Classic Winnebagos & Vintage RVs

Ok Im back with another question.  Im going to go down and get the Harbor Freight generator tonight.  Since I don't have time to get this one going.  But I need to figure out what is up with this Generac NP36 generator.  It is running.   It starts right up no problem.  Fresh oil and everything.  It even idles properly when its started.  After running for about 30 seconds if that it idles down very low.  Too log to power the RV.  Nothing work.  I did test on portable generator and everything works as its supposed to.  This onboard generator is just not running fast enough to produce power to power the RV.  Any idea where I might start? 

Side note it is proving difficult to take this to a shop.  The shops I call just keep sending me somewhere else.  Im at a loss.

Thanks for all your help.

That's gotta be really frustrating.  It runs fine, but won't idle up enough to do any good!
Do you have a manual for this?  Having one is obviously a big plus.
If not, we have tons of manuals on generators and a lot more in the member area.  Full member upgrade is only 5 bucks... and the best 5 buck you'll ever spend.

I do have all the manuals for the RV.  Including the generator.  We have a trip planned so Im going to use the portable generator as a temporary then next week I made and appointment at United RV.  They said they do work on this generator.  So hopefully they can figure out whats going on.

 :) :)ThmbUp