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Discussion Starter #1
I just found the top exhaust stud on the rear head broken. It is broken off flush with the head. I have a small starter hole drilled in it pretty close to center of the stud. I am wondering what is the best device and size to attempt to extract it would be.

I have a set of "easy outs". The hole I have drilled now is pretty small, for a small easy out, but I am afraid it will break if I have to put any torque on it. The next size up is pretty big in comparison and I don't want to run myself out of options. I am trying to do this on the bike since I just this winter redid the top end. I would hate to have to tear it down again.

Any tiip, tricks, tools and suggestions will be greatly appreciated.
 

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Broken bolts are a pain the a$$. I have had some luck lately using left hand twist drill bits. When you drill into the broken bolt and right before you drill through, sometimes the bit will catch and twist the broken part out. Other than that, be careful and try not to break the easeout.
 

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Soak that puppy in WD-40. Left handed drill bits and a very slow speed are a good option (as Dav pointed out). Good luck.
 

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+1 on the WD40.

$0.02 = Maximize that hole you have drilled - the thinner the walls of the old stud, the better . . . but don't be so aggresive as to affect the female threads; this larger hole allows you, also, to maximize the size of the easy out. We used to make our own with some HSS on a grinder, customized if you will to our tasks . . . the radius of a grinding wheel would put some curvature to the point - not fancy, four ground sides as identical as possible - the sharp edges would create the bite needed.

Good luck!
 

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Discussion Starter #6
No luck so far. Been soaking it with Liquid Wrench and Croil, tapping on it with a hammer and punch and heated it up some. I can get a good bite on it, but it won't turn with the amount of pressure I'm putting on it with the screw extractor. I don't want to break the extractor off in it.
 

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+1 on the bigger drill bit. The left handed feature is a benefit. Don't screw around... If you don't have the right tools... You're better off getting them than trying to make-do with what you have

My 2 cents.


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Ace Hardware sells a 3 pk asst sizes of the Lh drill bits with the sprail extractor attached .
I think there pretty cheap .
Lowes or Home depot might even have them

try some P B blaster It's great on rusted stuff but you have to use it first
 

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Yes, to enlarging the hole as much as possible without damaging the head threads. A broken extractor usually means removing the head.
Buying a few bits or extractors will be cheaper than R&R' the head.
 

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Discussion Starter #10
I've got the hole a decent size and am using the largest Irwin left hand spiral extractor that will fit the bolt. I quess I will try the Pro Grabit next, that is as soon as I can find a set.

I'm thinking I'm going to have to drill it out and retap it though. I was reading another thread on this forum about broken studs and I understand the threads are "interference fit , meant to be very tight when installed and so it won't screw out when removing the nut", according to Schmidtys.
 

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Maddog
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The trick to this operation is to get the pilot hole on DEAD CENTER of the broken
stud. If you're not centered (or pretty damn close) you're going to have problems.

You're probably going to have to take the head off at this point. :( You break an ez-out
off in there and you're really screwed!
 

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An old machinist trick would be to also add some heat and beeswax. Been a repair machinist for quite some time and it works well. Careful when tapping on it with a punch as it can damage the internal threads. Be patient and work it slowly.


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Discussion Starter #13
The trick to this operation is to get the pilot hole on DEAD CENTER of the broken
stud. If you're not centered (or pretty damn close) you're going to have problems.

You're probably going to have to take the head off at this point. :( You break an ez-out
off in there and you're really screwed!
10/4 - The small hole I started is close to center - got a jig coming to expand it. I'm just smart enough to know not to break an ezout off in the hole. Lets hope I'm smart enough to fix it.
 

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Broken screw extraction

Hey Bikedelic,
Really71 has the right idea and I am a retired Machinist also. You are going to have to put some real heat on it and not just a little. But take your time and you'll get it. A good Machinist never gives up.
 

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An S&S tech gave me this tip on broken exhaust studs a few years ago. Have done this several times and it works !
Weld a steel nut to the end of the stud, even if it's broken off flush. A wire welder works perfect. Hold the nut against the stud and weld the inside of the nut to the stud end.
Also the heat from the weld will help to loosen it up.
 

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Also when welding on a motorcycle disconnect the battery and unplug the regulator connector.
 

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an s&s tech gave me this tip on broken exhaust studs a few years ago. Have done this several times and it works !
Weld a steel nut to the end of the stud, even if it's broken off flush. A wire welder works perfect. Hold the nut against the stud and weld the inside of the nut to the stud end.
Also the heat from the weld will help to loosen it up.
THAT - is a great idea!
 

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Maddog
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That will work

An S&S tech gave me this tip on broken exhaust studs a few years ago. Have done this several times and it works !
Weld a steel nut to the end of the stud, even if it's broken off flush. A wire welder works perfect. Hold the nut against the stud and weld the inside of the nut to the stud end.
Also the heat from the weld will help to loosen it up.
Make sure you let it cool completely before attempting to take it out.
Ya might also want to heat the surrounding area of the aluminum
after the stud has cooled off...
 

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Discussion Starter #20
Thanks all, I drilled it out with a Jim's exhaust stud drill jig. I drilled a 1/4" hole in the center of the broken stud, then opened it up to 5/16"X18 tap size (17/64"). This allowed me to pick the remains out of the threads a little at a time. I drilled to tap size a little at a time, picked the remains out in chunks when the bit started to bind, then drilled a little more. Once all the remains were out, I cleaned up the threads with a tap.

One thing I learned in the process is that a left hand twist drill bit would have made it easier and probably helped pull the remains out. The hole is a little loose up front, but nice and tight deeper in. It is no longer an "interference fit, so I am using a grade 8 cap screw to bolt the flange.

It's all back together and I an riding again - so far, so good.
 
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