Onan generator issue..

[vdubee]

Ok guys, question on my generator. I have a 2012 Greyhawk 31DS that I purchased recently. We're totally in love with the unit!! However, I do have a small issue with the generator. The generator is a RV QG 4000. I can crank it up first thing and it will run fine. However, somewhere between 30 minutes and 3 hours usually, it will just surge a couple of times and die. It won't crank again for a while. When it does crank again, it can run for another 30 minutes or up to 3 hours. Really weird!! I have changed the oil and air filter. Considering also doing the fuel filter. Any other recommendations?? Thanks in advance for any help!!

[TX_Arvee]

Just wondering what your fuel situation is when it shuts off? It will shutdown when your fuel tank is at 1/4. Something may be a problem in this system causing it to quit prematurely.

[vdubee]

Originally Posted by TX_Arvee

Just wondering what your fuel situation is when it shuts off? It will shutdown when your fuel tank is at 1/4. Something may be a problem in this system causing it to quit prematurely.

TX, the fuel tank shows slightly over 1/2 full.

[Jeff61]

Originally Posted by vdubee

Ok guys, question on my generator. I have a 2012 Greyhawk 31DS that I purchased recently. We're totally in love with the unit!! However, I do have a small issue with the generator. The generator is a RV QG 4000. I can crank it up first thing and it will run fine. However, somewhere between 30 minutes and 3 hours usually, it will just surge a couple of times and die. It won't crank again for a while. When it does crank again, it can run for another 30 minutes or up to 3 hours. Really weird!! I have changed the oil and air filter. Considering also doing the fuel filter. Any other recommendations?? Thanks in advance for any help!!

This sounds like you have an ignition fault that occurs after the engine is hot. When it is cold, engine will start up and repeat the fault. Unless you are versed in small engine troubleshooting and have the tools to do so. It may be an ignition grounds fault or defective CDI. It needs to be determined, that when the engine dies do you still have a spark? Because, you need to eliminate fuel or ignition as the cause. It will be one or the other. If your first guess was to change the oil and filters... Consult a small engine/ generator specialist and stay out of trouble

[vdubee]

Originally Posted by Jeff61

This sounds like you have an ignition fault that occurs after the engine is hot. When it is cold, engine will start up and repeat the fault. Unless you are versed in small engine troubleshooting and have the tools to do so. It may be an ignition grounds fault or defective CDI. It needs to be determined, that when the engine dies do you still have a spark? Because, you need to eliminate fuel or ignition as the cause. It will be one or the other. If your first guess was to change the oil and filters... Consult a small engine/ generator specialist and stay out of trouble

Jeff, I understand what you're saying!! The main reason I went with oil and filters, besides not knowing when the last time they were changed, was because I know on the onan's when the oil gets old sometimes the unit will shut down due to low oil pressure. I plan on troubleshooting before I take it into a service center.

[LI-Camper]

My Onan would behave just like yours. Only it would quit after a half hour. There is no low oil sensor in my generator. The electric fuel pump would quit when it got hot. Mine is a KY series Onan 4000 W MicroQuiet. The new pump cost about $80. It is located on the left side and is not too tricky to replace. Maybe the generator fault codes will help you solve your problem. Check your manual.

[cb1000rider]

The fuel pump on my 5500 Onan had a cross reference to a part that was about 25% of the price. See if you can chase it down. I've had no problems with the Onan 4000.

I agree - it sounds like fuel starvation due to fuel line vaporization and/or the fuel pump quitting. I did a few things to address this:
1) Insulated the fuel lines.
2) Insulated the fuel pump.

If you're mechanically inclined, pull the fuel line after it quits and try priming the pump into a container. See if you've got fuel.

And indication that this is a "Fuel" issue is that it's more likely to happen sooner during hot weather.

[cloudbuster]

This sounds exactly like mine. Fuel pump was the problem.