I used the snow blower yesterday and it worked fine. I wanted to clean up some drifiting. The snow blower started fine with electric start. However after just a few minutes it stalled out. When I restart it starts fine but as I use it, it stalls out. I put a full tank of new gas in it this morning. The oil is fine. There is some black soot / color by the exhaust. If you try to open the choke it begins to stall. Any thoughts? Thanks.