I have the same motor and I also have to prime it to get it to start. Runs like a champ once it starts. first one I had I sent back to Horizon to see why it wouldn't draw fuel, and they couldn't get it to draw either and sent me a new motor. New one has the same problem, so I have learned to live with priming on cold starts with full choke. The plug has to be FILLED with fuel twice to start it every time.