check for fuel, ignition, compression. take the fuel hose off at the carb, be sure fuel is in the tank, take the pressure line off the exhaust, blow in the pressure line you should get fuel out of the line going to the carb. now when you spin the engine, if you cover the exhaust pipe the fuel should go into the carb. check the glow plug by putting it into the igniter, do NOT use pliers to hold the plug it will mess up the threads and mess up the head.