I'm real curious about the inside rim of the plug specifically, if you can tell anything by looking at it as opposed to just reading the insulator and tip/pipe? If the insulator is bone white, the electode slight grey to bare, but the inside rim (metal portion) is black what does that indicate? I just richened my needle back to the stock position and it doesn't seem to be running as clean as when I had the needle 1 step leaner however, I get the above plug reading which makes me think I'm too rich in one area and maybe lean in another. Oh, the reading on my pipe (outer tip and inside the throat of the slip on is greyish. Thanks!