not familiar with the operation of the on board generator , any help would be great.
The Winnebago Operators manual (https://winnebagoind.com/resources/manuals/pdfs/Operator1985/85Winnebago-Itasca.pdf) says to refer to the Onan Generator Operators manual. On a Mini-Winnie, I suspect you have a Onan 4.0 BGE model generator. While we have the Operators manual for the different Onan Generators in the Members area, you need to get the model number information off the ID plate on the generator in order to select the correct manual. Different manual for different BGE model spec numbers.
As in, how to use it? When nothing is broken, you should be able to push the 'start' button, hold it while the generator cranks over, and release it when you hear it fire up. There should be a start button on the generator itself and hopefully on your dashboard too. Is that what you asked?
When it's running, there may be a light on the dash to show it's on and working.
Here's a guy starting his on youtube: https://www.youtube.com/watch?v=gxfhVk2YKLI
If it's not cranking over, or not running, or not making power even though it's running, or quits running as soon as you release the start button.... those are all problems that you'll need to look into with the manual for the generator. You should get the manual though just to keep up with maintenance.
Before trying to start it though make sure there's oil in it.
I haven't tried to start my generator yet ..the guy we got rv from showed us it turns over ..but he didn't try to start it ..he said may need to have old gas drained before try to start ..do you drain a fuel line before the filter ?
I would take the line off of the carburetor and put it in a can and then crank the generator over. That should activate the fuel pump and purge the old gas from the line and draw fresh gas from the vehicle gas tank as long as there is more than a quarter tank of gas in the vehicle. Once you have fresh gas it would be a good idea to change the filter soon but not absolutely necessary unless the gas will not pass through it. Hook the line back up and crank it again to get fresh gas in the generator and see if it will start. If not it may need to have the carburetor cleaned out.
Make and model number?
onan 3.0rv genset
does this mean anything?
If your Generator looks like this
(http://i288.photobucket.com/albums/ll189/LeeannS24/OnanAJ.jpg)
Then here is the operators manual (http://www.twinslan.net/~n0nas/manuals/onan/924-0122%20Onan%203KW%20AJ%20(spec%20S)%20RV%20Genset%20Operator%27s%20manual%20(03-1979).pdf)