How did you clean the carburetor before installing the rebuild kit? The fact that it ran well for a while tells me some crud that was not removed properly prior to reassembly had gotten dislodged and is clogging up a passageway somewhere. Unless every hole, passage, and assembly is pristine clean, installing a kit is futile. Soften the deposits however you choose (Jon recommends boiling in a solution of Dawn dishwashing liquid and water) and then use massive of volumes of high pressure air to blow the passages clean. If you aren't willing to do things that way, you're wasting your time "rebuilding" the carb.
Jerry
