I would think that it is a small pc. of crud in the carb on the idle section or could be the float is not set right, even a spec of crud on the idle screw or the seat will not let the fuel flow evenly because there is no presure pushing the fuel , when I rebuild a carb I use toothpicks to clean all the jets and a good carb cleaner I make sure that all the ports are polished up and same with the mixture screws and jets some 4/0 steel wool and toothpicks will get everthing polished up and get You a good running carb.Check the ht. on the float to.


Pete