We've got a few U800s and C800s that have had an issues with starting. They start right up initially but quit after a second. Do the same thing again and it quits 1/2 the time. The other 1/2 the time it will start and run rough. Like it's running on 1 cylinder. You can rev it up and it feels like that cyl comes and goes. Most of the machines run better on there own when they warm up but one runs rough even when warm. Any body else have anything similar happen? Thanks