I am building a kart for the kids one is 11 the other is 9. bought a frame, had a 6 hp tecumseh, i am putting a 12 tooth and 60 tooth sprocket on. How fast should I expect to run? I also have a live axle should i install or should i keep the existing single drive we will be riding gravel roads and such. 1 more thing there is no throttle cable and no brackets have pedal on kart but nothing else what to do????????