After a number of minor improvements like change color, directional signals front and rear and a bigger, brighter stoplight, Yamaha launches the R5-B 350 cc. The Yamaha R5 350 was in many respects the crown jewel of Yamaha’s continuing 2-stroke program. While it put out the same 36hp as the previous year’s twin, an increase in torque and other refinements meant it easily boasted the best performance of any 2-stroke Yamaha had ever made.