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Discussion Starter #41
See if you can get a left-hand extractor-type bit in the hole. You could likely get a replacement case half for less than $600, if the cases aren't paired. Keeping the drill centered so as not to take out anything you don't want to remove is the big sticking point. A jig is a great idea if you can devise one.
Yeah, Ive got a cobalt left handed drill bit arriving in a day or two, I'll be trying that before anything else. I'll have my machinist friend try to fig out a jig for me, my machining experience is practically non existant (hence my current predicament). Thnx for the advice!
 

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Discussion Starter #42
Dremmel a slot deep enough for a slotted screwdriver and try manually backing it out? Also a bad idea?
 

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This might be worth a try if you can find a pair of snap ring pliers that would reach the broken
bit and engage the flutes of the bit it might just twist out counter clockwise.
Pliers.jpg
 

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Two things to keep in mind before spending money on machining the case. Heat - a small but hot torch heating first the drill bit to remove it and then the broken bolt. Heat as we all know, makes metal expand.
This expands the area around it also and after it all cools there is a little less contact with surroundings. Might take a few attempts (3-4), take your time with it ... heat metal (drill bit and bolt only) til orange, it's tough but avoid heating the case as much as possible. Let the case cool to the touch between heating attempts. Propane is not hot enuf trust me I've done something like this (and it worked).
Secondly after exhausting all repair avenues like Hammy said I'd buy cases on ebay for about the price of all this machine work. You'd have to take the engine down anyway, this would save time and money.

Does anyone know for sure if the cases are magnesium, I've heard rumors about this? Wouldn't want a magnesium fire on top of all this Mr. Chigurh sir...
 

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Please don't do anything with Dremel's, splitting cases to use a drill press, or using another bottom case. Cases are ALWAYS matched. You could split the cases and use a rigid set up on a mill or similar machine, but NOT a drill press unless you have a drill jig as described earlier. And no heat on aluminum over 350 degrees, it will weaken it. Aluminum doesn't glow red, it melts. The cobalt drill isn't any harder than the broken off drill, at least not much. It will have to be carbide to cut out the broken drill. Anything you do without a drill jig will run off to the side of the broken drill. If you supply me with your aluminum cover and some measurements, I will make you a jig.
 

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Discussion Starter #46
Please don't do anything with Dremel's, splitting cases to use a drill press, or using another bottom case. Cases are ALWAYS matched. You could split the cases and use a rigid set up on a mill or similar machine, but NOT a drill press unless you have a drill jig as described earlier. And no heat on aluminum over 350 degrees, it will weaken it. Aluminum doesn't glow red, it melts. The cobalt drill isn't any harder than the broken off drill, at least not much. It will have to be carbide to cut out the broken drill. Anything you do without a drill jig will run off to the side of the broken drill. If you supply me with your aluminum cover and some measurements, I will make you a jig.
Once again, great advice. I will stay away from heat then too, I wasnt sure what to go with anyways, as Ive only ever used a propane torch and the fella said that wouldnt be hot enough.

Real kind of you to offer to make me a jig! I'll see if my machinist buddy can manage it, and if he can't, I'll pm you and make the arrangements as per your instructions. Would the jig work with a hand drill?
 

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Yes it would work with a hand drill. I cant locate a left hand cutting carbide drill. So a 4 flute ball endmill should cut it out of there. just let me know what he says.
 

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Discussion Starter #49
Oh man, I have no doubt in your knowledge and experience level, no need to prove anything to me! Just grateful for the help and advice...I'm just antsy, and cant help but to want to try things out in the interim till my machinist friend can peek at it and hopefully apply your advice.

I should probably learn to standby better, it's what got me into this mess in the first place 😔
 

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Just my opinion here but I'd go with a threaded rod welded (not JB weld) in the hole and nut on the outside of the oil filter cover before I bought new cases. I think if your machinist friend can't get the job done I'd go the threaded stud route before blowing all kinds of money on cases and doing a complete engine swap. I also think with a good welder/fabricator you'd save money vs buying new cases.
 

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Discussion Starter #51
Just my opinion here but I'd go with a threaded rod welded (not JB weld) in the hole and nut on the outside of the oil filter cover before I bought new cases. I think if your machinist friend can't get the job done I'd go the threaded stud route before blowing all kinds of money on cases and doing a complete engine swap. I also think with a good welder/fabricator you'd save money vs buying new cases.
Yeah, I agree, a new case would be my absolute last resort...

I get what the other fella was saying with the cost of a case being less than the estimate I got of $600, but that estimate included the tear down and reassembly time costs at $125/hr.

I suppose I could save a lot of money by doing the tear down / reassembly myself, but I just wouldn't feel comfortable doing it.
 

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Thnx for the thoughts, I am concerned that my KTM dealer may not be able to resolve this for me. I'll start with KTM, and then go for the wild stealership ride from there...if they prove unfruitful, I'll start hunting down a good machinist. The defeat is kinda killing me right now...Im scared.
Take it to a machine shop first since they know many ways to fix it and are much better equipped and so will do a much better job than a moto dealer at a fraction of the cost.
 

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Well, I've made a real mess of things. First over torqued (barely) and one of the oil filter cover bolts and broke the head clean off leaving the rest of the bolt inside the engine case, flush with the rim (nothing to grab onto).

Tried using a speed out, didnt work. Tried drilling it out...got through with a cobalt bit, but still couldn't get all of the broken bolt out.

Sized up to a slightly larger titanium bit and it snapped off inside the hole...about 1/2" inside. Cant get the broken tip of the bit out, it's tight in the m5 bolt hole.

I think Ive ruined the threads either way, they'll prob need to be helicoiled or tapped.

Am I screwed? Should I accept defeat and just send it to a ktm dealer?

Thnx in advance.
If there are no broken parts or over drilled holes into the engine compartment you can clean hole thoroughly and epoxy a stud into the hole. Then reassemble cover plate and use a nut to fasten it.
 

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I have done a lot of thread repair .It appears you drill bit is broken off below surface height and is embedded into a broken stud .First thing I would eat out the broken drill with a carbide or diamond or dental type bit. Then I would get out a left hand drill drill bit and try to unscrew the stud. I would use a left hand drill bit the size of a Snap-on thread extractor in case it fails I could turn to the splined type extractor { worse case I have drilled a series of tiny holes around broken stud and pulled out steel then TIG welded the hole shut and shoot new threads. ]
 

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Discussion Starter #58
Well my machinist buddy came by and basically went through a lot of steps I'd already done...hand drilling, screw extractor, picks, hammer it a punch, left hand drill bit, wd40, aerosol contact cleaner, etc. He basically just went at until everything inside was pretty much disintegrated and flushed out.

Drilled and tapped it to m7 because the original threads were pooched.

Now I have a 1m rod of m7 steel coming that I'll chop down with my angle grinder, and use a nylon nut to cinch it closed (maybe a washer too, if I can fit one in). On the non damaged side, I got a nice zinc bolt to replace the soft m5x16 stock bolt. That should button it up and be better than stock as far as the oil filter cover goes...will hope for the best, and update once I have everything in place.
 

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This sounds exactly like something that would happen to me. I just changed the oil on my Duke today too and my first thought was of all the ways I could destroy those tiny little bolts. Glad you got it taken care of by the sounds of it.
 
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