You need a special tool.
They are not cheap, but they are less than taking it to a machine shop.
It's for chasing the threads.
You collapse the tool.
Insert it in the hole.
Expand the tool.
And then unscrew it out of the hole.
It gives new life to the threads and hopefully you can install you new spark plug.
I'm fond of KD brand tools.
The number for it is 3545
Monday, May 25th, 2009 AT 11:22 PM