Clogged petcock? Is the fuel even turned on?Float improperly adjusted?
This is assuming you have fuel related issues. Have you verified that is the case by artificially fueling the carb with starting fluid or better raw fuel sprayed directly into the carb? Does this improve performance?
Edit: wait so it starts?!? And it runs, ridable?!
My girl had issues starting her blast all the time, and started easy for me. Finally realized it was her method to starting it not the bike. She would twist throttle repeatedly while cranking and this made it sputter. I simply give it a pump close throttle crank and it fires right up