I picked up an old Craftsman riding mower, 13.5hp Turbo Cool engine and 42" cut, for FREE. I removed the cutting deck and want to turn this into a little fun machine for me and the boy. I know there are mechanically inclined members here. What little tweeks can I do to get a little more speed out of this thing. It is a six speed. Has anyone pimped a mower? He ran a whole tank of gas out of it today.