We have had the carbs apart to inspect them. Everything checked out and is working correctly. The thing will run alright for about 10 seconds but after that the thing is scorching hot and 10 seconds isnt an exageration. I don't really know much about these engines, so i dont even know where to start with it. We were told by a guy it could be the water pump but why would it only backfire and run like shiz on one side only? We took the cover off the pump to check anyways it appears to be working but the plastic impeller looks like its rubbing on the outside cover and the housing is this normal? Should we take the cover off and see what it looks like inside it, as you can't see much from the outside. It was running great and then all of a sudden this happend trail riding. The plugs looked good nice tan color to them both. Any info is appreciated.