Customers can choose between the 2007 Piaggio Fly 50 or the 2007 Piaggio Fly 150. The Fly 50 is named after its 49.9-cubic centimeter (cc) displacement, which is rounded up to 50 cc. Similarly, the Fly 150 is befittingly named after its engine displacement of 150 cc. The engine on the 2007 Piaggio Fly is a four-stroke single-cylinder engine that generates a little less than 12 horsepower at 7,750 revolutions per minute (RPM) and 8.5 lb-ft of torque at an RPM of 6,000. However, the engine on the Fly 50 (labeled the Piaggio Leader) has a bore and stroke of 1.5 by 1.6 inches, while the one on the Fly 150 (labeled the Piaggio Hi-Per4) has a bore and stroke of 2.5 by 1.9 inches.