Brand New Onan 4000 generator not running

**ARounds** · 06-29-2021, 03:32 PM

Full tank of fuel. Will prime but does not turn over. Started to run for a minute once but then quit. Just got this camper in may. They started and ran generator at the dealer and all went fine.
Just tried to run it today and will not work.
Any suggestions are greatly appreciated

**A.Texas.Yankee** · 06-29-2021, 03:36 PM

Originally Posted by ARounds

Full tank of fuel. Will prime but does not turn over. Started to run for a minute once but then quit. Just got this camper in may. They started and ran generator at the dealer and all went fine.
Just tried to run it today and will not work.
Any suggestions are greatly appreciated

How long ago was dealer demo? How long has fuel been sitting in tank? Hooked up to shore power or just trying to start off battery? Priming from panel or from genny?

Newly full timing in our 2021 Momentum 395MS-R with our tow pig being a 2021 F-450 KR

**ARounds** · 06-29-2021, 03:42 PM

Good questions!
Brand new fuel added to fill tank today with the exception of maybe 2 gallons that were in there since may. Dealer demo was at that time also. Starting off the battery. I had just parked an unhooked from tow vehicle. I did prime and start right on the genny.

**A.Texas.Yankee** · 06-29-2021, 03:48 PM

Originally Posted by ARounds

Good questions!
Brand new fuel added to fill tank today with the exception of maybe 2 gallons that were in there since may. Dealer demo was at that time also. Starting off the battery. I had just parked an unhooked from tow vehicle. I did prime and start right on the genny.

Start with the easy stuff, lol. How long are you holding the prime button down before attempting to start? I know it can take a bit to prime if tank gets low and is refilled.

Also... this had helped me in the past.

https://www.flightsystems.com/pdf/on...ting-guide.pdf

Newly full timing in our 2021 Momentum 395MS-R with our tow pig being a 2021 F-450 KR

**el Rojo** · 06-30-2021, 06:08 AM

Originally Posted by ARounds

Good questions!
Brand new fuel added to fill tank today with the exception of maybe 2 gallons that were in there since may. Dealer demo was at that time also. Starting off the battery. I had just parked an unhooked from tow vehicle. I did prime and start right on the genny.

First, don't assume your truck has the batteries charged. The truck alternator only provides a trickle charge. Sounds like your battery is dead or very weak.

Red

**ARounds** · 06-30-2021, 11:02 AM

Ok thanks I will try with more power. Is it ok to start it connected to shore power and then just disconnect once running?

**ARounds** · 06-30-2021, 11:03 AM

Thank you for the help sheet! So I sprayed a small amount of starter gas into the intake as suggested on that troubleshooting. It tan fine until that is burned off. So maybe a fuel problem?
Also, Holding down prime button for a good 10-15 seconds. Can hear it getting primed and the light clicks on.

**el Rojo** · 06-30-2021, 12:55 PM

Personally I wouldn't start with it plugged into shore power. I've seen mechanics do it but I wouldn't.

Red

**ARounds** · 06-30-2021, 01:04 PM

Yes I didn’t think that was a good idea. I don’t think it is a battery issue but I will check the voltage on it to be sure

**geotex1** · 06-30-2021, 01:53 PM

The ethanol blend gas sitting in it since initial start either clogged the fuel filter or ate a seal in the fuel pump if it fired or ran on starter fluid.