What happens if an exhaust mounting stud snaps off?

[Athame57]

I took my bike in today to have the oil pump seals changed and get a set of genuine Honda exhaust mounting studs fitted to replace the rust prone homemade junk currently in place.
The mechanic had to tell me he would only try so hard if any are very stubborn, lest they snap off. If that happened where would I stand though?

[K2-K6]

If they've informed you of the risks, then rectification would in all logic be at your cost, should they snap any.

Fixing it ... down to competency within that business as to how they approach this.

Most assured outcome would likey involve the head off and to a machine shop to mount on a milling machine, then to machine the broken part out   ( especially if stuck with nothing protruding) to not balls up the head casting.

A friend, when these were contemporary engines, ran a jig on milling machine to do this and to machine the spark plug holes, especially two centre one's, in repairing them. All his customers were bike shops that farmed this out to him.

Difficult decision to go ahead or not, they can easily go wrong and they are right to warn you of this.

May be lucky if they've originally been put in with coppaslip or similar. 

[McCabe-Thiele (Ted)]

I took my bike in today to have the oil pump seals changed and get a set of genuine Honda exhaust mounting studs fitted to replace the rust prone homemade junk currently in place.
The mechanic had to tell me he would only try so hard if any are very stubborn, lest they snap off. If that happened where would I stand though?

A local engineering firm Helicoiled four of my head studs on the 500  I snapped three , removed four, left one for them - one is fractionally out of alignment so the new Delkevic clamps would not fit one pair of studs.

I used my originals that have more clearance. They skimmed my head as well - they did a brilliant job removing only a few thou to get rid of a couple of marks near where the head gasket seals the bores leaving a mirror type finish. It cost more than I expected tbh.

[Spitfire]

I came across this when I was stripping down the F1 to start the rebuild, at first there was a broken stub visible about 1 inch, so I tried heat, penetrating oil, freezing stuff all to no avail.
I then used a roller type extracter which broke the stud revealing that nothing at all had penetrated
So it was head off and away to a machine shop, this did not bother me too much as I then could check the top end as the bike had been in storage for 10 years, I did find a stuck piston ring so it was worth it.


Cheers

Dennis