Thanks. 3/16 turn (left) made a difference, I think. Seems to run better and get a little better mileage, but that may be the "at least I didn't wreck it" factor. I'll let the carbon blow out for a few days and maybe readjust.
The running temperature actually dropped a little, according to the gauge.
I may need a higher thermostat.

I thought the lowering the fuel pressure would lean out the system.

The thermo/electric control pressure regulator, I thought, would keep pressure high while cold to enrich the mix. So, by bypassing the regulator and lowering the pressure below the CPR baseline, I might lean it out further. By monitoring the exhaust gas temp I should be able to tell if I'm risking valve damage. Sort of an engineering project.