iirc they're m8 x 1.25. I had to replace both studs in the head of the engine I have in now but they were just studs from a big box of assorted exhaust studs rather than ones I bought specifically.
Removing broken-off studs is likely to be very difficult or impossible with the engine in the bike. I had a nightmare with mine and that was with the cylinder head on a workbench. Assuming your studs are not broken - proceed very cautiously and with a lot of WD40 (pref liberally soaked the night before).
Imho studs > bolts for the exhaust for the simple reason that you can use non-seizing nuts (e.g. copper or brass exhaust nuts) on a steel stud which will not corrode in place or snap the stud on removal..thus avoiding the situation you find yourself in now.
Removing broken-off studs is likely to be very difficult or impossible with the engine in the bike. I had a nightmare with mine and that was with the cylinder head on a workbench. Assuming your studs are not broken - proceed very cautiously and with a lot of WD40 (pref liberally soaked the night before).
Imho studs > bolts for the exhaust for the simple reason that you can use non-seizing nuts (e.g. copper or brass exhaust nuts) on a steel stud which will not corrode in place or snap the stud on removal..thus avoiding the situation you find yourself in now.
