I have an 08 brute force 750i. It smokes alot and uses alot of gas.like i went out and rode 18 miles and it was empty. I have had to several dealers and the only thing one of them could find wrong with it was there was carbon on the valves and they put ring free in it and said it should clear up the problem but it is still doing it.im at my wits end with it does anyone know what could be wrong with it. could it be the cpu.