Yes the yz 250 fit, have to cut the end of the pipe to pass in frame and mods the exit of engine bye cutting the pipe on the original weld rotate a little bit, do another cut below th first cut an rotate, the pipe need to be install from the left side of engine, then adjust, do 3 or 4 spot weld on the part of the pipe cute and aligned, try to remove from the bike, its will come out really tight but easy. weld all part if is come out from the frame.
i will try to post some picture of my setup this week.
sorry for my English i am from Quebec and speak French and my English is far far far away in my head
lol