I now have the bike starting easily on the choke and idling smoothly. I still cannot get it to idle without the choke. I’ve tried playing with the air screw, but it doesn’t seem to have much effect. I am left to suppose that either the float height is low, or the pilot jet is too small. I’ll have to continue playing with it.
In order to feel some sense of accomplishment, I also filled and bled the front brake. (brake line vacuum pumps are a stupendously wonderful tool to have, BTW.) I rolled it down a hill in the yard and it stopped the bike firmly at the end of the driveway, keeping me from rolling out into the street. So, that’s a win.
Since there really aren’t any meaningful photos to document any of this, here are a couple of general progress photos: