Broken exhaust stud

[Snake the Sniper]

Evening folks.
Not being a regular in this part of PH, I'm not sure if this is the right place to post this or not, but here we go anyway. Went round a mate's house this evening to help remove his exhaust manifold as he wishes to clean/polish it up a bit. Nowt unusual with that, until I hear a thud behind me as he snaps an exhaust stud off. All the others have come out just fine, and this one is the left hand side stud on a hornet. Which means the frame is a bit in the way. I've already sprayed it with penetrating fluid, and will go back tomorrow to finish attacking it, but are there any easy/helpful tricks for doing this with the engine in the frame still? I'd like to keep disassembly to a minimum, as it's probably me that'll have to out it back together! I'm thinking mole grips on what's left of the stud, as there's no thread left showing, if not, slot the end and use a big screwdriver, and failing that, drill and re-tap. Any objections to that plan as I've not had to work on bikes before!

[Benni]

If what´s left of the stud is long enough for 2 nuts,
why not put an outside thread on it,
then two nuts jammed against each other should provide more torque
when a wrench is applied than a mole grip.
And, yes, lots of penetrating oil.
Good luck,
Benni

[Rubin215]

Heat; plenty of heat.

Oxy-acetylene is best, but plumbers blowtorch will do (hairdryer won't).
Heat up the broken stud itsef and let it transfer along and into the head; just don't melt it...

Plumbers flexible heat mat will also stop you scorching the frame, but your fingers are your own responsibility!

[rsv gone!]

I had a stud break on my old Sierra exhaust manifold. I tried heating, penetrating fluid and stud extractors. Never did shift it!