If you have a automotive style compression tester that did not come with the adapters needed for M/C plugs (as was the case with me) I found some adapters. They fit my Craftsman Comp tester, and were similiar to the one adapter that came with it. Worked good, and saved me a little $$ not having to buy a whole new set with the correct adapters.
It comes with 3 adapters, 10mm, 12mm, and 14mm.
"Equus 3618 Adapters for Compression Testers"
I got them on Amazon, $9.91 / $6.17 shipping.
