Onan Propane Generator

[CarlGeo]

I have a 6300 Onan propane generator with approximately 650 hours. Recently I started it and it ran for about 30 seconds then quit. Tried repeatedly to start, but did not. Came back about an hour later and tried to start and it started and ran fine.
In the next few weeks it started and ran fine.
Today I started it and it again ran for only about 30 seconds and stopped. Tried to restart and it did not start.

Any ideas on what the problems is?

Thanks
CarlGeo

[wolfe10]

Correct. The longer hydrocarbon "contaminants" do not boil (turn to vapor) at the same low/ambient temperatures as propane. So the vapor is far more "pure".

And there are many of us who have converted liquid LP generators to run on high pressure vapor (before house regulator). Been running my Liquid LP Onan like that for many years.

And, if you do overhaul to on-generator propane regulator to remove the contaminant, be sure to get the special high temp/silicone gasket set.

[wny_pat1]

Berner2 wrote:
When I got it back I swapped it from the liquid side of the tank to the vapor port. Works like a champ now. Hopefully you don't have this same problem.

The liquid to vapor swap is supposed to eliminate the gumming up. Just a thought.

Excellent point. All the following is in layman terms, so please bare with me. Many of the older generators were set up to run off the liquid side of the tank, and had a vaporizer regulator at the generator. The newer ones are set up to run on vapor. ASME tanks found mounted in motorhomes have a liquid discharge valve and a vapor discharge valve. LP-gas inside a container is in two states of matter, liquid and vapor. The liquid portion of a container is in the bottom area and the vapor is in the upper area above the liquid. Contaminants in the propane will settle to the bottom liquid portion of the tank. If the generator is drawing off the bottom liquid side of the tank, the contaminates can enter into the line feeding the generator and gunk up in the generators LP regulator/vaporizor, requiring it to be re-built or replaced. Much less likely when running off the vapor side of the tank.

And some LP shops and Generator shops will tell you that you can not do this. Find one who will do it.

[Berner2]

I had a similar problem with mine. Sometimes fire right up and others it wouldn't start at all. The exhaust had a strong propane smell also. Turned out to be a fuel problem, gummed up and I also believe a leaky line at the generator. Had it fixed at the Onan place $$$$. Mine isn't on a slide it has to come out the bottom. When I got it back I swapped it from the liquid side of the tank to the vapor port. Works like a champ now. Hopefully you don't have this same problem.

The liquid to vapor swap is supposed to eliminate the gumming up. Just a thought.

[CarlGeo]

Just an update. Waited about 2 hours from last start attempt, and unit started just fine and is running with both A/C units running.
Thanks for those who replied so far. I know the oil level is OK because it was just changed and filled at last exercise and 30 min. run. Auto transfer switch? Will check into that if condition persists.

Thanks
CarlGeo

[vegasfoodguy]

Check the oil, Will not run if low on oil.

Terry

[darsben]

Some ONAN generators shut down automatically if they do not sense a load. The automatic transfer switch if you have one may be defective. That is what happened to my Jenny until I changed out the transfer switch.

Sometimes it worked sometimes it did not. How I found out was by tapping on the transfer switch when it would not work