Can't get it started

If you didn't have the dizzy out I would do a quick compression test.Or with a helper cranking it, check for suction at the primaries, with the secondaries plugged and the spark disabled.
I've seen a couple of engines jump the chain during cranking.
If the rings don't seal well due to fuel wash,compression will be low, and more importantly, so will carb-suction.It takes suction to pull a burnable charge.
A few CCs of oil can restore ring seal, due to fuel wash.
(Yeah I know it's not really pulling the charge, but everybody understands the concept.)