I am getting ready to install my EGT thermocouple and I was wondering what size drill bit is the best to use? Edge Evolutions instructions say you can use either a 5/16 or a 21/64 drill bit. Which one is a better option?

thanx, JLew

21/64" is the closest to the size of the 1/8" NPT tap, but a type "R" bit is the exact size... I've used all 3 with good results though, so you'll be fine with what ever bit you have.

21/64" is the closest to the size of the 1/8" NPT tap, but a type "R" bit is the exact size... I've used all 3 with good results though, so you'll be fine with what ever bit you have.

Thank you...Gator;)

Anytime.

Make sure you drill straight in and when you tap it, make sure the motor is running so that you don't get any chips in there unless you are taking it off the motor..

Also, drill a small pilot hole to start with.

I installed mine last week and used a 21/64. It worked great no problems