Page 1 of 2
Advice please: removal of broken exhaust stud
Posted: Wed Jan 27, 2016 9:35 am
by Henners
An exhaust stud on my 1100S snapped at the base of the domed nut when I tried to take the pipes off yesterday for polishing.
I have replacements however it's steel into alloy so should I heat the head around the stud? Penetrating oil required? I guess it's a left hand thread.
Your wisdom please ~ Tom
Posted: Wed Jan 27, 2016 11:57 am
by ceepee
why would it be a left hand thread ?
Posted: Wed Jan 27, 2016 1:09 pm
by beachcomber
Normal RH thread - we've had 6 of the buggers break / already broken on our project engines.
Replace with brass or phosphor bronze to eliminate any future probs.
Posted: Wed Jan 27, 2016 1:42 pm
by JamesL
beachcomber wrote: Replace with brass or phosphor bronze to eliminate any future probs.
There's a thought. Will brass take the torque OK (I know it's not much)? And presumably smother in copper grease when reassembling etc.
At some stage I'm going to have to remove the rusted on header bolts for the GS. I doubt they've ever been moved since new and so far I've failed to shift them so I've let the sleeping dog lie. Is it worth having a go, or do I simply hand it over to a professional?
With the 100RS 5 minutes of careful hacksawing each side and bob's your auntie!
Posted: Wed Jan 27, 2016 4:16 pm
by Herb
I have seen so many people screw up castings trying to remove broken studs. Its not too hard with the right tools and technique to remedy, but if in doubt take it to a professional.
Posted: Wed Jan 27, 2016 5:25 pm
by Henners
Herb wrote:I have seen so many people screw up castings trying to remove broken studs. Its not too hard with the right tools and technique to remedy, but if in doubt take it to a professional.
Fair comment Herb however that means removing the cylinder head and I don't have the facilities to do that, so looking for tips and advice.
Posted: Wed Jan 27, 2016 5:38 pm
by ianbcr
you could try these, work well on normal rusted or broken bolts.
https://www.machinemart.co.uk/p/cht526- ... tractor-s/
Posted: Wed Jan 27, 2016 6:09 pm
by Henners
Thanks Ian

Re: Advice please: removal of broken exhaust stud
Posted: Wed Jan 27, 2016 7:37 pm
by nab 301
Henners wrote:.
I have replacements however it's steel into alloy so should I heat the head around the stud? Penetrating oil required? I guess it's a left hand thread.
Your wisdom please ~ Tom
Luckily not happened to me yet..... all the advice I can offer is what I read on here and uk gser. Heat the stud ,(it'll need to be very hot) when it cools and contracts it may help break any corrosion. . Heating the head around the stud may help also. If you're removing any more dome nuts I'd drill the front of them first to allow you to spray penetrating oil / diesel into the threads and then heat the nut .
Posted: Wed Jan 27, 2016 7:38 pm
by Boxadog 2000
Dont go near that type of stud extractor they are rubbish.
You could weld a nut to the remaining bit of stud and use liberal amounts of plus gas not wd40.
I have mainly found it to be ahead off job though
Posted: Wed Jan 27, 2016 7:51 pm
by Herb
Henners wrote:Herb wrote:I have seen so many people screw up castings trying to remove broken studs. Its not too hard with the right tools and technique to remedy, but if in doubt take it to a professional.
Fair comment Herb however that means removing the cylinder head and I don't have the facilities to do that, so looking for tips and advice.
Sorry Henners. My quote was directed to JamesL. He was asking whether to have ago himself or take his bike to a professional.
Posted: Wed Jan 27, 2016 10:04 pm
by dysondiver
oxy acet , or one of those high tech mag induction heaters , if your rich a few heat and cool cycles , sheilding the head as moch as you can , then a good fast heat , and remove with a good sharp pair of vise grips , then use tungsten dry lube on re assembly is the only way ive found to work ,,, hth
Posted: Wed Jan 27, 2016 10:06 pm
by dysondiver
lol ,,, eleven pounds for a stud extractor set ,,, dont bother ,, just tear up a tenner , and throw it away , and your still a quid up.
Posted: Thu Jan 28, 2016 1:54 am
by boxerscott
Boxadog 2000 wrote:Dont go near that type of stud extractor they are rubbish.
You could weld a nut to the remaining bit of stud and use liberal amounts of plus gas not wd40.
I have mainly found it to be ahead off job though
Agree. Pro help needed here. LH thread... NOT. Leftie loosey, Rightie tighty

Posted: Thu Jan 28, 2016 9:32 am
by beachcomber
Every one of the broken studs we had to replace required head off, careful drilling and tapping.
In the good old days many OEM manifold flanges where attached using brass or phosphur bronze [ best ] nuts. Brass is OK for this application, not sure where you'd get pb nuts these days.
Remember, stainless is NOT a friend of alloy ! A pal of mine used stainless allen bolts on his Kay to eliminate any future seizing problems of the exhuast studs / nuts - good luck with that.