The saga continues.  New carb gaskets installed, now carb is no longer leaking.  Still can't get engine to start.  It ran briefly with choke engaged but was only a "half-assed" attempt and shut off immediately when throttle put in run position.  I don't know what to check next.  To recap:  carb is clean, solenoid is quick to open, spark is visible at plug, gas is gravity flowing, and flywheel is fully spinning.  I also shot a bit of carb cleaner into cold carb, but didn't help it fire.