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Project bike

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Spitfire:
I wouldn't give up just yet, you have nothing to lose giving it the hot, cold, soak, treatment, you might just get lucky.
My bike had done 19k since I bought it new but had sat for 10 years, I was originally just going to go for a quick service and start riding again, but it was too far gone.
I had toyed with the idea of doing a top end strip before the stud business as I was concerned that the rings might have gummed up, in the end I found one chipped valve and a trapped piston ring.
I took my head to a car engine shop, I wanted to strip the old paint off so they put it in a bath for me for a week, this took care of all the flaky paint, then they drilled and helicoiled the stud. When I put it back together I made sure that all the studs had heat proof anti sieze on (copper based) plus all the steel/alloy bolting had copper based grease as well, all torqued properly to boot.

Cheers

Den

K2-K6:
Hi Waggles

 I'd go at it like this:-

The main reason these break is that the nut doesn't reach the end of the thread and most likely has no grease either. Nut siezes, weak point where threads end snaps off as it's most likeley also been reduced at this point by by corrosion.

Soak in "Plus Gas" either by making a small captive bowl around it (body filler) and leave to soak overnight.

Then make a tool out of steel bar by drilling one end to fit over the stud and almost reach the head and file a hex shape on other end to take a socket / spanner. Then cut vertically into the stud end to the full depth of the bore, if you put it on the stud now you should be able to look at the stud through the slots just cut if that makes sense.

You then need to arc (plain arc / TIG are stronger than MIG) weld along the slots to attach to the stud along both slots, this distributes load along the stud and gets it through a heat cycle.

Leave to cool off then tweak it forward and back with a socket (six sided) to see if it will move, if it won't come out like this it's doubtful it would at all

 

Waggles:
Thanks for all the suggestions guys. I will give it a try as its stupid not to really just in case. Had already thought about the piston rings ( I bought a new 'old stock' CB500T once that suffered from stuck oil rings even from new which I had to replace ) but I reasoned even 'just' a top end strip on a bike this old would be a world of pain so I would give it a go without first, beginning to look like it will be needed now anyway, lets just hope no more studs go!

Will post what happens.

K2-K6:
A little bit more, I think the studs were originally put into the head with a sealant that is heat proof to prevent them backing out when normal removal / fitting of an exhaust takes place and it is this that makes them seem tight in the casting. This is why if you can get a good secure hold of them they will come out as it's like breaking a loctighted bond as opposed to rusted into the ali casting.

You have in effect got two seperate problems that you are encountering 1) the nut is siezed onto the stud from corrosion and breaks the stud. 2) only related because it is the same stud and not corrosion; is the original intntion to fit the stud securely to the head by Honda with whatever loctite type compound they used. You may even be able to get something that "unlocks" the original bond, but still have to grab the stud effectively enough to apply torque to it.

If the studs are reinstalled using copper grease, then quite often they come out of the head if you try to undo the exhaust clamp but it's no big deal.

If you wanted to avoid getting the nuts stuck in future then probably an annual remove and copper greas will do, same for the plugs as well particularly the centre two as they get the most water from the front wheel.

Waggles:
YAHOO! I GOT IT OUT! and I didn't even sacrifice a virgin ( not easy to find here in Essex anyway )

I think I was lucky but it was in there very tight. heres how it went just in case it helps someone else. I soaked overnight in penetrating fluid, a quick tentative feel with mole grips showed it to still be 'somewhat stuck' I purchased a 'Professional stud extractor set' ( their words not mine ) from Halfords, Machine Mart do the same thing. These are devices that look like large spark plug sockets which have 3 eccentric doobreys ( sorry to use a technical term ) inside which grip the stud, the more pressure you put on the tighter the stud is gripped. The 8mm one can just be fitted over the stud in question, it is a VERY tight squeeze and I had to tap it on just slightly bruising the the fin below but nothing to worry about as it won't be seen. I applied heat with a blow torch attempting as far as possible to heat the alloy rather than the stud applied a little candle wax then on with the extractor and with a bit of fiddling out it came, I couldn't believe it.

Not sure the wax made any difference but I had seen it used in a u toob vid so I figured it couldn't hurt. I found the head fin below the stud tended to push the extractor slightly off line so at first it didn't want to grip but with a bit of fiddling and pushing it against the fin eventually it did.

Anyway I am off to the pub to celebrate :)

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