removing broken header exhaust studs

[fatfreddy000]

so,been trying to install the new split flange i made up today on the front cylinder header.
managed to get the old rotten flange off with a bit of elbow grease, a hammer, and a dremel.
the studs snapped of pretty short when i attempted to remove the retaining nuts (as expected). i tried using a Beta 7mm roller stud extractor but the tool broke at the first hint of it grabbing the stud- i am thinking this is because there was insufficient length of stud inside the roller mech- the actual alloy casting that houses the rollers inside has sheared away, looks to be a very cheap brittle alloy.
anyway, so now I'm left halfway through the job with the sun setting and no time till next monday to continue..
my next idea is to try and get 7mm or 8mm nuts over the remnants of the studs and weld them on then try and extract with a socket set- unsure how seized there are gonna be in there but the heat from welding them should help free them up by expanding/contracting the steel within the aluminium thread of the cylinder block.
has anybody else had similar issues here?
any ideas of tips from the experienced kindly welcomed..
i will post photos of the upgrade ONCE it gets completed!

[AMCQ46]

some time ago someone managed to get the stud out by using a dremmel to cut the first 2mm of casting off the cylinder head boss [without cutting through the stud], and this was enough to detach the area with the corrosion that was causing the stud to seize .... then the stud then came out of the head easily.

the fact that yo have taken 2mm of the boss is not a problem as the flange is not pulled up to the cast face in normal assy, so you just have a bit more gap and a bit less tread engagement with your new stud.

[cheekykev]

I tried that idea of welding the nut on and trying to undo it, unfortunately it didn't work, I'm not sure what metal the stud is but it's is very hard so therefore very brittle and just keeps sheering off.
The first thing you may think is to question my welding skills, but I can assure after 40 years in the game my welding skills are up for it, but by all means give it a try, you've nothing to loose.
In the end I drilled down the centre of the stud and re-tapped it, just make sure you stay on centre and in line when drilling, first using a pilot drill and then increase up to the correct tapping size, I'm almost sure it was 8mm standard thread, so the tapping drill would be 6.8mm.
Note the part of the stud that goes into the head is 8mm and the part sticking out is 7mm, and I'm pretty sure they're not that expensive from a main dealer.

[MacV2]

some time ago someone managed to get the stud out by using a dremmel to cut the first 2mm of casting off the cylinder head boss [without cutting through the stud], and this was enough to detach the area with the corrosion that was causing the stud to seize .... then the stud then came out of the head easily.

the fact that yo have taken 2mm of the boss is not a problem as the flange is not pulled up to the cast face in normal assy, so you just have a bit more gap and a bit less tread engagement with your new stud.

A picture saves typing a 1000 words...

[AMCQ46]

thanks Mac, can I delete my post now

[MacV2]

thanks Mac, can I delete my post now

No . Think of it as teamwork Al, you write it, I show it...

The 1000 words comment wasn't meant as a dig...I didn't even count them...

[AMCQ46]

If you were a true local from Grain, you would have been able to count all the words on the spare fingers and thumbs on your 3rd arm

[fatfreddy000]

great,
thanks for the replies.
i guess i will try welding it first even if its likely to snap.
I'm surprised the beta roller extractor broke and I'm waiting to see if the seller will send me another- id so i have another chance if i cut down the aluminium around the stud hole a bit..
last resort will be grinding flat and recapping.
thanks again,
mat,

[KermitLeFrog]

I filed two flats on what remained of the stud. Enough to get a grip with some mole grips.

Put a lot of heat into the head and stud with a propane torch.
Clamp mole grips on stud
wiggle wiggle
Removed molegrips

Put a lot of heat into the head and stud with a propane torch.
Clamp mole grips on stud
wiggle wiggle
Removed molegrips

repeat...

Took a while but eventually the wiggle wiggle became is little bit of a turn and eventually they screwed out.

[Varastorm]

I took this job on a few weeks ago, nightmare tbh.

http://www.vtr1000.org/phpBB3/viewtopic ... 50#p454610

[fatfreddy000]

the seller is sending me another beta extractor as he thinks the last one was faulty by the way the roller cage cracked.
i doubt the new one will be strong enough to do the job anyway so i will be attempting to ark weld a nut onto each stud and use loads of heat with a propane torch and then wiggle back and forth with WD40 and pray!
by the state of the flange, and infact the bike in general when i purchased it, i wouldn't be surprised it the header's not been removed since it was factory fitted (before 2001!)- its in a right dirty corroded old state so fingers crossed it will come out otherwise i will be trying to drill and extract or drill and retapp..

[Wicky]

then wiggle back and forth with WD40 and pray!

Try using Plus Gas

"Plus gas formula 'A' dismantling lubricant for de-seizing all corroded metal parts, penetrates deep down to break the grip of rust, scale, carbon, paint or gum."

[VTRDark]

More commonly known as canned Mac

[fatfreddy000]

I tried that idea of welding the nut on and trying to undo it, unfortunately it didn't work, I'm not sure what metal the stud is but it's is very hard so therefore very brittle and just keeps sheering off.
The first thing you may think is to question my welding skills, but I can assure after 40 years in the game my welding skills are up for it, but by all means give it a try, you've nothing to loose.
In the end I drilled down the centre of the stud and re-tapped it, just make sure you stay on centre and in line when drilling, first using a pilot drill and then increase up to the correct tapping size, I'm almost sure it was 8mm standard thread, so the tapping drill would be 6.8mm.
Note the part of the stud that goes into the head is 8mm and the part sticking out is 7mm, and I'm pretty sure they're not that expensive from a main dealer.

i may have to do this yet.
if i do i will just use straight 8mm stainless threaded bar all the way.
do you know how deep the stud get into the head?
i dont wanna drill+tap to deep!

[cheekykev]

i may have to do this yet.
if i do i will just use straight 8mm stainless threaded bar all the way.
do you know how deep the stud get into the head?
i dont wanna drill+tap to deep!

If you go in up to 20-25mm you'll be fine, I went in about 25mm, the stud is very hard so you will need cobalt drills.