Ugh! Why did my exhaust stud break off? --UPDATED--SUCCESS!!

Last Sunday, I was out on a ride. I had been out for a couple of hours and was now not far from home when I noticed a bit of rattling/vibrating that seemed to be coming from the front or possibly top of the engine. I couldn’t find anything noticeably wrong when I pulled over, so I continued home, taking it a bit easier than normal. The bike was parked all week until yesterday when I decided to look it over/take it for a spin to see if I could determine the source of the noise. As I was riding/listening to how it reacted to various rpm's, the rattle became nosier suddenly and I could hear clearly that it now had some exhaust noise at the headers, too. I found that one of my exhaust collars was loose and just hanging there on the header. One of its studs was broken off on the cylinder head, about 2 or 3 threads in, and the other nut was gone, with the stud still sticking out. I borrowed a nut from one of the other exhausts (leaving me with two of my exhausts each only having one nut) and gently drove to the hardware store. I got a couple of stainless metric nuts and put them on the 'donor' exhaust stud with a screw-driver-handled nut driver, because I was fearful of applying too much force.
So now I think that when the vibration first started was because I lost a nut and when it worsened and got loud was because the opposite stud broke off due to imbalanced forces of being nutted from only one side. Dang, I wish I had spotted that missing exhaust nut when it first happened!

So should I be getting some Kroil and easy-out extractors? Anybody with experience want to offer tips or advice on what to do or what NOT to do in trying to remove that stud? (Hot/cold, on the bike or off the bike, etc)

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix

Ok, so I found and read a few threads about broken studs. Yikes!
Fitz has recommended a chemical product which I think I might want to try. Can this be done on the bike or do I still have to pull the head? Has anyone here tried it yet?

And can the bike be ridden a bit like this while you are wating for the stuff & time to repair it?

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

If you can take the time start out with a small drill bit and drill the center of the stud out. DO NOT DRILL THE ALUMINUM!!! If you have easy outs you can try that route but let the stud soak overnight with some sort of chemical product to loosen the screw (PB blaster or Kroil). If you are really lucky have someone weld the stud to something and then grab it with some vise grips it might break free
As for why the stud broke, it could be old age. Do you still have the stock exhaust on? If you went aftermarket, is the exhaust flange on the header pipe bent? If that's the case the flange will have to be straightened before you put it back on again.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

If there is any of the original stud sticking out. Chacal has a stud extractor that can be used to remove it.

Also give all the exhaust studs a good diet of Kroil. You will want to replace them all as you are just starting to notice what age, and corrosion will do to the soft metal that these studs were made of.

Let the kroil soak in good, and apply heat carefully at the base of the stud.
The still intact ones should turn out using a double nut approach.

Ghost

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix

Hi. Thanks for the tips so far.

The exhaust system is stock, no bent headers or flanges.
The broken stud is not sticking out, it is 2-3 threads inside. Can kroil be dabbed on the end and still start to penetrate or will it just be dripping away and falling on the ground if I don't pull the cylinder and do this on a bench? How deep in are the stud holes and are they open inside or do they have a 'bottom' (so I don't drill too far)?

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

OK, for starters, the studs aren't in there very tight.

Some of them are in "blind" holes, and some go all the way through into the spark plug gallery in the head. I'm not as infinitely familiar with the 650s as I am with the 550s so I can't tell you which is which.

If you "fill up" the hole with Kroil, it will begin to work its way into the threads AND drip out.

As for the Tap-X broken tool dissolver, I don't know if anyone's tried it yet. You should be able to use it on the bike, with the pipe removed for clearance. I believe the kit comes with clay to make "dams" with. If this happened to me, I would try it before I attempted any sort of drilling operation.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

Oh, and I missed one of your questions:

No, I wouldn't ride the bike that way; there's a good chance of breaking the other stud, or even damaging an exhaust valve.

It broke because one nut fell off, and it was hanging from the other one. Don't want 'em both broken.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

Should I be concerned about this going into the engine if the hole might be open? Do you know if the studs are the kind of steel that the tap-x will work on? Tap x is "specifically formulated to dissolve high carbon tool steels typically used for taps, cutting tools, and even fasteners." Does the cylinder head alloy contain magnesium? If anyone knows, that would be helpful! I've left a message to tech support at DGR Industrial.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

Im going to go against fitz on this one. That stuff just sounds messy, time consuming and potentially dangerous. Drill and easy out is the way to go. Any decent local hardware store should have an easy out set.

Center punch to get a good dimple to start drilling a very small pilot hole appropriate for the easy out that you are going to use. If you want you could even try to drill your pilot hole with reverse pitch drill bits. Sometimes they alone will catch enough to turn a broken stud out. Use caution with easy outs! they are very hard but also very brittle. I have some small sockets that I use for easy outs and taps that allow me to put them on the end of a driver handle reducing the chance for me to apply too much torque. Basically if it doesnt turn out as easy as a phillips head screw, dont force it more and go to plan B.

As mentioned the exhaust studs generally arent in there very tightly. If the reverse pitch drilling and easy out isnt enough (remember, go easy on the easy outs, if you break it off in there you compund your problem) then you are going to have to drill out whats left of the stud and retap the hole. If you got your first hole centered that will really help here, but basically just go up on drill bit size step by step to get to the size recommended for the tap you need. I want to say those studs are 6mmx1.0pitch, but dont quote me.

Broken fasteners are a common occurance on our older bikes. Get used to it happening the first time you take something apart that been fastened for almost 30 years. A good set of reverse drill bits and a complete selection of taps are good tools to have in any mechanics tool box.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

You're not "going against" me; I've never tried it before either. But it seems like it would be ideal in this situation.

What I have seen is case after case of somebody buggering things up MUCH WORSE than they already are by trying to drill one out.

There aren't any "open backed" holes that actually go into the motor anywhere, scratch that concern.

Here's an idea: If you'd like to test the Tap-X stuff before using it on your bike, I have a spare, "semi-scrap" cylinder head. We could test it on that first to see what happens if you like. While I'm not really up for ruining it, we could create a simulated broken stud (with a screwdriver slot pre-cut in it) and see what happens. I only paid $10 (yes, $10, it cost more to ship) for the head so if it does go horribly pear-shaped it wouldn't be the end of the world.

PM me if interested, we can work out the details. I have no problem loaning out the head in this situation, especially since you're so close it won't require shipping it.

Or, try drilling it out, and let the Tap-X stuff be your "Plan B."

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

tap-x or tap-out (brand names very, I think even ZEP makes one) kits DO come with clay for building dams for just such an occasion as holes that are not vertical.
They dissolve anything ferrous. So when you try the EZ-out extractor and break THAT then the tap-out will eat it too. As the name implies they are for removing broken taps. The magic potion doesn't care how hard the steal is so long as it's got iron it will eat it (anybody play D&D? rust monster?) and not touch metals like aluminum, titanium, magnesium.

Iron, stainless, A2 tool steel, drill bits? eats 'em all.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

That sounded like an endorsement for trying it, and I was just "going against" that endorsement.




I agree, ez outs are a bit of a gamble in the hands of those who arent experienced with them. I personally rarely bother and go startight for drill and tap.

After the issue noted with some Suzuki carbs in another thread, I would be even less inclined to pour nitric acid on ANY part of my bike.

Also from what I read its slow, and helps to drill a hole into the stud anyway to expose more surface area to the acid. Its recommended you run a tap into the threads afterwards so you need that anyway. Plus its not cheap. Add $50 to a job that requires a drill and tap anyway? It all adds up to a waste of time if you ask me. I had one broken exhaust stud and one broken intake manifold bolt to remove on my engine. Neither were particularly difficult to drill and tap. Why make the job more complicated than it needs to be?


I suppose if I had something to experiment on I would try the disolving method just for shits and giggles and have some around for a plan C...maybe, but most of what I work on is steel on steel (not so much alloy in older cars/trucks). I can drill and tap a hole in 15 minutes on a bad day though.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

The experimental nature of the possible solution was why I offered up my spare cylinder head as a guinea pig.

I KNOW it's made of aluminum, and not 'pot' metal. (It's from a Yamaha.)

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

lol, you SURE about that!? I for one am trying to stay away from making such definative remarks these days


It think experimenting is great. I love to play around with stuff like this, but generally dont have the time OR the money.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix

Thanks guys for the replies. I think I'll try reverse drilling after a few days of hitting it with kroil or pb blaster. Then if it doesn't come out with the reverse drilling, I'll try an extractor. Then if it is required, I'll try the tap-x.
I know I can get pb blaster and seafoam deep creep locally, anywhere with kroil?
Fitz, thanks for the generous offer, I'll keep it in mind and PM you if I get the tap-x.
I will post here when/if I have some results to share!

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

My first attempt would be to try a left handed bit. I've had very little luck with screw extractors, aside from cases where a bolt's head was sheared off and there was no corrosion to start with.

I take that back. My first attempt would be to weld a nut to the stud with my mig welder. This can be accomplished even if the stud is broken off several threads down in a hole. Just build up a stalagmite of weld to the stud, then weld it to the nut. The heat of welding tends to loosen it, too. If it doesn't immediately free up, then i use a propane torch to get the nut red, or even yellow hot. The aluminum readily absorbs the heat, so you gotta get it hot. No munged up threads have ever resulted.

I realize not everyone has a welder.

Since ez-outs do a fantastic job of breaking off and making this even harder, if their use doesn't give immediate results, I drill the whole stud out, get an appropriate helicoil set, drill what's left of the bolt and the threads out with the provided drill bit, tap the hole with the special helicoil tap, and install helicoil with the original thread pitch. I hate the process of just tapping to the next size up, and the resulting drilling oversize of whatever mounts to it. Helicoil is expensive, but professional, and permanent if done correctly. Threadserts are also acceptable, if there's enough surrounding material to support the much larger hole that has to be drilled to contain it.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix it?

one thing about EZ out extractors. NEVER follow the directions on the package. That is, banging the thing in there with a hammer. All that does is expand the stuck stud or bolt and swage it tight into the hole.

Left handed drill and if you can get your hands on it, a left handed tap. If not then just apply firm pressure to the extractor and drive it CC with the drill.

I'm prejudiced against EZ outs, frame sliders and a few other things. The only ones I ever get to see are the ones that failed.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix

Well, I ordered parts (studs/flange nuts/gaskets) and began a regimen of spraying with 'Deep Creep' (by Seafoam) penetrating oil. I'll apply the oil every day until the weekend and then see if I can reverse drill + torch heat to get the busted stud out.
Sidenote, I googled for 'pb blaster vs kroil' and 'best penetrating oil' and found discussions on many forums and blogs. Between pb, kroil, deep creep, liquid wrench, the candlewax/beeswax methods, ATF /acetone mix, there is no definate favorite out there on the web. Each of the above has people in it's camp as 'the best'. Even though I'm probably slightly biased toward Kroil (due to the fact that it is best in Fitz's opinion), I wanted something I could get today. I stopped at the local Napa/Auto Repair shop and asked the auto mechanic what was the best among what they sold. They have PB B'laster, Liquid Wrench, and Deep Creep. Without hesitation he said Deep Creep was the best, so that's what I got. It was the most expensive, so either it really is better or I really am gullible!

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix

Sorry I didn't get back sooner.

Kroil isn't a retail product; it says so right on the can. It used to be only sold through industrial supply houses, until they decided to start selling directly to the "public" (to people who knew what they were looking for.)

I didn't "discover" it. I was struggling with rusted-in fork caps on my '81, one of the last things I needed to fix (fork seals.) I tapped them down enough to clear the rings, and they wouldn't come back up. So for nearly nine months, I shpritzed every product you can buy down in there and kept riding the bike, hoping they would break loose. Didn't happen.

Then a forum member, Alkasmeltzer IIRC, recommended Kroil as the only penetrant he'd ever seen actually WORK.

One cap popped loose while I was eating dinner (less than an hour) and the other about 10 minutes after applying Kroil.

Been a disciple ever since. I bought two cans three years+ ago, and just cracked into the second can earlier this summer. http://www.kanolabs.com/google/

I used to swear by PB Blaster, and yes I tried Deep Creep. And Liquid Wrench. And JB80. And CRC "Freeze-Off." NOTHING WORKED until I tried Kroil.

I'm still using the others up cleaning tools with them, etc.

In your case, the Deep Creep will likely suffice. But get some Kroil, you'll need it.

Then, before you try to drill AT ALL, get some left-handed drill bits. I'll bet as soon as a "reverse" drill bites into what's left of the stud, it's gonna wind right out. It's NOT "rusted" in place, it's steel and the head is aluminum. It's just corroded and probably not actually seized at all. Worked great on my master cylinder screws, I didn't even need the actual extractor.

 

Re: Ugh! Why did my exhaust stud break off? And how do I fix

Fitz, thanks for the specifics on the penetrants. I might still order some kroil, I just wanted to have something now to get started with. Kanolab's order page doesn't detail how much they charge for shipping so you have to fill out all your name/address/credit card info then submit your order without knowing total cost.

But, I just searched (love google!) and found this:

Google Deal Orders 866-487-7245
Google Deal - (2) Aerokroil King Size 13 oz. aerosol cans - $12.00 plus $5.95 shipping and handling. Limit (1) per customer

http://www.kanolabs.com/google/

I'm on this!


And yes, looking for left handed drills tomorrow when I'm on the road (in my work van) :cry: