The only way to get that bolt out to buy the special wrench or make on your self. You would have to grind down a 15mm wrench and then heat it and bend
it.
I would just buy one they are only like $15 from SBT.
hey if you get this...did you ever get that exhaust off? i tried removing my carbs first but have nearly stripped the 2 allen bolts on the rear carb. ugh...help please!