I have a friend riding an 01 250F *Yamaha and he has been running a White brothers exhaust that was for the 426 or 450 (I cant remember). He made a sleeve to stop the leak where the mid pipe joins the header. It rocks! with tons of top end (low end is noticeably different though). Is there any risk running the larger exhaust on my 03 250F? Not likely I will spend the $ for an exhaust that's not made for my bike I am just curious if others have tried this before..