how to remove broken exhaust studs?

Just an idea, don't know if it would work, but if theres a lil bit of the stud sticking out couldn't you weld a nut onto the stud, and of course soak in penetrating oil, and a lil heat and get them out? Or would that not work? Not very familiar with the aluminum heads and all but I was thinking about trying it

 

After purchasing my bike I replaced a broke exhaust collar stud and replaced carb holders without snapping a single screw.

I cannot stress enough how easy these are if some heat is applied to the bosses the screws and studs thread into.

I used an oxygen-acetelyne torch with a #3 tip dialed to the absolute smallest flame I could get. Plenty of oxygen so there is no orange flame at all.

I used the same technique to extract the remains of a starter mounting bolt that snapped off.

 

I haven't had a broken exhaust stud in years. I did have one break off in the past and ended up just using that black woodstove glue to seal it just using one header bolt to hold the header pipe on and it worked. I figured the exhaust gets about as hot as my woodstove, so it should work. The stack temp reaches anywhere from 250 to 700 degress at times and I don't think engine header pipe gets much higher than that.
I am not recommending this method however, just an option if your in a hurry to get out and ride.

 

Remove the cylinder head for servicing by an experienced machinist with the proper tools if you don't feel comfortable trying heating that stud.

Just so everybody knows, for sure ... this situation, a broken-off exhaust stud, is the Undisputed Heavyweight Champion of Misery for XJ Bike Owners.

Number One.

People will say not to worry; it's OK 'cause it's not your fault and everybody still loves you.

 

Glad you edited your post, Rick...I was just about to call you on it. :wink:

 

I agree with Rick Co, this is one of those 8 on a scale of 1-10 for hardness.

The whole welding thing is for someone better than me.

I have drilled out broken studs with lefthanded bits and had good success.

I would recomend heating the head and soaking the broken stud with Aerokroil a penatrant oil. (hard to come by) then heat the head again once the stud has cooled and been flattened and centerpunched then start drilling.
DONT FORGET to drill in reverse with a lefthanded drill bit or you'll ruin it right off.

 

you have to make sure to heat the bolt and not the aluminum head. alluminum will melt faster then the metal bolt. I've had good luck with heating the bolt and cooling it off with pb blaster penatrating oil it's worked for me.

 

I've been heating the aluminum, idea is to expand the aluminum away from the bolt/stud. You're heating both (via the bolt/stud) and then quenching the steel - shrinking it away from the aluminum. Definitely a safer way to go.

Heating aluminum is very tricky, it shows very little color change going from cold/solid to molten (and is hidden by the layer of oxidization to boot).

I've found though that with the tip/flame combination I mentioned before the aluminum doesn't get that hot. I'll admit though, my sphyncter was clenched tight the first couple times I did it.

 

As long as it works that's all that matters, just use what your use to probably the safest, I know some people drill out the bolts untill there right to the treads and then use a small chissle to chip away the thin amount left, Me personally I can't drill straight enough to do this, This would work for me if I used a jig I guess, but a guy at work does it all the time free hand, it's pretty amazing.

But to each his own I guess

 

At a local electronics shop I noticed they had a spray can of fluid (gas?) that was labeled Freezing Spray......something for electronic circuit repair. I was in a hurry so I didn't study it (will next time) but I'm thinking it must be like that stuff they spray on an injury to "freeze" it and take the pain and swelling away......

I wonder if a shot of that to the stud, combined with some heat to the surrounding head material---and of course the penetrating oil----might be a great way to go?

 

I believe the stuff you are referring to is component cooler. Used to check for electronic components that fail at higher temp (spray it on and things start working again). Not sure this would be cool enough to help much.

I do like your idea though. Imagine heating that bolt cherry red and then hitting it with liquid nitrogen. Bet it'd practically jump out.

 

If you guy's are really going to do that ... could you, like ... hook-up for, like, a live webcam or have, like somebody gettin' like some good video of it man?

Either the stud gets extracted and we'll all able to do it like in the video,

or ...

You'll have a tape to send-in for a shot at the Grand Prize on America's Funniest Home Video's.

 

Palying with quick frezzing is some what harmfull, and harmfull to your self. Being in a kitchen all day you see people do dumb things and one of thoughs things are throwing ice cold water on hot steel flat top. Crack split and a lot of steam, 2dn degree burns. So i think that if you extream hot and cold togeather you may get really bad results.

But would love to see the vid of some one trying it

 

If you apply heat to the broken-off exhaust side stud, get it cherry red and hit the head with a freezing spray ... you could cause fractures to the combustion chamber.

The steel Valve Seats will heat-up along with the aluminum.
They won't cool down nearly as fast.

If the aluminum is rapidly cooled, (spray-bottle water, cold-ragged, garden-hosed, freezing sprays, what-have-you) ... you run the risk that the narrow bridge of CAST aluminum, between the Valve Seats will hairline fracture.

That's all she wrote.

 

Yep, that whole cryogenic thing is trouble just waiting to happen!

ANYONE COMINIG ALONG LATER

Please dont do this stuff!
We're just talking and tossing stuff around and thinking.....what if?

 

I am about to change the exhaust on my XJ and already sprayed the bolts with penetrating oil and let it sit over night. My plan is to hit the bolts with a hammer first, then remove the nuts. It worked on the bike I took the exhaust off of yesterday, so I hope it works for mine.
I've heard of removing the nuts after running the bike first and getting the bolts/nuts good and hot. Makes sense to me. >PD<

 

Just had to replace 2 frozen exhaust studs.. At least I was careful enough .. this time not to snap the rascals off.
Heating them Hot (almost red) with an Oxy torch .. THEN applying Parafin (candle wax) to the stud where it screws into the head ..repeatedly. then letting it cool.
This allowed the studs to be unscrewed.. rather easily actually.
I was told about this technique.. and Damned .. to my surprise it actually works. Has done so on many engines since.. be patient though this is no time for anger or hurry.
Story is the hot metal wicks the wax in and it lubricates the threads.. where Liquid wrench had no effect whatsoever.
Try it.. it works for me

 

I Just broke off 3 (I repeat 3) intake bolts tonight on my 650 :cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry:

Don't have a gas torch and after reading this thread am feeling a little put off with the prospect of getting them out.

Will put some oil on them, let em sit give them a knock and see if I can't pop the suckers out.... Failing that... Off to the bike shop it goes :cry:

 

See, everyone is using this new-fangled freezing method to get their broken studs out.......

Ha-ha.

What I was actually thinking----theoretically only----was that if you were
able to "freeze" or just cool down ONLY the steel stud with a freezing spray, and then gently, SLIGHTLY warmed the head around it (at a pretty good distance, lets say 2-3" away fron the stud, and all around), the combination of the SLIGHTLY expanded aluminum and the as-much-as-possibly-cooled steel might create just enough additional clearance to allow the stud to be broken loose.

In case I ever attempt it, I'll make a video for you guys.

 

Steel and aluminum is almost the perfect recipe for siezing. And I think Yamaha used the mildest steel they could get their hands on.

I'm slathering eveything up with anti-sieze.

I just might loosen and retighten those exhaust studs and intake screws anually too.