Go to the basics if it will not restart, check fuel and spark. Grab it by the ears and look down the belly of the beast (down the carb ) pull the throttle lever back a couple of times and see if it's squirting fuel. If it is than pull the coil wire off hold it ( not your hand ) about 1/4 to 1/2 inch from the intake manifold or a bracket. don't use the valve cover, and see if you have spark.