first of all, make sure u have gas in it, the engine cut off switch is on "run", the fuel is on, and turn on the chock. If it still dosent start make sure the battery is charged. If it still dosent start youll prob need to change the spark plugs. I had this problem.. to make sure this problem never happens again make sure you warm up the bike. Dont turn it on, rev up the engine so ur friends can listen to it, and then turn it off. Youll fry the plugs. More than likely youll need to change the plugs. Good luck