MOPED ARMY

70cc kit with 21mm carb, #74 main jet, #55 starter jet i think.....its seems to be running a little rich and im going to get a smaller jet to help it out.....but ill be driving it and it will be running fine....but after a while it will start to miss kinda and bogg down...then is shuts off and i cant get it going for 30mins if at all.....ive noticed that there is a ton of moisture all over the carb......ive adjusted the carb and such to try and better it but no results. one of the times i took the spark plug out and it looked great....still wouldn't start for a at least 30 mins.... Will a new pipe help the rich issue.....help me plzz