• Spring 2024 meetup in Calgary - tentative date Saturday, April 20/2024. Other regions are also discussing meet ups. If you want one in your area get going on organizing it! discussion
  • We are having email/registration problems again. Diagnosis is underway. New users sorry if you are having trouble getting registered. We are exploring different options to get registered. Contact the forum via another member or on facebook if you're stuck. Update -> we think it is fixed. Let us know if not.
  • Spring meet up in Ontario, April 6/2024. NEW LOCATION See Post #31 Discussion NEW LOCATION

How to remove a broken bolt extractor

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
The engine in my grandson's dirt bike locked up. It was a cam bearing that blew. My son brought me the head to remove a broken cam retainer bolt. I was able to remove the cam shaft, but the broken stud was not budging. So I drilled it out a bit and used a bolt extractor. The extractor broke off inside the drilled hole. Clearly, the extractor is hardened. A carbide cutter won't touch it. My plan is to use a burr and patience. Might have to use a diamond burr. I don't have access to EDM.

Assuming I can get the extractor out, I will just drill out the whole stud and chase the threads.

In case it matters, I have access to the far side of the stud through an oil galley in the cam shaft. I have thought about drilling the bolt stud from the galley side, and then punching out the broken extractor. There is nothing critical inside the galley. But it could damage the threads if the extractor doesn't go first.

Any thoughts or ideas?

20230424_094559.jpg

20230424_094607.jpg

20230424_094550.jpg
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
By the way that bolt may be left hand thread. What kind of bike is it?

That would certainly explain a lot! I had thought maybe red locktite. But a left hand thread would explain a lot! Shame on me for not thinking of that...... Now how to find out....

And I still have to remove the broken extractor.
 

YotaBota

Mike
Premium Member
Is the extractor the straight tapered type or the spiral fluted type?

Either way I would think you could drill from the other end and tap out the extractor, from there try another extractor going LH or mill out the bolt. If there is an EM close to the minor dia of the bolt you should be able to mill it out close enough to the thread to be able to pick out what's left of the bolt,,,,, in theory.

Fingers crossed you (he) doesn't need to buy a new camshaft.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
Is the extractor the straight tapered type or the spiral fluted type?

Spiral Fluted.

Either way I would think you could drill from the other end and tap out the extractor, from there try another extractor going LH or mill out the bolt. If there is an EM close to the minor dia of the bolt you should be able to mill it out close enough to the thread to be able to pick out what's left of the bolt,,,,, in theory.

Sounds like a plan - if I can get it out. We will see. Main problem is that I don't know the exact bolt size yet let alone Lh or Rh thread....

Fingers crossed you (he) doesn't need to buy a new camshaft.

Extra fingers crossed cuz it's really my grandson we are talking about. Not sure if my son will buy him a new camshaft. So it might end up being me. The cynic in me thinks that's really why the head is here....... Lol!
 

Darren

Ultra Member
Premium Member
I did a similar extraction for a non mechanic friend of mine. He torqued the bolt to 125 ft/lbs plus 90*. It was supposed to be 125 in/lbs plus 90*. Anyways, built it out with weld till just over flush, welded a washer to the newly built up stub, then welded a nut to the washer. Came out easy. Since the cam is cast iron, not much worry about the weld biting in to the cam.
 
Last edited:

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
I did a similar extraction for a non mechanic friend of mine. He torqued the bolt to 125 ft/lbs plus 90*. It was supposed to be 125 in/lbs. Anyways, built it out with weld till just over flush, welded a washer to the newly built up stub, then welded a nut to the washer. Came out easy. Since the cam is cast iron, not much worry about the weld biting in to the cam.


Too funny - over torquing is always such a huge temptation.


Ah yes..... Welding.......

If only I could weld that well...... Insert. Big sigh here.

Sounds like a good way to get my son to take ownership of the problem though......

I'll see how I make out with other methods first.
 
Spiral Fluted.



Sounds like a plan - if I can get it out. We will see. Main problem is that I don't know the exact bolt size yet let alone Lh or Rh thread....



Extra fingers crossed cuz it's really my grandson we are talking about. Not sure if my son will buy him a new camshaft. So it might end up being me. The cynic in me thinks that's really why the head is here....... Lol!
......yer learnin' Grampa, yer learnin'......:p
 

John Conroy

member
Premium Member
I have access to lots of motorcycle service information. If you tell me what kind of bike it is I can fid out if it's left hand thread
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
I have access to lots of motorcycle service information. If you tell me what kind of bike it is I can fid out if it's left hand thread
Apparently it's a 2016 kawasaki klx140L. I'd like to know the bolt size anyway, cuz there is zero chance the thread won't need chasing. So I'll need a tap.

FWIW, I am making very slow progress with a diamond burr. I have the top of the extractor loose. It will come out shortly. When it comes out, I'll try and drill a bit further down to see if it's all out.
 

Tom O

Ultra Member
I’ve heard of alum dissolving taps stuck in aluminum does anyone know what it does to cast iron? I’m curious now.
 

Tom Kitta

Ultra Member
Well, either EDM - which most people have no access to at home & would need to pay $$$ to use or use a trashed carbide EM to cut it out. Use EM a bit smaller then the part you are dealing with.

Most likely threads are junk anyways, no matter what you use. If possible re-thread bigger. I would start thinking of a need to either buy or make a new part.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
Well, either EDM - which most people have no access to at home & would need to pay $$$ to use

Ya, EDM isn't happening.

or use a trashed carbide EM to cut it out. Use EM a bit smaller then the part you are dealing with.

Nope, a carbide EM doesn't touch it. A Diamond Burr worked and I think I have it all out now.

Most likely threads are junk anyways, no matter what you use.

I'm actually hoping to save them. But we will see.


If possible re-thread bigger. I would start thinking of a need to either buy or make a new part.

It might be possible to rethread bigger. That's tbd.
 
Top