The meetering needle is not seating. That is the only reason why a carb would be leaking fuel. In order to compensate for this the engine operator has leaned the engine too much. A very reasonable action if the bulk of his experience is with glow motors. Take the carb apart, blow out everything with carb cleaner, reassemble with factory needle settings and use a high quality filter between the tank and carb. Fill the tank before the filter.