Broken Exhaust Stud/Head Removal

[lrholy06]

Wow, thanks guys. You're all very quick to help a guy out. Oh and by the way, its the front. But now I am thinking that would take me quite a while to get done. Projects like these always seem to take me a lot longer than most of you guys.;)
Anyway, maybe drilling it out wouldnt be too bad. I think I have enough threads on the one side to get one of those stud drill guides on it. Would it be better to just drill it? or take it apart? And if I did drill it out, how do I remove the threads? is that what the tap and die set is for? I have not ever used one of those. And are these studs actually IN the engine? wouldnt chasing the threads out just push them into the engine?

[konarider94]

when you drill the stud out it does leave the thread still in if you drilled it right. then the tap will try to cut what is there and will probably bind with the left over thread material as it gets pushed out of the female threads. when i had to drill mine thats what happened. when i backed the tap out i was able to grab on to the left over thread of the stud with a pair of needle nose and pulled it out in one long piece. it was pretty cool and i was pretty impressed with how centered the drill was, it was like grabbing the thread off a bolt and unraveling it if that makes sense. the aluminum threads of the head were completely undamaged in my case. the drill jig is pretty thick, you really need a whole stud to use it properly. i suppose you could try and use a small piece of stud as an alignment pin and maybe use a c clamp to hold the jig to the jug securely. then once one side was drilled out you could fasten it like designed for the other side.

another possibility if you have a piece of stud sticking out is to weld a nut to it to try and wrench it out. spray it with kroil too. the heat from welding will sometimes help it break loose.

[Timeless]

If the studs up front are exposed, get one of the drill guide jigs, and drill the studs out. Take your time and everything will be fine.

I recently repaired a broken stud in my bolt and I used this drill guide: http://www.ebay.com/itm/390453158726

After you drill out the stud, chasing the threads will break the remnants of the stud threads away from the threads in the head. This should be done slowly. Take the tap out after a couple turns to clean it and clean out the mating hole in the head. If you get lucky, a bit of the thread/stud will be exposed from the head after it is drilled out. You may be able to grab it with pliers and pull most of the stud threads out.

The studs are threaded into the engine and are removable (unless their corroded in). Chasing the threads will not push the old threads further into the motor.

[squidbuellie]

i would like to make some thing clear...
if you are a perfectionist, then to do it right, you will want to drop the motor pull the head.
then replace the head gasket, base gasket, valve cover gaskets, head studs and head bolts.

but most people, including harley would pop the head off, scrap the head gasket off the bottom of the head replace the $4 head gasket.
then clean the valve cover gasket and reuse it, toque the heads and call it a day...

just remember to clean the studs and then use a dab of oil on the head threads and instead of torquing it a 1/4 turn do it 1/2 for the final toque. the head studs are spring rods so used ones are stretched a little.
good luck.

[crawfo]

So one of your studs is broken flush with the head and the other is broken at the nut on the treads? I would make an attempt to get the one still sticking out, out first, then use a new stud to use the jig on the other. I wouldn't be scared to weld a nut in place on the stud that is sticking out, or you can use the double nut trick. I personally think that with it being your front exhaust studs it would be easier to do it with the head on.

Just my 2 cents

[lrholy06]

Well I think I will try that first. Thanks Crawfo. If that doesnt work then I will take it down and change everything out. I dont know if I have enough threads on the one side to double nut it, so I may have to weld a nut on there. What needs to be disconnected prior to welding to save the electrical side of the bike? I dont want to cause more trouble for myself.

[wolfo68]

Disconnect the battery if you're nervous about it, but you should be good. I've watched a guy weld a nut onto the stud with only taking the header off. Not something I would've done, but it actually worked without harming anything.

[crawfo]

Most people disconect the battery when welding on any vehical, but i never have, and have never ran into a problem. If you want to be safe disconect it like wolfo said. Keep us posted!

[konarider94]

i would like to make some thing clear...
if you are a perfectionist, then to do it right, you will want to drop the motor pull the head.
then replace the head gasket, base gasket, valve cover gaskets, head studs and head bolts.

but most people, including harley would pop the head off, scrap the head gasket off the bottom of the head replace the $4 head gasket.
then clean the valve cover gasket and reuse it, toque the heads and call it a day...

just remember to clean the studs and then use a dab of oil on the head threads and instead of torquing it a 1/4 turn do it 1/2 for the final toque. the head studs are spring rods so used ones are stretched a little.
good luck.

You have to replace the base gasket, there is no way you would not upset that seal. No shop would simply throw a new head gasket on without touching the base gasket.

you seem to be eluding that these studs are torque to yield fasteners, can anyone else confirm this? I have never heard that before and the manual doesn't say anything about this. I've had my top end off 2 times and have reused the studs. Just because they use a final torque with a degree rating does not mean its torque to yield. If they were and you went 1/2 turn instead of 1/4 turn the torque would be much higher, once you pass the yield point the bolt will start to work harden. 1/2 turn of stretch on a harder bolt would be significantly more clamping force than 1/4 turn on a softer bolt. If it is in fact a tty stud you would definitely want to replace them but I don't believe they are.

With aftermarket gaskets they list the final torque at 42 ft lbs instead of using a degree based torque spec.

[EricZ]

Of the 4 years I worked at a H-D/Buell dealer, we always replaced base gaskets if the heads were removed. It is too easy to pull the cylinders and replace the base gasket and would cost twice the time/money if you didn't and the old base gasket leaked after the job was completed.