Spark plug adapters

I'm trying to connect my compression gauge to the engine of my 1983 GPz 550, the problem is that the smallest connector for the gauge is for 14mm spark plugs and the GPz 550 seems to take 12mm ones.

Soooo ... does anyone know a good place to buy a simple 14mm - 12mm spark plug adapter?

I've seen a few websites which cover making one out of an old spark plug, but they shouldn't be too pricey to simply buy, right? I mean a Snap-On one only runs ~$18 ( buy1.snapon.com/catalog/item.asp?item_ID=75283&group_ID=19865 ).

Thanks

try your local NAPA store. They have a lot of tools still. Or maybe another larger Parts store such as PepBoys. Should be 12x1.25mm, for the head.

I found out the hard way about that too but I used a tire vavle from a car and removed the inner valve and just press down the sparkplug hole and press the compression tester against the hole.

old thread but I can bite, being poor I made my own, took a 14x 1.25 nut, welded it to a short piece of pipe, then welded that to the end of an old 12mm spart plug. vacuum tested for leaks, added a few o-rings and done, total cost. just wire and gas.