Many small engine carburetor fouling problems can be avoided by proper use and storage procedures. Since use of a snowblower is weather-dependent, it can go extended times between uses. At the very least, one ought to use stabilizer in the gasoline. If the gasoline container isn't emptied often enough, put into your car's tank; that will be used regularly. Get fresh gasoline for the snowblower at the start of winter.
If possible, use ethanol-free gasoline for small engines. Look here for locations where it is available:
https://www.pure-gas.org/extensions/...p?statecode=NH The closest to me is the station on rte 25 in Moultonborough, just east of Redding Lane, although the map on the referenced site shows it (incorrectly) as being farther east on 25.
At the end of each use of the snowblower, turn off the gas supply valve and let the engine run out the fuel in the carburetor. However, not all snowblowers have a shutoff valve, so it might be useful to drain the carburetor manually. I had been having enough problems with my boat engine's carburetor that last year I finally installed a shutoff valve. When I go to pull the boat at the end of the season, I close that valve as I approach the shallow water near the ramp, and the the engine runs out the fuel in the bowl. I also have taken to using ethanol-free gasoline in the shoulder seasons, when the boat isn't used much. Still, I add stabilizer to the tank in the fall.