My Onan Micro will start, run about ten minutes. and then shutdown. I recently had the carb replaced and tune up done. We went on the road and ran it to run the AC because of high heat. The gen ran about two hours and shut down. After about an hour we were able to restart it and it ran about an hour then shut down again. After that everytime we crank it the run time seems to be shorter each time. The last time was only about ten minutes. or so. It shuts down just like it was shut down with the switch, and not starved out for gas. Any suggestions? Thank you