ZL600 #1 plug fouling

I replaced spark plugs yesterday, prepping the bike for a trip to Gettysburg bike week. During a 3 mile test ride, the bike idled poorly and stalled out twice. I checked the plugs, and #1 was black. I decided to put the old plugs back in, went for a short test ride and once again, poor idle and  #1 plug is carbon fouled black. Resistances through plug caps, wires, and coil is good. #1 plug is giving a crisp blue spark.