I'm going to take a stab and say that there's a bit of dirt in there floating around the high speed needle. Best thing to do, remove the carb, take off the bottom and diaphram, pay close attention to which side is up. Some carbs have an "F" stamped on it, the diaphram on those has an indent on the metal rivet holding the washer on the bottom side, on the top side, it's a nipple shaped bump, that's the up side. Then remove the one or two adjuster screws, high & low speed(depends on the model). Take out the lever and needle from under the diaphram. Wash the carb in laquer thinner and blow it out with air. Assemble everything back together. If yours is a 2 screw model, replace the screws all the way gently, don't over tighten, back the right one out 1 1/2 turns, the left one about 1 turn. If it's a one screw model, back it out 1 1/2 turns. Start it up with fresh gas and add a bit of Seafoam, it's probably the best, anti gumming and cleaning additive. Once you have it running, let it warm up, if it's a one screw model, you can only adjust for high speed, keep it a bit on the rich side(counterclockwise), idle is adjusted with the set screw on top of the linkage. On the two screw model, the left screw is used for idle adjustment, idle speed is done with the set screw on top of the linkage. The auger should not turn at idle. When it gets real cold, you may have to open up the high speed needle a bit more. Good luck.
