Posted 2005-11-08 7:37 AM (#32798) Subject: Onan 4000 Generator, help
Member
Posts: 7
Location: Houston, Texas
We just bought a used trailer. It has a Onan 4000 Generator (gas) w/800 hrs. on it. It will start and run for about 3 minutes then it just kicks off (almost like it is out of gas). We filled both gas tanks up, total of about 7 gallons. It did run for about 2hrs after we got it home w/no trouble. This is our first LQ trailer and we really don't know a lot. We did check the breaker on the generator, but it was fine. Any suggestions? Also when you fill the gas tanks on the trailer, is it possible that the gas goes in too fast and clicks the handle to off, so you think it's full, but then the gas settles and could take more? The guy said it was either two 7 gallon tanks, or two 10 gallon tanks. He said they were probably empty, but again both of them together only held 7gallons. How long should the generator run off of 7 gallons of gas normally?
Posted 2005-11-08 8:01 AM (#32799 - in reply to #32798) Subject: RE: Onan 4000 Generator, help
Veteran
Posts: 222 Location: Kaufman, Texas
I had similar problem with an Onan 4000 in my motor home I used to have. Although it would start and run only a few seconds before shutting off. Turned out to be the bearings. Hope that's not your problem because it was an expensive repair bill.
Posted 2005-11-08 9:18 AM (#32803 - in reply to #32798) Subject: RE: Onan 4000 Generator, help
Member
Posts: 7
Location: Houston, Texas
Okay I checked the oil and it is full, so we can rule that out. I started it again and it started and ran for maybe 2 minutes and then quit. It just doesn't make sense that it ran for over 2 hrs. on Sunday w/no trouble at all.
Posted 2005-11-08 9:18 AM (#32804 - in reply to #32798) Subject: RE: Onan 4000 Generator, help
Regular
Posts: 99 Location: Florida/Georgia
If the gen runs better after filling up the tank(s) then maybe check for weak pump or clogged fuel filter?? Just a couple of (many) things that could be wrong. When I got my RV the first thing I did was to service the gen by replacing plugs,air,oil and gas filters and change oil
Posted 2005-11-08 9:26 AM (#32806 - in reply to #32798) Subject: RE: Onan 4000 Generator, help
Regular
Posts: 60 Location: Ky
Originally written by barrelgirl on 2005-11-08 7:37 AM
We just bought a used trailer. It has a Onan 4000 Generator (gas) w/800 hrs. on it. It will start and run for about 3 minutes then it just kicks off (almost like it is out of gas). We filled both gas tanks up, total of about 7 gallons. It did run for about 2hrs after we got it home w/no trouble. This is our first LQ trailer and we really don't know a lot. We did check the breaker on the generator, but it was fine. Any suggestions? Also when you fill the gas tanks on the trailer, is it possible that the gas goes in too fast and clicks the handle to off, so you think it's full, but then the gas settles and could take more? The guy said it was either two 7 gallon tanks, or two 10 gallon tanks. He said they were probably empty, but again both of them together only held 7gallons. How long should the generator run off of 7 gallons of gas normally?
Thanks.
Could be the fuel filter. Check that first to see if it's getting gas. As to how long it would run on a gal. of fuel, it depends on the load. My 4000 Onan will run about 3 hrs. to a gallon with a heavy load in the summer when it's 90+ outside and humid and the ac is working really hard. Under less than a full load like that, it will run 4-5 hrs on a gal.
I had a problem similar to what you are describing with my Onan this summer. It would run a few minutes and then seem to run out of gas. I could tinker with it and use the prime button to get it started again and it would run a few minutes and then seem to run out of gas. I spoke to an Onan service center and they told me to adjust the little altitude adjustment button on the carb and if I could it to run that way, it really needed a new carb. I made the adjustment and it would run. Once it was warmed up, if you shut it off, it wouldn't start until it cooled. I didn't want ot have to put up with that, so, I took it in and had a new carb. installed. It was avout $240 parts and labor. That solved the problem and it runs like new.
Posted 2005-11-08 10:58 AM (#32810 - in reply to #32798) Subject: RE: Onan 4000 Generator, help
Member
Posts: 24
Location: buchanan,MI
It may be helpful to check the fault code.After shutting down, the indicator light (on the start switch) will blink repeatedly 3 blinks at a time.This indicates a service fault. Press stop once to cause a second two digit code to blink.This will consist of a few blinks (1-4) Then a second set of blinks (1-9). You can also press stop 4 times to retrive the last stored code.
Posted 2005-11-08 12:09 PM (#32812 - in reply to #32810) Subject: RE: Onan 4000 Generator, help
Regular
Posts: 60 Location: Ky
Originally written by justinc on 2005-11-08 10:58 AM
It may be helpful to check the fault code.After shutting down, the indicator light (on the start switch) will blink repeatedly 3 blinks at a time.This indicates a service fault. Press stop once to cause a second two digit code to blink.This will consist of a few blinks (1-4) Then a second set of blinks (1-9). You can also press stop 4 times to retrive the last stored code.
Good idea! On mine, the service fault was to take it for service. If it is something that that the computer can identify though, then you know.
Posted 2005-11-08 5:40 PM (#32821 - in reply to #32798) Subject: RE: Onan 4000 Generator, help
Veteran
Posts: 235 Location: Keymar,Maryland
Don't be to quick to rule out the low oil sensor. Just because there is oil in it does not mean that the sensor is not bad. If it is bad it will give the exact symptoms you are describing. It needs to be tested. Most of these simply ground the ignition system for shutdown. If you know where it connects you can disconnect it for awhile and try running. If it continues to run likely the sensor is bad. Had to get through a weekend by disconnecting mine once. ( well actually never fixed it, check the oil religiously ). Hope this helps.
Posted 2005-11-08 8:50 PM (#32831 - in reply to #32798) Subject: RE: Onan 4000 Generator, help
Member
Posts: 7
Location: Houston, Texas
Well I guess to be safe we will take it in and have it serviced. I found a place for $70 an hr. But they did say that normally they can have the problem diagnosed and fixed in an hour. Of course parts would be extra. So hopefully we can get it in there this week. I was hoping it would be something simple. Thank you all for your help and suggestions. Wish us luck .
Posted 2005-11-09 7:08 AM (#32838 - in reply to #32831) Subject: RE: Onan 4000 Generator, help
Veteran
Posts: 225 Location: Kansas City
Originally written by barrelgirl on 2005-11-08 8:50 PM
Well I guess to be safe we will take it in and have it serviced. I found a place for $70 an hr. But they did say that normally they can have the problem diagnosed and fixed in an hour. Of course parts would be extra. So hopefully we can get it in there this week. I was hoping it would be something simple. Thank you all for your help and suggestions. Wish us luck .
Posted 2005-11-14 10:04 AM (#33005 - in reply to #33003) Subject: RE: Onan 4000 Generator, help
Member
Posts: 7
Location: Houston, Texas
We take it in Wednesday to have it checked. However, this weekend, gas starting coming out of the little silver things above the gas tanks (some type of air vents we were told and when we unscrewed the hose, 2 gallons of gas came pouring out!!!). We were told our gas caps were bad and not ventilating properly and that was the cause. So we did open the gas caps all the way w/out them falling off and it fixed the problem (or so we thought). Afer an hour or so gas started coming out from there. So we are totally confused now. We do believe this was a problem for the previous owners and it explains why the deflector strips were eaten off the trailer in only that area. But hopefully when it is served they will be able to fix everything!!! I will post as soon as we find out. We found out there is so much we don't know and need to know. I guess that's the disadvantages from buying from an individual vs. dealer.
Posted 2005-11-18 9:59 AM (#33211 - in reply to #33005) Subject: RE: Onan 4000 Generator, help
Regular
Posts: 60 Location: Ky
Originally written by barrelgirl on 2005-11-14 10:04 AM
We take it in Wednesday to have it checked. However, this weekend, gas starting coming out of the little silver things above the gas tanks (some type of air vents we were told and when we unscrewed the hose, 2 gallons of gas came pouring out!!!). We were told our gas caps were bad and not ventilating properly and that was the cause. So we did open the gas caps all the way w/out them falling off and it fixed the problem (or so we thought). Afer an hour or so gas started coming out from there. So we are totally confused now. We do believe this was a problem for the previous owners and it explains why the deflector strips were eaten off the trailer in only that area. But hopefully when it is served they will be able to fix everything!!! I will post as soon as we find out. We found out there is so much we don't know and need to know. I guess that's the disadvantages from buying from an individual vs. dealer.
Posted 2005-11-18 2:31 PM (#33221 - in reply to #32798) Subject: RE: Onan 4000 Generator, help
Member
Posts: 7
Location: Houston, Texas
Well $126 bucks later.....apparently it didn't have clamps on the air lines that have to do with the gas lines. There was 1/2 gallon of water in the gas tanks also. The mechanic was not there when we picked up the trailer, so this is all the girl could make out on the ticket. So we still don't know why it wasn't running right to begin with really (unless the water was already in the gas tank prior to all the gas leaking out onto the trailer, but I figured when we were hosing down the trailer to get the gas off of it, water got in there). But the lack of clamps on the correct lines did explain the gas coming out of the area where it was coming out of. But they said they ran it for 1/2 of the day and there were no leaks and it ran fan, so we'll see. I plan on running it a lot this weekend at home, just to check it.
Onan 4000 Generator, help
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