Stripped exhaust threads, how do you fix them?

[oldtime]

I made an oversize tap and cut new threads same pitch  . Made oversize nuts  !! Ask Pete roper it was for a friend of his .

[Kiwi_Roy]

I made an oversize tap and cut new threads same pitch  . Made oversize nuts  !! Ask Pete roper it was for a friend of his .

That's a great way to go if you have the machine and the skill to use it.

On that note didn't one of the suppliers used to sell oversize nuts that would cut their own threads?

[Tom]

Don't forget the exhaust gasket that goes between the the head and the header pipe.

[Farmer Dan]

Don't forget the exhaust gasket that goes between the the head and the header pipe.

Have a pair on my bench already.  Waiting for payday then I'll order all the "stuff" I think I'll need.  Gaskets, O-rings, locking nuts, etc.

[Tom]

 

[JoeW]

Well I guess that settles it then.  I want to keep the bike as original as possible so if the head can be repaired then that's what I will do.  If it's that easy to put back on then I shouldn't have any trouble.  Once I send the head out I'll order new gaskets and exhaust nuts (with the keeper).

When you get the head back from Competition Cycles, please post a picture of the repair. I have an Ambo head in stock with a welded in insert, I don't know who did it. It looks like this...



Here is the repair done by my machinist...



 

[swooshdave]

Stripped exhaust threads are very common with Nortons. The nut gets loose and rattles around and destroys the threads.

Tighten when hot and you should be good.

There are several fixes out there for the Nortons. I've seen them welded up and recut, oversize nuts, inserts welded in and probably the nicest fix is an aluminum/bronze insert. The head is CNC cut to remove the old threads, and the new insert is screwed in. You can't see it when the exhaust is on but you know it's not going to cause you problems.

[Farmer Dan]

Any chance the insert they make for the Nortons would be the same size we need for our heads?
I've never had the pleasure of owning or working on a Norton.

[Farmer Dan]

The head is on its way to Competition Cycle.  I'll post some pictures of it when it comes back.

[Tom]

Nice doggie! 

[danedg]

It will look like this....


+100 for Comp Cycles!

Best deal I've found in a long time!

He said he can repair almost any brand.

[Kiwi_Roy]

my 72 had stripped threads as well

I didn't want to subject the heads to the stress of welding inserts so I converted them over to a flange arrangement.
Sorry, don't have a picture.