My buddy picked it up to use yesterday.....I was just using it Tuesday. He got it to his house, and it wouldn't fire.....put in a new plug....it's getting Air, Spark, and fuel, and gives a slight backfire at the end of a pull on the rope....not even close to coming to life. We figure one of two possibilities....key way broke, timing off....or bad gas, which is unlikely IMO, he just ran some thru his mower without a problem, although this gas was bought earlier this summer. It's at the shop, bought it 1/16/2012, might be warranty, not sure....anyone care to guess whats up ?