Snapped exhaust stud

[MikeO]

I've sprayed Plus Gas onto the exhaust nuts on the headers of my 1150 Adv every day for the last week. So today tried undoing the most accessible one.

Fairly predictably...

So I've not attempted any of the others, just given them a good dose of Plus Gas while I think about what to do next.

I last had the nuts off when I refitted my ceramic coated headers back in 2005. I replaced the nuts then, with BMW's modified dome design. The dome had rusted right through...

I don't know whether the hole was there before I broke the stud, or if it broke through as a result of my putting the socket onto it.

I am now tempted to ride the bike to a local engineering shop to get this stud removed and replaced, and the other nuts removed. Whatever happens I think I'll replace all the studs - this one looks seriously corroded.

Any other ideas?

Mike

 

[AberdeenAngus]

I would be tempted to agree with you. Replace them all. They'll all be as bad as that one.
If it's not something you're up for yourself then down to the workshop with it while it's rideable.

 

[Posh Pete]

1. Leave it and hope it doesn;t leak?

2. Try to remove the others. If they shift, then it's only one head you have to whip off to get the broken stud removed! I doubt if the shop will manage with the head in situ.

Happened to me on my 11RS. It's a bugger of a job. I had to drop the paralever to get the exhaust off!

 

[ghiribizzo]

As mentioned - I suspect that the engineering shop will chase you away with the bike. They'll want the heads off. They'll not dismantle exhausts and headers.
You don't need to dismantle the heads off to get them out. Drill and dremel them out. Carefully...
I screwed up one - so that got Helicoiled. New stainless studs in with a little PTFE so they'll come out again if needed.

 

[High-Tower]

I reckon you'll have to have the heads off. Then it should be a fairly simple job to have the studs spark eroded by an engineering shop. I don't imagine they'll touch it as a complete bike.

 

[ghiribizzo]

High-Tower - I wish I'd had more guys thinking like you when in the workshop.
"Here's my bike - please take the exhaust off and the cylinder heads. Then take them to ABC Eng. Co. for Spark Erosion and then fit new studs and reassemble..."

Sure. That's the obvious fix for Mike O.

 

[seags]

I reckon you'll have to have the heads off. Then it should be a fairly simple job to have the studs spark eroded by an engineering shop. I don't imagine they'll touch it as a complete bike.

This happened to me recently, tried every thing including freezing the stud and heating the head - no joy. Heads off and helicoiled all 4. Just putting her back together now and looking forward to getting her back on the road.

Good luck with it.

 

[MikeP]

I had one snap off. In the end I just filed the end flat, centre-punched it and then drilled it out in situ, picked the thread clean, ran a tap down it and screwed in a replacement stud.

A decent set of drill bits helped and a slow speed drill but first it was plucking-up the courage to give it a go.

 

[ghiribizzo]

Hurrah for common sense. Some things you DO need the heads off for. Broken exhaust studs is not on that list...

 

[northengit]

Hurrah for common sense. Some things you DO need the heads off for. Broken exhaust studs is not on that list...

Now now calm down....

 

[AndrewD]

Try the others with a hot engine!

 

[Smug]

I can recommend this stuff for freeing off seized exhaust manifold nuts. Expensive but it works.
http://www.motorcyclesparesuk.com/product-p/105079.htm

If you do decide to try and drill out the broken stud, a centre drill such as this is the best way to start drill into the centre popped stud

 

[ChrisH Kerry]

I can recommend this stuff for freeing off seized exhaust manifold nuts. Expensive but it works.
http://www.motorcyclesparesuk.com/product-p/105079.htm

If you do decide to try and drill out the broken stud, a centre drill such as this is the best way to start drill into the centre popped stud

I have had some success by tacking a welding rod onto reluctant studs, the heat and current seem to loosen the hold (always disconnect battery beforehand when using electric welders)

Good tip using the centre drill - wouldn't have thought of that but much easier than standard drill bit to get started

 

[MattW]

I reckon you'll have to have the heads off. Then it should be a fairly simple job to have the studs spark eroded by an engineering shop. I don't imagine they'll touch it as a complete bike.

Why would they need to spark erode it?

Spark erosion is used when you've been stupid and snapped off a hardened steel stud extractor in the stud.

An engineering shop will just drill the old stud out and helicoil it - bread and butter work for most automotive engineering places.

Both the inboard studs on my 1100 snapped off when I removed my exhaust (the other four just wound themselves out of the head with the nut still firmly rusted in place). As I was changing a head gasket and having the head skimmed (the reason for taking the exhaust off in the first place), I just took the head to an engineering shop and £20 later it was helicoiled. The other snapped stud, I just left in place (so just two studs holding the exhaust on that side - it's been fine and I've heard Steptoe say there are loads of 11xx's driving around with one stud on each side).

The four studs that removed themselves got replaced with stainless (using zinc chromate anti seize) and all refitted studs had brass nuts fitted rather than the stupid domed things - no more rusted nuts...

In your case, if you're reasonably confident with a drill / tools, I'd do what MikeP says and drill it out yourself and possibly the others that snap when you try to remove the exhaust - I'd have done this if I wasn't already taking the head off and having it skimmed.

Be aware that if you remove the head you'll need a new head gasket - they aren't the cheapest and can't be reused.

 

[High-Tower]

Fair one, I'm happy to stand corrected.

 

[Fanum]

A slightly different variation of the problem here, but I appear to have one stud spinning in the head.

The thread on the stud showing outside is fine, but the bolt won't tighten up on it, just feels like it's spinning the stud in the head at about 6-8 nm (hand tight with two pinkies off sort of tightness)

The other ones tweaks up quite nicely

I've just put a lock nut on the stud and tried screwing it back in with the 10mm bolt tightened down on it and it did appear to move back in, but it's obviously fekked.

Thoughts please?

I no longer have a tap and die set, but if I got one, tapped it out and fitted a bigger stud, is that likely to work?

Is that do-able in-situ?
I really really want to avoid having to take the head off if at all possible

 

[MikeO]

A slightly different variation of the problem here, but I appear to have one stud spinning in the head.

The thread on the stud showing ourside is fine, but the bolt won't tighten up on it, just feels like it's spinning the stud in the head at about 6-8 nm (hand tight with two pinkies off sort of tightness)

The other ones tweaks up quite nicely

I've just put a lock nut on the stud and tried screwing it back in with the 10mm bolt tightened down on it and it did appear to move back in, but it's obviously fekked.

Thoughts please?

Can you use the same locknut method to try to remove it?

Mike

 

[Fanum]

Can you use the same locknut method to try to remove it?

Mike

I'll give it a go when it's cooled down

I'm only guessing, but I suspect yes, as it seems to go IN ok.

I can't live with the twittering noise of the blow, but at least it's rideable now with the cleaned up injectors back

 

[MikeO]

I guess you'll be able to work out where the snag is when you retrieve the stud. I hope it's the stud, not the head - although I see no reason why you couldn't helicoil there if required...

By the way, I ended up riding my Adv over to a local engineering firm. They snapped all the studs trying to get them out - so I certainly would have. They ended up welding bar to the stubs and turning them out, with the aid of some heat.

Interestingly, the threads in the heads were fine and were not corroded. The rust on the outside had thinned the studs down and weakened them. They have been replaced with (well copperslipped) stainless studs and (for now) mild steel nuts. The nuts will be replaced, probably with brass, when I replace the headers in a few weeks time.

Mike

 

[steve'o]

Whip the exhaust off out the way and then do a helicoil repair. No need to remove head and will be stronger than new.