ok, so im just going to buy a used go kart and fix it up. i have it, ive gotten bigger tires, new spark plug, new muffler(straight pipe), and a few others. the only thing i need/want to do is change the gear ratio. i dont know what gear ratio is best. i am mainly using it off road, flat. no big hills or anything, and a little on road, not that much. i want a good top speed. no more than 40-45, but no less than 30-35, and a good acceleration, but not to the point im spinning out, just give me a little kick..any pointers?!?! thanks..