i own a dr-z 125l (they are the same bike) and there are people around who will modiefy your exauset for around 100 dolars. also you could open up the air box by drilling lots of little holes under the seat, on the sides and at the front (not where mud can get in) and even though it has a fixed jet you can rais it buy putting a washer under it email me for more info dirt biks rock!!!