2018 Yamaha TT-R50E, Start them young! Our littlest TT-R boasts big YZ styling, four-stroke power, a three-speed automatic-clutch gearbox - even push-button electric starting. Go ahead, play in the dirt. Standard Features Engine Air-cooled, 50 cc, SOHC, 2-valve, 4-stroke power plant produces smooth, novice friendly power that eases the new rider up the learning curve Convenient, push-button ele...