RV Repair: Generac Genrator, tom loveless, general mechanic

Question
I had my gerator worked on by general mechanic when it would not start.  Now is does start, but after a while it starts running kindof rough---running then cutting back, them ruening full capacity.  It is running "up and down" and catches up, then back down.
Main problem is that when it is running nothing inside the RV works on AC.  Have tried letting it run for a while and then trying various appliances like fridge, microwabe, AC, etc. but nothing comes on at any point.
What do I need to check or replace, or possible troubleshooting areas.

Thank you for your time and help,
Tom Loveless
1110 Cleveland Avenue
Glasgow, KY 42141
Home Phone:  (270-651-3619)

Answer
Well first you need to know if you have a transfer switch and see if it works. If not you will need to find where to plug it in to get the power from the generator. Usually when the generator is on line it stays pretty even running except when a load is put on it. Check for output from the generator and then power at the main panel in the coach. Check for the circuit breakers on the generator as well. A good way to make sure the generator works right is to always have it serviced by a shop that repairs generators, and for whatever brand you have.