Hi Rich mine ran for 3 seconds and stopped on its first run. I checked for a spark by lifting up the rubber boot on the spark plug and pulling the ht lead out. Hold it near earth and turn the engine. Mine had no spark, the centre battery had popped out with the vibration. I put 2 elastic bands around the battery's and it then started. If you've got compression a spark and fuel plus the carb needle is open 1/4 turn it should start
Good luck Brian