Onan 4000 Starts great then quits....

Appreciate the feedback. I haven't been on the boards for a while. The answer was the carburetor was malfunctioning. I had a new one installed and I do have to manually manipulate the choke but it starts and runs smoothly now. Thanks

Of course another thought occurred. The circuit breakers on the Genny could be popped. This will cause a shutdown They are sometimes hidden on the rear of the Genny

I tried to start it again and noticed the rpm speed once started seemed excessive. I tried manipulating the valve to the rear of the butterfly valve. Will also check out the fuel filter suggestions... Will keep any progress posted. Thanks for all the helpful suggestions.

Had a similar issue. Replace fuel filter and pump but the solution may surprise you. Check out my post.

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28927795.cfm

Some of these "fix the gen myself" stories turn out good but a LOT of them don't.

You may spend a lot of time and money and still not have it run right.

I have found the dealer in my area to be competent and fair price wise.
Onan is a division of Cummins Diesel.

I had the same problem when I took delivery of our unit during the walk thru. Ended up being a fuel filter issue. They replaced it and have not had any trouble since.

Good points so far. If the relay does respond to tapping it could be that the contact tips are worn or the connector plug is dirty. You could also check the oil pressure shut down switch and check all the connections or circuit board connectors. Sometimes removing and replacing a connector will establish a good connection. Do one thing at a time and check results.

They do shut down if the relay switch does not engage.
10 seconds is about the time for the go, no go on the switch engaging. It may be stuck in the shore power position.
If you can find the automatic relay switch. Sometimes it is hidden behind the circuit breaker panel. give it a couple of good raps with a rubber mallet (hammer if you do not have a mallet). Start genny see if that cures problem.
I have had to move the butterfly on mine for 2 years now but only sometimes.

Often, you'll get a crack in your fuel line and it will draw air. A simple test is to run a short fuel line from the carb to a gas can and see if the generator starts and runs.