yeah!!! just watch out u using good tires, cause i swa a pic once and someone had ripped open the thottle of a cr500 and it just toe the tie apart, i think this mite be the case if you get a 250 two-bager.
but i know t.p (travis pastrana) has one only it a 50 with a 125 engine in i I THINK i think i saw it was a comment on a youtube vid.