Onan gen set forum.....Can't seem to find it?

[Isaac-1]

If you really want to find out more than you ever thought there was to know about Onan generators try posting over at the SmokStak board in the Onan generator forum, this includes not only RV units, but everything up through the 300-500 KW diesels.

[SteveinMB]

I had this problem with the Onan 4K generator in my 1996 Southwind 30. When I got this coach the generator had about 123 hours on it. Not bad for an almost 20 year old coach. Checked the air filter and tried using spray carb cleaner. I thought that the fuel filter to carb hose was collapsing, also tried WD-40. None of these attempts worked. Since I owned and serviced motorcycles and outboard motors in my youth I decided to remove the carb bowl. The interior of this bowl was covered in dead fuel varnish. The fuel cutoff switch was stuck open. I poured a small amount of SeaFoam ( wear proper gloves) and replaced the bowl. A couple of days later I attempted to start the generator at the unit. The generator started but would not run unless I manually operated the throttle. Doing additional research it became apparent that the fuel filter was also clogged up with old fuel varnish. My generator is 4KY which has the fuel filter buried in the chassis and is difficult to get at and requires removal of some of the electrical wiring. I went to Walmart and bought 4 cans of the SeaFoam product to add to the gas. About a week after I added the SeaFoam and during an engine run, the generator finally started. The generator would not run at a constant RPM but does now. I have not needed to continue using the SeaFoam. The generator still has the original fuel filter with a 160 hours. I will change out this filter before my next trip.

[lonfu]

Ok, so, I'm a good mechanic, but my buddy who is one of those guys who can lay his hands on the engine and tell you that it has a over sized bearing in cylinder 6 walked me through Gen Sets. Clearly it has a speed governor that is controlled by the voltage. My friend Mark is one of those guys that currently is a BMW master mechanic but has built and worked on everything that uses liquid fuel. So, first thing he tells me is that Onan builds their gen sets for old retired folks that know nothing about gen sets other than to push the start button and check the oil..........

Well, I pulled the 120v plug, fired up the gen set and didn't touch the throttle. Fired up the AC unit and the micro wave. Nothing.... They worked perfectly, gen set didn't even sound like it was straining. The old style hour meter even works, makes a loud clicking sound but works. It reads 264 hours. When it was running under load it smelled like it was running rich, but it ran

When I inspected the oil it clearly needs to be changed. So, guess that is another thing to do on my "honeydo list".

I like the seafoam idea. Hmmmm any one tried some lucas oil gas treatment? I have some of that hanging around. Guess it wouldn't be a bad idea to throw some of that in the tank.

thanks guys for the suggestions and information.

Moral of the story: Mess with the butterfly plate

[lonfu]

done and thank you!

Originally Posted by narampa

Send me a private message with your email.
I will send you a PDF Service Manual and a PDF Parts Manual.
You might want to send me the model # also.

[SteveinMB]

I use the Lucas product because I use the cheapest regular I can find. The Ford 460 runs fine on the stuff and I think it helps keep the fuel sweet when the coach is stored. By the way, my generator's speed governor is like constant speed control used in a lawn mower engine.

[Charlie 5320]

Originally Posted by SteveinMB

I use the Lucas product because I use the cheapest regular I can find. The Ford 460 runs fine on the stuff and I think it helps keep the fuel sweet when the coach is stored. By the way, my generator's speed governor is like constant speed control used in a lawn mower engine.

Some onans use a mechanical governor and some use an electronic governor. Every RV generac I've seen use a mechanical governor. Most all generacs used in RVs are belt drive, where only some onans are belt drive.

[lonfu]

Originally Posted by narampa

Send me a private message with your email.
I will send you a PDF Service Manual and a PDF Parts Manual.
You might want to send me the model # also.

thanks for the manuals, they are great.... Put me right to sleep!! No really, thank you!

[lonfu]

Originally Posted by Charlie 5320

Some onans use a mechanical governor and some use an electronic governor. Every RV generac I've seen use a mechanical governor. Most all generacs used in RVs are belt drive, where only some onans are belt drive.

Charlie, you are right, some fool mechanic was pulling on throttle thinking he could clear some carbon out of the top end. Duh.... Other than smelling rich, it runs perfectly....

[draboo]

This forum will set you straight with all things Onan: https://www.smokstak.com/forum/forumdisplay.php?f=1