions on what to try next? Thanks for your help!

pasdad1 · 12-06-2022, 11:05 AM

I think it will usually flash a code on the start switch which indicates what the computer thinks is the issue.

MSHappyCampers · 12-06-2022, 11:20 AM

Quote:

Originally Posted by pasdad1

I think it will usually flash a code on the start switch which indicates what the computer thinks is the issue.

He told me that it doesn't have a code display.

donr103 · 12-06-2022, 12:27 PM

So.. he needs to think about critters.. critters love to eat the tiniest hole in the fuel line.. above the fuel tank.. and this will not leak fuel but suck air.. the air in f/l will stop generator.. I spent 2 1/2 yrs chasing this because great members here posted a way to test for this and I ignored their opinions.. and could have saved me yrs..

So he needs to isolate the the fuel lines.. 1st.. great members here posted.. that you should try to run generator off your own 5 gal gas can.. so.. disconnect f/l at inlet of f/p and run your own hose to 5 gallon fuel can.. use all safety precautions.. prime and see if runs.. if runs ok.. you know the problem is upstream of f/p towards fuel tank..

Now I could just not get it thru my head.. as to why.. I could not see fuel leaking.. so I ignored this great piece of advice.. but after reading all many great members old posts.. I saw where some spent thousands at shops and techs could never find the problem.. only to drop tank at home.. and find.. that the hard line in back of generator transition to about 20in of rubber f/l over the top of tank.. and you cannot see it.. and some found cracks in f/l ... some found rusted out hose clamps.. and many reported bite marks.. some found that the metal tube that drops down the hole for generator feed into tank .. to be missing or rusted out.. all this after spending thousands at shops.. and only yrs to find it at home..
Critters find the top of fuel tank great place to nest.. eat on f/l and you cannot see it..
So 1st try to bypass this by getting a few gallon or even just a 2 liter pop bottle and prime it and see if runs.. next they post.. after you see if this works.. go ahead and put some good carb cleaner in the can or bottle and run that thru.. I like carb cleaner.. techtron
I found fuel line gets old and small cracks.. I found rusty clamp.. so really he needs to replace all.. I mean all the fuel line that is over 5yrs old.. and clamps

I am ahead a little.. as usual.. 1st.. remove air filter.. then spray starting fluids in while cranking.. if starts.. then you know it's getting spark.. if it starts and dies .. then fuel problem.. if fails to start.. then spark or eng problem.. simple and 10mins.. next if runs on starting fluid.. you need to isolate the the fuel lines.. got it?

After he gets generator running.. if carb has never been cleaned.. in last 5yrs.. that is next.. he need to not take carb off or apart for cleaning.. this short cut works 90 or so % of time.. just remove carb bowl drain.. and spray carb cleaner.. only carb cleaner.. brand does not matter.. it must be carb cleaner.. while holding white paper towels under to catch crud.. then hold figure over drain and spray nozzle and fill carb bowl with carb cleaner .. put drain bolt in. Just hand tight .. . let soak overnight and while waiting.. look inside carb throat past choke.. so you need to gently hold open choke plate.. and look for 2 tiny holes.. maybe one.. use very strong flashlight.. on inside top of throat.. that is your objective.. clean those.. next on bottom throat.. is bigger hole.. usually behind throttle plate.. get that real well.. all with engines off.. now let sit.. overnight with rest.. go out.. remove carb drain.. catch stuff in white paper towels and re spray carb cleaner inside.. catch crud .. see what you get.. if clean.. gently tighten drain.. and prime and adjust main jet.. altitude adjustment until smooth.. check to see if choke works and put air filter back on.. one must change the oil and filter after carb cleaning ... no matter if just done.. you could burn engine bearings if not changed.. .. just as well change air filter if dirty.. onan carbs are made to be cleaned in the field.. so yes.. if this does not help.. you need to take carb apart and clean.. great vids on this by KEVIN CAUDELL on you tube.. it's not hard.. but 90% or there about you only take drain plug and air filter off to clean.. now I am assuming that the choke is working if not.. report back and better opinions will follow
Good luck and keep us posted

pasdad1 · 12-06-2022, 12:35 PM

Quote:

Originally Posted by MSHappyCampers

He told me that it doesn't have a code display.

It’s not a display…..just a light bulb which blinks.

Does the start/stop switch have a light which indicates when the generator is running?

It will flash in a particular pattern if the generator has a problem.

MSHappyCampers · 12-06-2022, 12:38 PM

Thanks! I'll pass this along to him!

MSHappyCampers · 12-08-2022, 02:08 PM

UPDATE! My friend removed the carburetor and cleaned it thoroughly, and now the genny seems to be doing fine! He asked me the thank you guys for the valuable info you provided!