i have the 2000, never any trouble, but i always run premo and add seafoam to all my small engines. i'd change gas filter and dump old gas and start over.
I have a em2500 and did see that problem , only seemed like a problem when it was higher humidity = snowing... maybe gas was the issue.. may have to try .dont use too much now as use mainly 12v.
I do run seafoam allready. The problem is it ices up right where the carb meats the airfilter housing. The venturi keeps shrinking in diameter until it floods out. I have now built a hot air induction for it. Hope that helps. Thanks for the help.