HEY! well as luck would have it, diddling with the air mixture screw actually made a difference. I tell you, it's such a little thing, you'd never think. But I imagine because I have this homegrown airbox and pod filter setup, plus the report of the head and new exhaust, that you just can't go with the stock 2 turns out and expect it to work. I backed the screw out to 3 whole turns after starting and could tell that it was making a difference. My intuition said it would idle okay once the choke was off and it did. However I did recalibrate the idle as it had been set for when the fuel enrichener was switched on, which is too low when switched over to the pilot circuit.
Anyway, I was too giddy to not take it out for a quick spin up and down the street so I strapped on my helmet and leaped out into the street...luckily nothing horrible happened in the ensuing runs up and down the block --- just through 1st and 2nd. Jesus, the rear sprocket only has half it's mounting bolts attaching it to the hub. Banke must have left them in the bits box somewhere, i can't find them but they're easy enough to source.
My crotch-dyno says it is waaaay more oomph at the lower end than my XR650L. Just felt wheelie friendly. Stock 650L's are horrible off idle and even when uncorked, they don't ever yield an assured PULL when throttle is rolled on. With my hamfisted tuning, it seems like this bike's gonna do better than my L ever did. Sorry L:
Anyway, I couldn't resist breaking the rear wheel loose in our mulch project out back. Tried to capture the moment below, kind of like I envision a parent might take a picture and blog/facebook/twitter their baby's first turd.