XBR500 Exhaust Stud Repair

[Mutt]

Can anyone offer benefit of experience?
Following putting my build project XBR back to almost completion I was able to run it up and down our road to operating temperatures as a shakedown before MOT - all very nice too except I noted that a manifold nut had undone. Transpired the nut hadn't undone it was the stud being loose which on inspection was the "araldite" melting/burning when the engine was hot - yep, the previous owner had glued it in. It was a good job as nothing was apparent when checking it over on the bench before the re-build. There is remnants of an old stud inside but it should be repairable after careful drilling/extraction with it clearly accessed.
So, my Q with this being an engine external repair is: Is it pragmatically easier to take the engine out completely or take the head off/valves/cams/cam chain in situ and reassemble?

[iansoady]

If you can get straight unhindered access I would have though in situ would work. Exhaust studs aren't too critical in terms of alignment so even if you were a little bit off it should work.

On the other hand if araldite has worked once.......

[Rossco500]

I would agree with Ian - from memory three of the studs are relatively accessible. I think access to the inner left port one (sitting on the bike) is tricky. If removing the top end also you also run the risk of shearing more of the bolts that retain the rocker and cylinder head assemblies which could add to your pain. Some of those are quite costly as are the gaskets. I had a sheared left inner stud replaced many years back by a local motorcycle repair shop and they didn't charge much and didn't have to remove the engine - might be a better option but get a quote from them beforehand. Alternatively you could remove the engine mounting bolts and plates which might allow you to tilt the unit slightly giving better access to the broken stud. Good luck with it and remember to replace all the exhaust nuts with dome nuts. Be careful removing the others too!

Regards

Tony

[themoudie]

Aye Mutt,

Commiserations! 

Having never owned an XBR or dealt with it's studs, I make no comment about whether to do the job in situ or on the bench. 

However, if you are going to have a crack at it yourself, I would suggest that you use a good sharp set (new) of left-hand twist drills to remove the stud, rather than 'Easy-Outs' etc. The left-hand thread drills are not only removing the stud, but also trying to 'undo' the stud at the same time. Plenty of PlusGas 'A' applied before and during the operation helps.

Also have a quality plug tap of the correct size to clean up the threads. Use either OME studs or frabicate your own from stainless steel, threaded rod. Use stud lock to lock the stud in place. Then apply plenty of copper grease when assembling the exhaust collars and nuts. Domed stainless nuts are preferred, but be aware that cheaper ones may not have well formed threads during manufacture and either will not thread far enough down the stud to hold the exhaust header tight against the copper 'O'ring in the head; or are insufficiently deep enough to do the same!    Using phosphor bronze nuts or stainless steel locking nuts, again with plenty of copper grease is an alternative.

SRX's have similar problems! 

I hope this helps.

My regards, Bill

[Mutt]

Thanks Gents. Your comments/advice is greatly appreciated and affirms what I thought might be easiest to access it to get the job done. Of course it will be a good reason to not go shopping this weekend whilst taking it out nor on the weekend when it gets put back in - "No, really SWMBO it will take that long" 
It felt so good to get it all together & fired up second stab of the button, so at least I'll get that benefit again...hopefully!!

Thanks again.