Exhaust Bolt Broke Off

[Smokinapankake]

Common household ammonia will attack the alum. surrounding the bolt, thereby breaking that bond. Don't use too much though.

http://sheldonbrown.com/stuck-seatposts.html

This article covers removing a stuck aluminum seatpost out of a steel bicycle frame, but the principle in step 13 (or XIII for those who can't do the conversion) applies here also. Steel bolt on aluminum head. The trick is getting that ammonia down into the threads, where the bond occurs.

I've used this on my 84 Kat with reasonable success...

 

[Guest]

well, it still wont budge and im not pushing it-i dont want the extractor to break. How difficult would it be to replace the part? I wonder if id be more cost effective. What parts would i need? Thanks,

A head............

 

[djg42]

if i replace the cylinder head will I have to take the whole engine out or can I leave it in?
THANKS

 

[Billy Ricks]

if i replace the cylinder head will I have to take the whole engine out or can I leave it in?
THANKS

You don't need a new head. If you can get a drill in the right spot just drill and tap as already recommended. A tap might cost you $10 at the most. You can check the length of the other bolts and put some tape on the drill bit so you drill to the right depth. I broke one off on my bike and drilled and tapped with no problems. Since then anti-seize compound on the threads every time the exhaust comes off.

 

[djg42]

Thanks everybody, i decided try and drill it out and retap it before i spend a couple hundred having someone else do it. The bolt is 8mm, 5/16 inch. On the re-tapping tools some say a thread per inch. Do i have to find a certain thread per inch, or does it not matter?