Well for anyone that read my other thread about the compression tester getting stuck, I got it out! I got the hose end off with 1 easy-out & the adaptor itself with another one. What baffles me is that the adaptor did NOT come out easily. It came out making all kinds of noise like it has been an old rusted bolt. I'm wondering if it could have been cross-threaded but I doubt it because it went in smoothly by hand. Anyways, I tried putting the old spark plug back in (they only have a few hundred miles on the plugs) & it won't go in very easily & I wasn't going to force it. I'm going to run a tap down the hole to clean it out but I have no clue what size I need. We have some here but nothing near the right size. I'm guessing that if the threads have been screwed up somehow that I'll have to cert it. Any suggestions or info?