It ws a nice day to play outside. The carburetor was still giving trouble.
It seemed the choke gave a constant flow of extra fuel, so as an experiment I disabled the fuel flow to the choke. Seems to work, though I'll wait a while before jumping to conclusions. If it does work I'll order a gasket and seal set for the HIF to rebuild the choke. Note to self: Hifs are great, but fit new seals as soon as they misbehave! Now the engine runs fine.