A couple other things to check:
Be sure the gas tank is vented. Try running with the cap off just for a test.
Not sure about that carb, but some the venturi can be installed upside down, that will cause lean running, hold the bowl away from the top so no idle.
To adjust the main, with the engine at idle and warmed up, the engine should take sudden full throttle without hesitating. Keep opening the main until it responds quickly, a single puff of black smoke is desirable.
Back to the ignition, be sure the distributor shaft doesn't have side play, and the centrifugal advance is free. Try the old condenser, new ones are known for being bad out of the box.