Sounds like no fuel or no spark.Try kicking it about 5 or 6 times just as you would to start it.Then pull the spark plug and look at it.If it did not start or backfire the plug should be soaked with gas.If it is not then check the fuel system aka dirt in the tank or carb or something else stopping the flow of fuel.If the plug is wet then check the spark ,put the plug back in the cap and have someone hold it with insulated pliers so that the threads are touching the motor,kick the machine a couple of times you should se a nice fat spark jump across the gap at the end of the plug,If no spark look for loose or unplugged wires on the coil,on off switch,CDI.If you have spark and fuel it should fire may not run but you should at least hear it try to start rather than just rolling over.