Honda-SOHC
SOHC.co.uk Forums => CB750 => Topic started by: ShaunJ on January 15, 2014, 02:27:59 PM
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One of the exhaust studs sheared off on my K7 when I was attempting to remove it. Four came out with the stud three actually undid as they should. It is the outer stud on cylinder 4 that sheared so at least it is easy to get to. It sheared with only about 2 mm left protruding so there isn't, enough left to get a grip on. Can anyone offer advice on the best way to fix this.
I was also considering removing the centre stand to get it powder coated. I am now wondering whether it would be easier just to paint it on the bike instead. Do the centre stands usually come off easily or is it a big hammer and blow torch job.
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Hi,
You could try putting a nut over the broken stud and getting them welded together,there is the chance that with the heat from welding being directly on the stud it may loosen it enough for the nut to turn it out, overnight soaking with penetrating oil would also help
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Hi Shaun, I've just had to deal with 2 sheared off studs 1 sheared off just below the surface and one similar to yours, I ended up drilling mine out and helicoiling them, I had never done helicoiling before and found it very easy to do :)
your centre stand should come off easyish depends when it was last off ?, undo the 2 clamp bolts, then take the split pin out of your pivot tube and tap it out,
if its not been off in a while it may need heat or wd40 or both to move it ;) cheers Mick.
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Thanks for the advice. Are these broken stud removal gadgets worth a try? Looks like you drill a hole in the stud and insert the gadget which has a anti-clockwise thread. Not sure if it is too small to be able to do this. Obviously if it breaks in the hole the problem is made a lot worse so there is a risk.
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Dont go near it with a stud extractor, it will break off.
As said above, a nut welded on is the way to go, If you don't have the facility, and can get it to Aston M1 J31 I can help.
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Many thanks for the offer of help. Unfortunately I have no means of moving the bike at the moment. I know someone at a local engineering company who has access to welding equipment so I will make contact and see what they say.
Shaun
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Hi Shaun
My centre stand was a nightmare, I had to cut though the centre fixing to get it off, then nothing would get the fixing out the stand (even oxy heat would not budge it) but when it painted properly, it will be much better and harder wearing. I would suggest trying a bit of heat and try to remove if poss, if not, then paint it on.
John
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re.exhaust stud .....I had one shear off when I had a cb750 engine in bits.tried the stud extractor method....useless....that snapped off and the guy at an engineering firm couldn't drill it out because the extractor was too hard.i was recommended having it 'spark eroded' at a nearby company(Derbyshire).they made a superb job..the original threads were left undamaged and they only charged me 20 quid....well happy....
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Oddjobs method worked for me!
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yep same here done the same as oddjob on swinging arm bushes ;)
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Yep Done all of that remembered again by the responses
Well done guys
Cheers
Bitsa
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I was lucky enough to have a bit more stud protruding than you have and was able to use a socket type stud extractor that went over the stud.
I recommend whatever method you use that the overnight soak in releasing fluid and the application of heat as already mentioned as well. In my experience you tend to screw things up royally if you don't take them seriously so the more methods you can apply at the same time the better!
I have had some success with the reverse thread stud extractors ( + heat + releasing fluid ) but as mentioned above they are so hardened they are very brittle and break very easily and are a s*d to get out once they have.
Overall +1 on the weld something to it!
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Thanks for all the help and advice.
I had it soaking in WD40 for a week. Tried for three hours to weld something to the stud but each time it just snapped a bit more of the stud off. Gave up with that method and ended up drilling it out. Managed to preserve most of the threads by picking the bits of the stud out of the hole. I am not sure that it was a "stud" it looked like a piece of threaded bar which had become extremely brittle. It originally sheared under very little pressure so either it was substandard material or it had been "cooked" by the exhaust temperature.
The good news was that the main stand was very easy to get off and has now been powder coated and refitted. It is looking good.
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Hi Shaun,
Glad you're sorted---Ken