Wasn't too hot. Eight in the morning, 78* F when I was running it. Here in the TX Hill country we stay in out of the sun in the summer afternoons! We retired folks, that is.
Just for an update, put the engine & fuel tank on the stand with the tank height set so that the centerline of the tank was even with the carb, ran it again. Still didn't run right, still had bubbles. I packed a bit of silicone grease around the HSN O-ring seal, reinstalled it. Engine ran better, no bubbles. Overall though, it acted like it had an air leak to the CC. Loosened the carb hold-down, pushed down hard on the carb, re-tightened the hold-down. Engine ran almost normally until it sucked up the silicone grease on the HSN & started leaking. So, found a new O-ring for the carb base (13mm ID, 1.5mm dia.), waiting for the HSN O-ring from NV; couldn't source it locally. Will run it again when the parts come in.
CR