I started out with a no start Onan 4000. Not even a pop. I was getting code 36. I removed and cleaned the carb as best I could. I can now get about a 5 second run and now only flashing 3. i tried to retrieve codes but only now getting 3. Fuel pump is pumping when priming but I didn't check the fuel pressure due to time. From searching the net, I find that it is generally a fuel delivery issue and the non rebuildable carb seems to get blamed for a lot. So, is it time for a tech or do I throw a carb at it and hope for the best? I don't have a problem attempting more trouble shooting since I am a cheap bastard but just checking to see if I should cut to the chase with a shop.Steve

I have no help for you but it cracked me up when you said you are a cheap bastard! I can relate!! LOL

Just from personal experience, go on-line to Amazon and buy a new carb. I'm as cheap as the come, infact thought I could use my extended warranty to cover the gen problem, only to be screwed by Camping World, who I'm sure knew that the warranty wouldnt cover it, yet didn't have a problem charging me $175 diagnostic fee! The new carb cost $161. Not only do I have a peace of mind knowing it's new, but also I know how to fix it. It took about 15 min to take off the old and put on the new. I had the same prob with my son's ATV and after pulling the carb apart and getting into every crack with cleaner, I still ended up taking it to a mechanic. Again, I would highly suggest order a new carb and be done with it. I wish I would have started there? Just my 2 cents?

I had to replace my carb and at the time I also put in a fuel shut off. Now I let it run out of gas every time I shut it off. Haven't had a problem since.

dieseldan723 wrote:I had to replace my carb and at the time I also put in a fuel shut off. Now I let it run out of gas every time I shut it off. Haven't had a problem since.I'll be doing this. Good idea. I did get 8 years out of it so I guess I'll spring for a new carb. Can't find it on Amazon though so. Off to Ebay.

Do you guys use Stabil or something in the gas? I'm going to guess they're gummed up from sitting with the el cheapo fuel they sell us nowadays. I put in Stabil most every time I fill the gas tank but if I'm going on a trip I'll give it a good dose of Seafoam to clean it out while we're using it.

Another No Start Onan | Good Sam Community

MEXICOWANDERER
Explorer
Aug 08, 2014
I hate it when my stuff doesn't work.

My Dad used to say that about me...
SMarquez
Explorer
Aug 08, 2014
A new carb fixed it. I just ran it with a load for 90 minutes. I also added Stabil to the tank.
I hate it when my stuff doesn't work.
SMarquez
Explorer
Aug 06, 2014
Well, I ordered a carb. It is flooding now. My plug was black and soaked. A fresh plug was soaked as well. I had the air filter off and held the choke open and it still flooded. I post up if that fixes it this weekend.
Bobbo
Explorer II
Aug 06, 2014
ONAN recommends 2 hours a month under 50% load. They stipulate a single run of 2 hours rather than 30 minutes 4 times a month.
wilanddij
Explorer
Aug 06, 2014
Had been running my Onan for about an hour each month and then had to let it sit longer for some reason I can't remember now. Wouldn't start. Ended up tearing the carb apart 3 times before I got all the crud out. Wish I'd have thought of the fuel shutoff a long time ago. If you have a p/n for the shutoff valve can you ID it for us slow learners?
Y-Guy
Moderator
Aug 05, 2014
Since this isn't specific to Toy Haulers I'm going to move this thread over to the Tech Issues Forum.

Y-Guy
TxTiger
Explorer
Aug 05, 2014
dieseldan723 wrote:
d-mac1 wrote:
Do you guys use Stabil or something in the gas? I'm going to guess they're gummed up from sitting with the el cheapo fuel they sell us nowadays. I put in Stabil most every time I fill the gas tank but if I'm going on a trip I'll give it a good dose of Seafoam to clean it out while we're using it.

Yep, Stabil and non-ethanol fuel. Also started the generator EVERY month and ran it for 15 minutes. STILL gummed up after 3 months. Since I installed the shut-off and run it dry I have not had any problems.

15 minutes is not enough exercise. You also need to put a load on the generator, not just start it. The manufacturer recommends around 1 hr per month of load.

I had luck starting mine every month, even with one year old ethanol gas using stabil for ethanol.
dieseldan723
Explorer
Aug 05, 2014
d-mac1 wrote:
Do you guys use Stabil or something in the gas? I'm going to guess they're gummed up from sitting with the el cheapo fuel they sell us nowadays. I put in Stabil most every time I fill the gas tank but if I'm going on a trip I'll give it a good dose of Seafoam to clean it out while we're using it.

Yep, Stabil and non-ethanol fuel. Also started the generator EVERY month and ran it for 15 minutes. STILL gummed up after 3 months. Since I installed the shut-off and run it dry I have not had any problems.
SBrooks72
Explorer
Aug 04, 2014
It may sound trailer...but loosen the bolts on the pump and bang around with a hammer and loosen things up. It could be the pump is why I am saying this. Or check 12v connections.
SBrooks72
Explorer
Aug 04, 2014
Stabil