It seems like if you've replaced the carb, cylinder head, piston, ring, crankcase, spark plug, ignition, hall sensor, and reed valve, that you are not even working on the same engine that you started with.
One thing that should have been noticed when you replaced the crankcase and the bearings and the only thing left that I can think of that is left from the original engine is the crankshaft key.
The woodruff key may be sheared. You can check the timing with a good piston stop and degree wheel. Since you get a pop, that means you have fuel and spark, but maybe not at the right time.
If that is not the problem, it would be a good idea to pressure test the engine and looks for leaks.