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The thing that is broken in this picture is the casing that the header exhaust bolt connects into to. Don't ask me how the &%$#@! this happen one of my friends that supposedly knew what he was doing was working on it. Will never let him near my bike again. Anyway does anyone know how I can fix this other than buying a whole new freaking head

IMG_0133.JPG

Edited by Maxoss

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Could have a welder lay a bead over it just to help support the cast aluminum there.

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Is it just the chunk missing, or is that a hairline crack I see running much further?

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14 hours ago, ossagp said:

Is it just the chunk missing, or is that a hairline crack I see running much further?

It's just the chunk 

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How deep do the threads go into the casting?  The missing piece may not be an issue at all.

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I think I would be really tempted to run something in and see how much further you could thread it with out getting into the oil galley or anything else that I can't see from here.  Then looking at red loctite or or something even more temp resistant to keep it there.  You haven't got much to lose.    An insert is possible,  again with a bonding agent if it was me.  I have everything to weld with,  but that would be my last shot at this point. 

It looks like it was way out in the threads the last time it was tightened.  Live and learn. 

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I haven't spoken to them (Edco in 25 years.  They had this way of milling the cast in crank pins out of the 79-82 xr500 crankshafts and putting in a pin and installing a carillo rod.  Still got one sitting here.  Great head builders and "thowing it away" was not in the vocabulary.  

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when I break friends shit they expect me to buy them new shit. I expect the same from them. a friend would buy you a new head/cylinder/

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On 5/9/2017 at 4:08 AM, Maxoss said:

The thing that is broken in this picture is the casing that the header exhaust bolt connects into to. Don't ask me how the &%$#@! this happen one of my friends that supposedly knew what he was doing was working on it. Will never let him near my bike again. Anyway does anyone know how I can fix this other than buying a whole new freaking head

IMG_0133.JPG

 

Yeah,  for all the things that get broken by "friends" and "Previous owners"  it seems like no one ever screws up his own stuff.  other than letting friends work on it in the first place.

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The stud was not threaded in deep enough. Use a bottoming tap to get clean threads all the way into the blind hole, then thread the stud in deeper. You should be good, I bet there's a lot of threads there.

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The stud was not threaded in deep enough. Use a bottoming tap to get clean threads all the way into the blind hole, then thread the stud in deeper. You should be good, I bet there's a lot of threads there.

need new studs, too? Threads don't look right...

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Cast aluminum is a serious bitch to weld.  You will need someone who really knows what they are doing to even consider fixing that.

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Avoid welding, that is a last resort. Just maximize the use of the threads that are left.

Typically the hole itself is deeper than the threads and a tap has a taper that leaves incomplete threads deep inside. Use a special bottoming tap or grind off the starting threads of a regular tap. This will cut full threads all the way to the bottom of the existing hole.  You can also grind the end of the new stud if it looks like the one in the photo. Notice how the stock stud is tapered at the end, rendering the first few threads useless. 

The whole point is to get more threads engaged and you have plenty of room to do that from what I see.

Check the other side to make sure that stud has good engagement too. in fact do the same to that side.

You can buy metric bottoming taps and studs here.  www.mcmaster.com

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That stud shouldn't have come out of the head, looks like it was dodgy before your mate got at it.

As said by a few others, a NEW stud wound all the way home BEFORE the nut is installed should fix it. I'd use a permanent thread locker too. On the stud, not the nut lol.

Edited by DEATH_INC.

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Remove the nut from the stud, clean up the threads in both the head and the stud, then screw the stud in until it bottoms.  The problem was that it wasn't threaded deeply enough into the head to begin with (note the position of the nut on the stud; it should not be run down to the bottom of the outer thread like that).

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