Gasoline in Oil????

fighterpilota wrote:
Onan 4000 quits running. Check oil and it pours out. Smells like gasoline in it and really diluted. What is happening? Thanks

Carb float valve is stuck open. Rebuild the carb.

See Ninerbikes reply and also change oil and filter.

I have had lawnmowers do the same thing. I put a shut off valve between tank and carb and run for a few seconds before shutting off.

Thanks, have a mech. coming to look at it tomorrow. 1994 Callista Cove Class C and looks as if it is mounted on some sort of rack that slides out but don't see that it could hold the genny's weight. Any one know about such a mount?? Thanks

Why the mechanic ? They told you what was wrong.
Except it probably doesn't need a complete carb haulover, just drop the bowl, float, and blow out the needle valve, and push it back together, and install a fuel filter so it don't happen again. And don't forget to change the oil.
Oh yeah, if your float sunk. you'll need a new float :)

If it's a 'Microquiet' 4000, the carb _may_ be one of their non-rebuildable designs, with no parts available. You may have to buy a new carb ($250-350 for the whole thing). Take many pics from all angles before & during removal so you can be sure of getting the linkages right when you reinstall.

It's also possible that the choke is the issue. If the choke's not pulling off as it heats up, it's running rich all the time.

Jim, "Mo' coffee!"

Post a model/spec/serial number so we'll know exactly what you have. Onan made a whole lot of gensets through the years with a whole lot of changes.

If it has a mechanical fuel pump, I'd suspect a leaking diaphragm.

Yes, those came with a pull out generator mounting rack. Makes service a whole lot easier.