It just stoped but will not start again

Hi, if it cut out whilst running it has either ran out of fuel or ignition. Please make sure you have plenty of fuel in it. This sounds like an ignition problem. Take the plug lead off the spark plug and stick a metal blade screwdriver into the end of the lead, then hold the screwdriver close to any piece of metal on the cylinder head close to where the spark plug screws in and get some one to crank it over by pulling the cord and holding the throttle as if you were trying to start it. You should get several sparks to jump from the screw driver across to the metal. If not you have a problem that involved a considerable amount of knowledge and stripping down of the engine covers etc to get to the offending items.