Moped Army

Recently i had some carb troubles. so i rebuilt it and got my engine to start again. the trouble now is when i pull the throttle from standing still. the engine will bog and die. if i pedal the bike before giving it gas then it will pick up and go.

i did a plug chop this evening and it looks good.
i just redid the gaskets.
I am fairly stumped as to what it could be.
any ideas?