Thanks guys, though it's not new stuff, just long winded

Oh, something I forgot, not all needle valves are created equal. Different hole sizes and tapers and ratchets make some needles much more sensitive than others. For example, the Magnum .15s that I run in combat are known to have really really REALLY sensitive needles. I mean 1 click is too rich, 1 click is right on, 1 click more is too lean. (it doesn't help that I'm pushing the engine for every last RPM I can get out of it). A lot of combat guys using Mags will actually buy an OS .15LA remote needle and put it in line before the Mag carb to make it easier to tune. Sometimes this silly of a thing is the difference between a beginner friendly engine and a real beast. I've never heard a good reason why any engine company has a blunt, sensitive needle, but they exist. Go figure.

And, of course, I totally left out anything to do with low end, but that's for another day

Oh, and while I mentioned the light color of oil coming out in a rich run, I forgot to mention that if you go over lean, the oil coming out will get really dark carmel or brown in color as some of the synthetic oils start to burn. Black gunk coming out the exhaust is a bad thing. Usually, it's fine metal particles. 9 time out of 10, it's coming from a loose muffler, or muffler tail cone, but if it's coming from inside the engine, the engine is wearing itself in a bad way. If you put your finger in the oil and rub your fingers together and see particles or feel grit, your engine is about to be toast. Of course, the exact color of the oil in the exhaust will vary with fuel brand and other factors, so it's not a percise measure of anything.