It looks like it has a cr250 motor in it...not like it will make a huge difference in runability. The reason I say I do not believe it is a 250r motoris it is a rearwards kick(like the banshee) while the 250r motor actually kicks forward. But realize that you will be pretty bored with the power of a 250r after riding the shee, unless the porting is wild the powerbands are pretty mild.
I honestly would not do it but I know I love my R but I am also running a pilot top end on it and it just screams,