Exhaust header stud broke

[jcgss77]

Ok, so you may have seen my post in the for sale section regarding my exhaust. I was removing it a couple weeks ago, and then my wife and kids and I all got sick (yuk) and now I am back into repair mode.

Anyways, as I was taking off the nuts on the header, both of the inner studs broke off. I am freaking out pretty bad, and I am hoping that someone can help me out with a fix to this. The rust is major on the bolt stud and nut, but the header is only slightly rusted. This seems to me to be an issue the previous owner did not address when they changed the exhaust. All help is appreciated.

[Motofool]

Steel that bolts into aluminum always cause a corrosion that tends to weld both metals.
The above could be the reason for the need to apply extra torque on those nuts that sheared the bolts.

The studs need to be removed from the cylinder, but first, you need to soak those for some good time with some penetrating oil; my favorite is a mix of acetone and marvel oil.

Finally, if you have nothing to grab them with, you will need a stud's extractor or taking the bike to a machine shop for them to use theirs.

[jcgss77]

Originally Posted by Motofool

Steel that bolts into aluminum always cause a corrosion that tends to weld both metals.
The above could be the reason for the need to apply extra torque on those nuts that sheared the bolts.

The studs need to be removed from the cylinder, but first, you need to soak those for some good time with some penetrating oil; my favorite is a mix of acetone and marvel oil.

Finally, if you have nothing to grab them with, you will need a stud's extractor or taking the bike to a machine shop for them to use theirs.

That does explain it. I will begin the bathing process immediately. Which leads me to some more questions:

Do you have a preferred mix of the acetone/marvel oil, 50/50?

And will vicegrips work to take those out, after a good soak?

[Motofool]

Originally Posted by jcgss77

That does explain it. I will begin the bathing process immediately. Which leads me to some more questions:

Do you have a preferred mix of the acetone/marvel oil, 50/50, and what is marvel oil?

And will vicegrips work to take those out, after a good soak?

Yes, 50/50 is what I have used.
You can replace the Marvel Oil with ATF or Air Tool Oil.

http://www.marvelmysteryoil.com/

If it is really bad, vice-grips may not be able to hold the stud strongly enough, but I would try that first.

Avoid drilling the things out, as precise centering is difficult and it is easy to destroy the aluminum threads.

http://advrider.com/forums/showthrea...ighlight=studs

[baz666]

I've been there and I sympathize. It's true, drilling can make things even worse. Hopefully soaking and vice grip method will work.
If not, there's Spark Erosion. An electrical current is attached to the offending stud and the metal is eroded and broken up.
A high school shop teacher did it for me on my old Suzuki and it worked great. If all else fails, call around to some electrical shops or machine shops and ask if they do it. It's not a difficult process and they shouldn't charge much.
Good luck.

[dcj13]

Originally Posted by Motofool

Steel that bolts into aluminum always cause a corrosion that tends to weld both metals.
The above could be the reason for the need to apply extra torque on those nuts that sheared the bolts.

The studs need to be removed from the cylinder, but first, you need to soak those for some good time with some penetrating oil; my favorite is a mix of acetone and marvel oil.

Finally, if you have nothing to grab them with, you will need a stud's extractor or taking the bike to a machine shop for them to use theirs.

All true!

Automatic transmission fluid and acetone (50/50 mix) is my favorite.

[accumack]

i've removed them by welding a nut to the broken stud. The heat from welding seems to break them loose.

[Ginganinja]

^^^this. if you have a butane torch try heating up the stud for a couple minutes. It's the preferred solution for removing o2 sensors that are stuck without damaging them. I don't see why it wouldn't work here as well.

"liquid wrench" is another good penatrating oil, always worked for me.

[fast1075]

If it breaks flush, pull the head and take it to a machine shop. (Call around to find one that does this) It is correctly called E.D.M. (Electrical Discharge Machining). Correctly done, they can remove the broken stud completely without damaging the threaded hole.

I said pull the head because most shops will not attempt it with the head in place due to access difficulty.

Hopefully you can get it out. The welded nut/solvent soak is a very good and usually productive idea.

[flitecontrol]

Originally Posted by dcj13

Automatic transmission fluid and acetone (50/50 mix) is my favorite.

And in a test with PB Blaster, Liquid Wrench, and some others I can't recall at the moment, was found to be more effective.

[Racer x]

To fix this really takes skill time and a little luck.
PB blaster is extremely effective. Heating the broken stump just a little with a propain torch then spray PB Blaster on it. Let it sit for a couple days or over night. Then go after it with a very small drill. Drill a tiny little hole straight through the broken stud. Then heat it up just a little and soak it with PB Blaster again let it soak over night.
Next step is a reverse drill. This will follow the little hole and if you are lucky it will pull the broken stud. This all seems like a boat load of trouble. But that is what it takes.
If you drill through the stud with a backward drillbit then it can be completed with my favorite thread repair kit. WWW.Timesert.com
Or pull the head and give it to a machine shop. Like I said this is either a skill fix or luck fix. But it can all go wrong instantly. Like if the drill brakes off in the stud. Remember the stud is harder on the outside. So if you drill crooked you are headed for disaster.

[thumper64]

I had one break and I put two nuts on the stud so i could use a wrench. I heated the aluminum with a torch a little bit. Not enough to get it too hot, but I let it heat for a minute or two to expand it.

[Ginganinja]

Any updates? Did you get the stud out of the head?

[jcgss77]

Originally Posted by Ginganinja

Any updates? Did you get the stud out of the head?

Still soaking it. I am ordering a stud extractor, so it will give it a good amount of time to break loose so I can hit it with that.

So, thinking forward, I really don't think I will be installing new studs there, is there any problem with using just bolts to mount the exhaust headers? I will be going to stock headers, and was considering using stainless steel bolts. Anyone else replace the studs with bolts?

[Motofool]

Originally Posted by jcgss77

........is there any problem with using just bolts to mount the exhaust headers?.......

Wear of the aluminum threads and length of bolt needing to be less than the threaded depths (but no much shorter or aluminum threads will be overloaded).

[justanotherone1]

Sorry for revving thread, but does anyone know the size and diameter for replacement Exhaust Studs? I can't seem to find them at all...

[ducatiman]

6mm x 27mm kaw part# 92004-066

[justanotherone1]

Originally Posted by ducatiman

6mm x 27mm kaw part# 92004-066

Thank you so much! I will my first born after you mister Ducatisto.