spark plug thread size

[honeybadger]

Howdy guys, I can't quite tell what the thread size is on our spark plugs.

Need to know because I need to buy a leakdown tester and need to have the proper adapter (obviously)

[oldktmdude]

Howdy guys, I can't quite tell what the thread size is on our spark plugs.

Need to know because I need to buy a leakdown tester and need to have the proper adapter (obviously)

Thread diameter is 12mm, thread pitch is 1.25mm and the reach is 19mm.   Regards, Pete.

[bigbore2]

or you could do what I did and buy a leakdown/compression tester [I am assuming they are the same?] with a 14mm end thinking the mm designation would be for motorcycles because it is millimeters and an auto designation end would be American units.  then when I tried to screw the tip in it would not fit and I spent WAY too much time trying to get that tip to fit before I realized it was the wrong size.  Yep, now I need to get an adapter also.  14mm to 12mm.
That should not be too hard to find, eh.

[movenon]

Me to.... http://www.toolsource.com/adapter-clt2-compression-tester-14mm-12mm-p-100140.html this might work ?

[bigbore2]

thanx movenon.

[fj11.5]

I used an old spark plug with the center ripped out, welded an air fitting to it, and works great for leak testing and compression tests