Simple question, I need to know the tap size to clean up a couple of my spark plug threads.

 

TTT

 

Alright, alright, enuf already. The plug thread is 14 X 1.25 mm.
Ah, just a suggestion. If you are gonna use a tap, be damn careful that you do not remove aluminum/metal with the carbon/crap. You can very easily end up with a sloppy plug hole. Safer to use a plug thread chaser made for cleaning plug threads. I know KD sells/sold one.

 

I just picked up a spark plug thread chaser that has 14mm on one side and 18 mm on the other side.

 

The K-D would be a #730 I believe. Ah, waiting for a response? Yes, 18 on one end, 14 on the other.