I got this motor about two weeks ago and it of course did not run at all. So i went ahead and rebuilt the carb, replaced fuel lines, spark plug, and gaskets. The motor will now start on second or third pull but will only run for about thirty seconds to a minute and then shuts off. It is getting plenty of gas and the impeller is working. Does anyone have any idea what it might be? Any help is greatly appreciated. I have about torn my shoulder out of socket because i have pulled the cord so much.