Why wont my moped start?

So far i cant disagree with anything said it sounds like fuel or spark problems. As long as you haven't messed about with carb settings before it has to be either blocked jet or starvation along the line. Just a thought have you checked to see the spark is strong at the spark plug. Finally have you cranked the engine several times and checked to see if its flooded( smelling of fuel) you can whip the plug out and see if its soaking wet. When you say it starts is it responsive and revs up or is it choked and muffled? Just thought make sure carb is bolted on firmly I did have a 2 stroke that the carb became loose on and never ran well.