I have a Scag VTR that I just purchase a few months ago. It is a old Turff Runner with a 22 hp Kohler which I know is old. It has been running fine, I just replaced all filters, changed oil, battery and a few other things just because I think it had been sitting for a while. The time meter says 800 hours, but I sure that isn't correct. Any way it has been running fine and the other day I stopped mowing after a hour or so and went to lunch. When I came back it was hard to start and back fired a few times but did start. I mowed a few strips and it started back firing a bunch and lost power. I finally got where I couldn't keep it running. Any sugguestings ?