Well, I answered my own question.
Ran a foot or two of fuel line off a funnel hanging over the engine, direct to the carb. Runs perfectly.
The “screen” as Honda calls the part poking up into the bottom of the tank, directly attached to fuel manual valve, must be plugged badly..
I wish there was a more obvious inline fuel filter, I would have seen and replaced it preventatively. But at least I didn’t just buy a new carb, only to find that wasn’t the problem after all.
How many times do we have to repeat the mantra? Fuel, Air, Spark.