Ok, go backwards………………pure and simple. If you remember these, you’re either gray haired, have no to little hair, or you’re sneaking bottles of hair coloring into the house! The year was 1971 and you are looking at Yamaha’s King. This was the BIGGEST and BEST Yamaha had to offer in road machines. It was the most powerful motorcycle in Yamaha’s catalog. This was it’s 2nd year production model. The previous 1970 model was a better and welcomed answer to the British 650 Twins of the Triumph and BSA. The superior Yamahas had electrics that worked, their crankcases horizontally split so they wouldn’t leak. Yamaha’s 650 Twins also incorporated 2 Constant Velocity carburetors (vacuum) for smooth deliver of the whopping “53 Horsepower” the XS and XS1B produced.