It could be a number of things. First after trying to start it pull out the sparkplug to see if it is fouled by getting to much gas. If plug is dry or not fouled check to see if you are getting spark to the plug. You can do this by pulling the plug,connect it to the plug wire & hold the plug close to a piece of steel or even the engine block.Make sure you hold the plug with rubber handled pliers,so you dont get zapped. You'll have to look close to see if it sparks. If it doesn't get spark,check the plug,maybe you need a new one. If you still dont get a spark you may need to clean up the magneto with a wire brush or sand paper.Just make sure that when you reattach the magneto that you have just a minimum clearance between it & the magnetic spots on the top spool. P.S If it is flooded with gas check the float in the carburator to make sure its not stuck open,if so clean it out real good with spray carb cleaner. Hope this helps
Sean
December 2007