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Started tinkering with my new acquisition and one of the first jobs was to take off the corroded exhaust. You guessed it......two exhaust studs were seized and sheared off flush to the cylinder port.

Any pearls of wisdom or tricks to get them out. Drilling and re-tapping is the solution I guess but is it do-able with DIY tools.

Thanks chaps.

sorry to be the bringer of bad news but if they are sheared off flush its not a diy job at home. you can either get a local precision eng shop to drill out the old stud and hopefully run a tap of the original size down the hole, picking up the original threads, or use a spark eroder to remove the stud.

generally old studs need plenty of plus gas penetrating fluid left on for a couple of days, build a plasticine "resevevoir" round the stud and fill it up, then use a blowtorch to heat up the stud/nut and gently try to undo. oh empty the fluid first.

when you reassemble use copper grease.

siezed studs are a nightmare speccialy steel into ally.

Thanks Scorpio - I didn't think it would be a diy job.

Cheers,

You could always attempt my tried and tested method:-

pilot drill the stud, then use a bigger drill to open up the hole a bit, then use an easy out or similar, which will break off flush and is impossible to drill as it's harder than Vinnie Jones.

Then take it to an engineer like you should have done in the 1st place, makes him laugh though.

Good news..... The one that I thought had broken off flush the cyclinder still had about 3/8 of an inch showing once I got the exhaust clamp off (forgot mention that yesterday) after sooking it for 24 hours in penetraing oil there was enough to file two flat edges and I managed to ease it out with a pair of mole grips. The inner thread was very clean with only a very small amount of corrosion where the stud met the cyclinder. I think the stud broke where the rust had eaten away near the bolt.


Huge sigh of relief.... but one learns very quickly.

I did do this on my CG125, with DIY tools - just went very easy with the drill, started with a small bit and gradually used a bigger bit - eventually, the stud started collapsing on itself, so ran a tap through it to clear the threads.

Should point out that this was on a £100 pound bike, where if I ballsed it, I wasn't going to be bothered. I might have a different view doing this on the Falco!