Barthmobile Portal
Onan Generator Problems

This topic can be found at:
https://www.barthmobile.com/eve/forums/a/tpc/f/3631087061/m/8483999197

09-17-2018, 06:25 AM
Danny Z
Onan Generator Problems
A while back I fired up the Onan for it's regular running, and after running fairly well for a minute or so it started missing. I let it run for a while and it just got worse, so I throttled it up by hand and it started belching blue-white smoke, then black smoke for a second before it died. I didn't have time to do any checking right then so I put it of for several days. Started it up and it ran but very rough and still smoking white very badly. When I twisted the oil cap it overflowed and had a lot of gas in it. I drained it and pulled the filter, then pulled the carburetor. My work partner is a pretty good small carb man so I gave it to him and he tore it down and gave it a good cleaning. He said the float bowl had chunks of crap and was filthy. Installed the clean carb, new oil and filter,and new spark plugs, and she fired right up. After a little adjusting on the jet, she seamed to be happy with seated, then backed out about 1 and 1/2 turns. A little blue smoke for a minute or so then clean exhaust. Turned on the AC for a load, ran perfect, checked the voltage at an outlet, 118v, let it run for half an hour and she purrs like a kitten. Still going to install a new in-line fuel filter and shut off valve, and will shut of fuel and run out of gas before hitting the road from now on, but pretty sure I've taken care of the problem.

Hope this helps out someone in the future.


79 Barth Classic
09-17-2018, 03:44 PM
ccctimtation
Danny, I think your story convinces me to add an inline filter to my genny. The fuel pick-up is ~2/3 down into the stb tank and I have never had a problem and the hour meter should be around 3000 but those passages are certainly small and easily blocked.
Tim
09-17-2018, 07:21 PM
Danny Z
I think the problem was a stuck float, allowing gas to flow into the intake when the engine wasn't running, and flooding the crankcase. Hoping Steve or other geniuses can clarify.


79 Barth Classic
09-17-2018, 07:48 PM
Steve VW
quote:
Originally posted by Danny Z:
I think the problem was a stuck float, allowing gas to flow into the intake when the engine wasn't running, and flooding the crankcase. Hoping Steve or other geniuses can clarify.


Bingo! Same thing happened to me on a snowblower. (You remember, for shoveling the "s") head bang

Should be good now.


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp