My buddy got a load, a large load of millings and I told him I would spread it. About an hour in, I shut it off to talk and it backfired. I slowed it down before shutting it off, but I have to admit not as much as I should have. It has never backfired, so I thought that was odd. I went to start it, and after half a turn it locked. I was able to turn it back some, and hit the key, same thing. This time, I could not get it to turn either way. I got the starter gear disengaged, so it is not the starter. I took the plugs out thinking maybe the needle valve got stuck and it hydrolocked, nothing. We wound up getting somebody else’s Kubota. I know one of the terramite engines is prone to blowing up... which one is it? I have the Kohler magnum 20. Any ideas?