[quote]It ran great at first. 4,000 miles later, its blowing smoke (when its cold) and it hesates when I give it a little gas.<hr></blockquote>
It sounds like it is in the enrichment (choke) circuit. Does it clear up once warm? How is the idle quality upon start? Does it have a choke pull-off/unloader.
And again, we need to know what kind of carb you have. Year and model of vehicle will help also.