i just finished rebuilding my 93 elit 50 cc moped

and now i am trying to get it started the only way to get it to start is to get gas or starting fluid right into the cylinder. then crank it over and it will only start if the throttle is wide open and it will keep running as long as the throttle is open but as soon as i let off it will just die.
im not sure? should i just run it wide open for a little will and see if that gets it going? or what? i dont no if i should cuz i dont want to harm my new top end.
any ideas? carb is clean, any tips on engine break in?
thanks!