Help - Info required from the knowledgeable

[Hawkeye]

I took off the exhaust to do some work on the bike. 1 of the nuts holding the exhaust flanges to the block came off no bother. 2 others unscrewed the stud out of the block. Unfortunately, the last one snapped the stud which is still in the block. I have managed to get the stud out of the one that the nut came off but how can I get the last stud out.

Luckly for me, it snapped at the nut end rather than the block. There is about 12mm protruding from the block and I have spayed it with CRC for a couple of days now. I don't want to snap the last stud in the block so am very wary of just putting grips on it and trying to unscew it.
Is it safe to heat up the block around the stud prior to using the grips?

Any help would be much appreciated.

[onearmedbandit]

Spraying it with CFC? Surely you mean CRC, they band CFC's a while back . If it's snapped off it's probably pretty stuck in there, buy an 'easy-out' to remove it.

[Hawkeye]

Spraying it with CFC? Surely you mean CRC, they band CFC's a while back . If it's snapped off it's probably pretty stuck in there, buy an 'easy-out' to remove it.

Thanks for pointing that out OAB. I nearly put DW40 which is what I used in the UK.

What is an 'easy-out'? I've never heard of them!

[Kwaka14]

you're going to need to drill the centre and use an "easy out" to get it out, and it's not all that easy sometimes...

[onearmedbandit]

It's a tool which after drilling a pilot hole in the stuck bolt you screw it into the bolt, then reverse it out.

Here ya go. (pic of 'easy out' 2/3 down the page.)

[T.W.R]

Bolt the exhaust up again with the other studs, start the bike up run it till warm, spray CRC in around the broken stud then remove the exhaust again. The heat of running the engine will heat the stud from the cylinder head out and spraying CRC on it when it's hot will draw the CRC into the thread, then have a go with vice grips. Aluminium heats faster that steel so the cylinder head will expand more than the broken stud.

If that doesn't work then weld a tang onto the broken stud and use that as a lever

The stud is only heat fused into place and wont take much to get started, it's just the initial bite to get it moving that's the trouble

[Max Preload]

So the stud is broken off proud of the head, not flush with it?

Use a stud remover. It's like a deep socket, but instead of having a hex in the end it has 3 rollers that operate like a sprag (one way) clutch and grip the stub because they're each in a spiral flute and as it turns they move inwards and grip the stud. It's what's used for installing the studs in the first place.

I'll get a photo of one onto here for you tonight, when I get home. I'm sure you'll be able to borrow one locally (most decent mechanics have them) but if you get stuck let me know and I'll lend you mine & courier it down (work satchels are great, aren't they!)

In the meantime keep saturating it in WD40 (CFC 5.56 is pretty useless).

When you put it back together use some chrome antiseize (local bearing resellers stock it in small plastic tubs). It reduces galvanic corrosion between the stud and the head which is what causes it to get 'frozen' in the first place. I can go easily 3 years without removing the wheel nuts from my boat trailer using that stuff, and once I crack them loose they spin off easily by fingertips along the rest of the stud length.

[Max Preload]

Here they are.