QG4000 Won't Start

[Ovation12s]

I purchased a Thor Quantum 2019 last year, recently I had problems with starting QG4000 spec R gas generator. When I inspected I found a nest on top of the generator, probably chipmunk, I have a problem with them here.

Of course this concerned me, but to rule everything out, since I hadn't done any maintenance yet, I replaced everything, spark plug, oil (15W30), fuel filter, and air filter. Plug is gapped correctly, and I'm in WI that's why I chose that oil viscosity. I started it after changing everything, but the oil, and it kicked up right away, but ran a bit rough at first. Then I changed the warm oil out with the 15W30 and ran it again for a while, again started out rough, but smoothed out.

This afternoon, I'm back to the same problem. I get 3 flashes, 3 flashes, 3 flashes, etc, which seems to be the most general and least informative code. One thing I noticed with the old plug, it was extremely black, with either an oily or gas substance on it, I tend to think gas, which makes me think maybe the carburetor is too rich? Any thoughts would be appreciated.

[OldWEB]

Three flashes can be the most informative, you have to then dig into it to find the service code. Also, being in WI, you should be using the recommended 10W30 oil.

[Ovation12s]

Yes as I indicated 3, with a 3 service code repeating which means nothing specific.

[Bob Denman]

Could those unwanted visitors have chewed the insulation off of the wiring?

[kwplot34]

Is the motor turning over but won't start? To rule out a fuel delivery issue spray some starting fluid in the carb while cranking the motor. This will also rule out an ignition problem.

[Jimbo56]

When I bought mine, during the psi, the tech said to hold the stop down to prime it for 5 seconds. Fired right up. Of course he had it running previously. Since then, each time I start it, I have to hold down stop to prime for minimally a count to 30, sometimes 45. On third trip out, discovered it was the low oil shutout keeping it from starting as it was a smidge off level, and had very little oil in it. It took a full quart. Also when they say you need a quarter tank of fuel, yep, they’re correct.

[Jimbo56]

Originally Posted by Ovation12s

Yes as I indicated 3, with a 3 service code repeating which means nothing specific.

That post with the light codes is what makes you go nuts. WTH is a service fault?

[Jimbo56]

Originally Posted by Ovation12s

I purchased a Thor Quantum 2019 last year, recently I had problems with starting QG4000 spec R gas generator. When I inspected I found a nest on top of the generator, probably chipmunk, I have a problem with them here.

Of course this concerned me, but to rule everything out, since I hadn't done any maintenance yet, I replaced everything, spark plug, oil (15W30), fuel filter, and air filter. Plug is gapped correctly, and I'm in WI that's why I chose that oil viscosity. I started it after changing everything, but the oil, and it kicked up right away, but ran a bit rough at first. Then I changed the warm oil out with the 15W30 and ran it again for a while, again started out rough, but smoothed out.

This afternoon, I'm back to the same problem. I get 3 flashes, 3 flashes, 3 flashes, etc, which seems to be the most general and least informative code. One thing I noticed with the old plug, it was extremely black, with either an oily or gas substance on it, I tend to think gas, which makes me think maybe the carburetor is too rich? Any thoughts would be appreciated.

Sounds to me as if it’s either running too rich or starving for air.

[Bob Denman]

How often has this generator been run? Do we have a case of a gummed-up carb?

[OldWEB]

Originally Posted by Ovation12s

Yes as I indicated 3, with a 3 service code repeating which means nothing specific.

It means you have to get the TWO DIGIT code.... From ONAN Trouble Shooting Guide:

SERVICE CHECK FAULT—CODE NO. 3(First-level fault code—Indicates fault with second-level fault code)Corrective Action: Check the second-level fault code by pressing STOP once. The second-level faultcode will have two-digits. The faults are listed in numerical order in the table.


Edit: And no, there is no "33" code.

[abjbrtd]

Originally Posted by Ovation12s

I purchased a Thor Quantum 2019 last year, recently I had problems with starting QG4000 spec R gas generator. When I inspected I found a nest on top of the generator, probably chipmunk, I have a problem with them here.

Of course this concerned me, but to rule everything out, since I hadn't done any maintenance yet, I replaced everything, spark plug, oil (15W30), fuel filter, and air filter. Plug is gapped correctly, and I'm in WI that's why I chose that oil viscosity. I started it after changing everything, but the oil, and it kicked up right away, but ran a bit rough at first. Then I changed the warm oil out with the 15W30 and ran it again for a while, again started out rough, but smoothed out.

This afternoon, I'm back to the same problem. I get 3 flashes, 3 flashes, 3 flashes, etc, which seems to be the most general and least informative code. One thing I noticed with the old plug, it was extremely black, with either an oily or gas substance on it, I tend to think gas, which makes me think maybe the carburetor is too rich? Any thoughts would be appreciated.

Check this link it tells how to get the second code.
https://thecampingadvisor.com/onan-g...des/#tab-con-1

Quoted from the link.
"Code 3 - Service Check

When you see this code, it indicates that there is a problem somewhere on your Onan generator. You will get 3 flashes then a pause, then 3 flashes, then a pause and on it goes till you press the button to get the secondary code."

The codes you're looking for are
3 1, 3 2, 3 5, 3 6 or 3 7
Already mentioned there is no code 3 3

[BASSMAN]

those codes are not always accurate, I had either the 13 or 14 an when I called the local Onan dealer he told me the carb was plugged up, I said if that was the case then It should run when I spray carb cleaner in it just before it shuts down, mine would always start and run for about 15 seconds and die, always the same but the dealer was sure it was a gummed up carb and he said they do not rebuild them and new they are $500.00 but I was still in warranty, so later that day they called and said I had a bad rotor and needed to order it from factory, after they got the generator out they called back and said it was only a broken brush on the slip ring, I picked it up the next day an all was good, after I got home I looked at the paper work and they had also installed a new fuel pump, they said the brush problem has only shown up a few times and they have only replaced the rotor on 3 occasions in the last 15 years. the dealer said the generator needs to be ran every 30 days with a load and the owners manual says it needs to run every 90 days under load, I do the 30 days and had no other problems

[vt800c]

Does anyone have the problem that they have to jump start their generator? EVERY TIME! I have an lp gas one and when I try to hit the starter (After priming) it doesn't turn over. I have a roadside battery that I can use to jump start it, and often I manually turn the flywheel/fan blades over to make sure its not right at the compression point. This gives it a little momentum to get through the harder parts. After a few tries (I figure air in the line) it with turn over and then fire up. Works like a trooper then, until I shut it down. I'm out of ideas to check.

[gp7m8f@yahoo.com]

Originally Posted by Ovation12s

I purchased a Thor Quantum 2019 last year, recently I had problems with starting QG4000 spec R gas generator. When I inspected I found a nest on top of the generator, probably chipmunk, I have a problem with them here.

Of course this concerned me, but to rule everything out, since I hadn't done any maintenance yet, I replaced everything, spark plug, oil (15W30), fuel filter, and air filter. Plug is gapped correctly, and I'm in WI that's why I chose that oil viscosity. I started it after changing everything, but the oil, and it kicked up right away, but ran a bit rough at first. Then I changed the warm oil out with the 15W30 and ran it again for a while, again started out rough, but smoothed out.

This afternoon, I'm back to the same problem. I get 3 flashes, 3 flashes, 3 flashes, etc, which seems to be the most general and least informative code. One thing I noticed with the old plug, it was extremely black, with either an oily or gas substance on it, I tend to think gas, which makes me think maybe the carburetor is too rich? Any thoughts would be appreciated.

The float is stuck in the down position not allowing the needle to seat allowing the bowl to over fill with fuel thus to rich . The float must never stick it must drop freely

[Jimbo56]

Originally Posted by vt800c

Does anyone have the problem that they have to jump start their generator? EVERY TIME! I have an lp gas one and when I try to hit the starter (After priming) it doesn't turn over. I have a roadside battery that I can use to jump start it, and often I manually turn the flywheel/fan blades over to make sure its not right at the compression point. This gives it a little momentum to get through the harder parts. After a few tries (I figure air in the line) it with turn over and then fire up. Works like a trooper then, until I shut it down. I'm out of ideas to check.

How old. Sounds like vacuum lock. But not very familiar with lp.