the sparkplug threads are cream crackered in the 2cv heads (we are reconditioning them , for the lomax special)
they,re off of the engine btw
we have ground the valves in and replaced the seals at the top of the guides
are the helicoil kits any good?
maybye there is a better alternative
thanks for any suggestions fellas
andy

I had a plug blow out on my 1962 BMW 500 bike many years ago. I had an engineer put a steel insert in which was retreaded to take the plug. It was a lovely neat job, but it caused me problems with he heat range for the plug on that cylinder, as soon as it go really warmed up it misfired like hell. I only managed to cure it with a plug from my Kart racing engine!!! Mad or what? Helicoil is the way to go in my book or another head LOL

good advice banjo, thanks

ayjay,
I've used Helicoils for repairing spark plug threads and had no problems with them.
Just be sure to follow the instructions, especially about making sure that the coil is set 1/4 to 1/2 turn below the surface of the alloy.
I've found others which have failed and the reason was that the insert had been left flush with the surface...
http://www.repairengineering.com/helicoil.html

ken

I've heard good things about Timesert thread repairs:

http://www.youtube.com/watch?v=Gxnm8J9WXz8

http://www.youtube.com/watch?v=pLVDb0xcvMo

Used them twice, never had a problem.

thanks averyone helicoil it is
i,ll take your advice on the thread lenghth ken