Spark Plug thread pitch / Back Tap repair???
 

I bought a back tap tool in order to repair my threads. I'm not sure if it's the right size since it was the only one they had in stock across 6 different stores.

18mm with 1.5 thread pitch is what I bought. Is this too big?

The thread pitch is 1.25mm. Thread diameter is 14mm.

Thanks!

It was going to take more than 2 weeks for them to order the right size, so I bought it from amazon and paid $30 shipping to get it here over the weekend (it was still about $8 cheaper this way). http://www.amazon.com/gp/product/B0014FGVVW

For anyone else who might be in the same situation, it took about 20 minutes (I went verrry slow). I wanted to make sure I got hold of the proper threads and didn't have the thing crooked.

Once I was confident I secured the back threads (and could thread it in and out easily by hand), I would gradually expand it and work it out, thread it back in, expand, work out.

I basically put the socket and an extender on to get a better handle on it. I used VERY light pressure when I did use the ratchet handle - otherwise I just used my hands to twist the socket/extension.