I was taught to use the pinch test by allowing the engine to warm up a bit then running up to full throttle and holding it there for a few seconds to clear out the engine. I then run it back to idle for a few seconds, then back to full throttle. That's when I do the pinch test and set the idle always working to rich and back to a tad bit leaner. I never leave the engine in a tune point where it is lean. I check it a couple of times, even to the point where I put it to blubbering rich for a moment to make sure that it's set right.

When I start out, the high speed needle was originally set to about 2.5 turns out from full closed, which always has been appropriate for the initial start and a good starting point for the tune.

I have use a pinch test at low speed, but not often. I use it mostly at high speed and, with a good practiced ear, I seem to get it right.

CGr.