2002 Yamaha PW50, PW50 - The smallest Yamaha playbike uses a mild, 2-stroke engine with a simple, single-speed automatic transmission. The 49cc engine is mildly tuned to deliver predictable power that gently eases the new rider up the off-road learning curve. It s equipped with exclusive Autolube oil injection that eliminates the need to premix fuel and oil. The PW50. The perfect beginner bike!