What would you do - broken exhaust studs?

MattW

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With the help of Steptoe's howto and the clymer manual, I've just removed the left hand head off my 1100 in order to change a weeping head gasket.

In the process, two exhaust studs sheared (the inboard, 'middle' stud on each side). The other four studs just wound themselves out of the head, so easy to fit the new studs I've bought. I don't fancy digging the broken studs out myself, but there's a good engineering shop locally which can replace them.

But.....

In Steptoe's howto, he says it's quite possible to run an 1100 with one or even two studs broken on each side....

So if it were you, would you just refit the removed head with new gasket and ignore the one broken stud on each side. Or would you get the broken stud replaced on the head which is off the bike and then remove the good, non-leaking head to get that stud changed too?

Opinions gratefully received.

cheers
Matt
 
I know your pain....

I only had one stud stripped off from each head though, have been running around like it for 2 months now.....just Fire Gummed the exhaust back in.

No apparent leaks and all is well:thumb2
 
I am about to remove both my heads tomorrow to have all the studs removed, been putting it off for weeks, if you are going to keep the bike it depends on your character, some are happy with the fact it works and don't need the hassle or like me it will niggle me till i do something about it :rob
 
If it were my bike, I'd drill down the centre of what's left of the old stud, first with a fine drill, then with a larger one until it's opened out a bit. Keep doing this until you can see the threads inside the hole & clean those up with a thread tap. You can then just put a new stud into the hole.

I did both my cylinder heads in situ as the head gaskets weren't weeping & I'd no wish to remove the heads, just to replace sheared studs. It was very easy to do with a hand drill &, if you get it wrong & destroy the thread, just put a helicoil in.
 
I broke one of mine yesterday in fitting a full remus system. Ill drill it out as per pauls description.

Out of interest, why do people continue to use studs when they always seem to be going wrong? I have replaced studs for exhausts with standard bolts before with no issues. Unless im missing something special on the bmw? but if not ill just be fitting some stainless bolts to replace all the studs.
 
refit the exhaust. if you're content after a month or so that everythings fine and dandy. then you can make a final decision one way or the other at that point.
 
Thanks for the input everyone

I can feel a compromise coming on :)
I think I'll get the stud replaced in the head I've removed and I'll see how the other non leaky head does on two studs.

cheers
Matt
 
If it were my bike, I'd drill down the centre of what's left of the old stud, first with a fine drill, then with a larger one until it's opened out a bit. Keep doing this until you can see the threads inside the hole & clean those up with a thread tap. You can then just put a new stud into the hole.
QUOTE]

This works well, I've done it quite a few times on old Brits I've restored. You just have to take your time and make sure you get the first drill in as near to centre as you can. Start of with a magnifying glass and a centre punch for best results. In fact I think someone used to make a wee device specifically for the job.
 


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