What's involved to swap my Generac to Onan?

I had a generac primepact 50G, 4800 watt gas generator and absolutely hated it. Worst generator i've ever owned. There were tons of problems with it. First one was the arm that controls the engine speed broke(made of very thin steel)while I was on a week-long camping trip, boondocking and had no power for most of the trip. Made the trip miserable. So I welded it back together and away I went. Then, the carburetor started leaking from the float bowl rubber gasket. Guess what, can't buy parts for the carburetor. But you can buy a new carburetor for lots of money. Also, this genny was VERY hard to start all the time. Crank, crank, crank, and sometimes crank some more before it would actually start. It was all dialed in and tuned up, just a steaming pile of junk. All this with a full tank of gas, clean filters, topped up oil, etc. Never again.