Exhaust SS BOLT removal

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wurlyvalve
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Bike owned: GK73a, TRX850, 955i, ZZR6D
Exhaust SS BOLT removal

Post by wurlyvalve » Thu May 18, 2017 9:12 am

Hello all,

My wifes' GSXR400 GK73a has a blowing exhaust gasket that I wish to replace. Also, I would love to change the oil and filter. Alas, it has a full Yoshi system fitted that makes the servicing look a little fun (not impossible) without removal first - and seeing as the gasket/s is/are leaking I would gladly kill two birds with one stone.

I'm an ex rally team mechanic so I'm not shy with tools, brutality and cursing at stuck parts.

The exhaust was bolted on (not by me) with (I think) M8 stainless steel cap head bolts. I've shown a couple of the easier to look at bolts my hex socket, extensions and ratchet etc but I can clearly see that they are twisting in their shank and will shear long before coming undone.

Has anybody else played this game and won?
One thought was to remove the fairing and spray the bolts with PB blast after every journey. But all of my previous experience has been if its seized the penetrating oils are too late to help. Plus gravity isn't helping me with that. Another thought was to get it hot, then using more heat localised and hope (ally heat and distortion not great for HG's). Or a less desirable course of action would be to shear them, remove exhaust and weld nuts onto the remaining exposed sections of shank and hope the heat from welding allows them to free up.
From there I'm getting despondent with thoughts like removing engine and replacing the cylinder head.

Cheers,
Glen.

moforockband
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Re: Exhaust SS BOLT removal

Post by moforockband » Thu May 18, 2017 3:15 pm

I've won ...and lost! I've snapped drill bits off/eezi outs etc etc! Spark eroder came to the rescue on them calamitys.
Turning the bolt too far weakens it, and it eventually snaps off. A good trick is to shock the thread by direct blow down the thread, then try localized heat.
An impact driver works well, and can stop the bolt from snapping off. You may have to take forks out though to get enough swing.
Be careful of the flanges around the head, it's really thin and weak.
It's patience that wins the day, not brute force on this wee job.

Nobbsie
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Re: Exhaust SS BOLT removal

Post by Nobbsie » Fri May 19, 2017 9:53 am

I have had really good results from "kroil" the oil that creeps, but not sure if you have it in the uk. Mofo is right patience is the key, I'd try some penitrating oil with a impact driver over a day or two of constant oil being added, if that does not work you could try drill them out if you know what your doing, masonry bit with LOTS of oil and speed is key here. But hey just my 2 cents others might not agree

kit352
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Re: Exhaust SS BOLT removal

Post by kit352 » Mon May 22, 2017 8:17 am

Soak the bolts with some penetrating oil for as many days as you can then start the bike for a minute or so to get some heat in the area then try to get them out after you shut it down. Use the heat to your advantage but dont let it get too hot.


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