...I was heading for the gas station when I realized something was wrong, and then I counter-realized that something was right: I wasn't worried about being pulled over because I was 100% legal for the first time.
Problem: the bike now leans out at higher RPM, meaning that I didn't need to touch the carb yesterday. So tomorrow or Sunday I'll put it back where it was.
The thing is fine at lower RPM and only leans out as engine speed climbs, which means that the idle circuit is too rich and the rest of it is fine. I'm also going to have a very, very close look at the choke and make sure it's working correctly, because if the plunger isn't returning to the bottom of its bore that would make things too rich.
I thought it was too rich only because the bike starts so damn easily and runs without the choke on even when its cold. From stone cold I need to use the choke only for the initial start; and after that it runs fine.
...so the idle circuit is too rich and the rest of it must have been okay before I got my dick-skinners all over it again. Fix the idle circuit mix, and put the main needle back in the middle, and I expect that the bike will actually have enough power to get moving from a standing start without me slipping the shit out of the clutch. And it won't misfire above 2,000 RPM because it's starved for fuel. WTF.
Anyway, I got the "M" today, and I had my first ride. As planned, I rode to the corner gas station and filled the tank; it cost me $4 to add one gallon to the tank and I feel like a real motorcyclist now. Heh.