the new MotoTec Phanton 49cc Gas Powered Pocket Bike! Standing in at 23 inches in overall height, this tiny monster packs a punch with a 2-stroke 49cc engine. Originally made for adults to race crunched up on tiny motorcycles, pocket bikes have now become popular with kids because of their small size. And you won't find a wimpy 4-stroke engine on this model, this 2-stroke engine delivers almost twice the power.