I have a 6.5HP Briggs motor on a crafstman 21 inch that my neighbor left out all winter in the rain & snow. I'm trying to get it running. I am to the point where if I prime the engine it will turn over but then stall out once in uses the gas I primed through (2-3 seconds.) I know next to nothing about engine repair but thought this would be a nice little project to learn on. Any ideas what I should try next.