YZF, becoming the first rider to win a championship on a four-stroke motorcycle. This victory is considered by some to be the major turning point in the motocross world—for the first time, four strokes were considered a competitive racing machine. Second generation: YZ426F 2000–2002 In 2000, Yamaha updated the YZ400F, increasing the displacement to 426 cc for greater power and throttle response. In addition, the carburetor and jets were updated to ease the YZ400F's starting woes. The next year, in 2001, Yamaha replaced the previous steel valves with titanium ones. The new valves were more than forty percent lighter than the previous valves, allowing for lighter and softer valve springs, in turn allowing a quicker revving engine, improved throttle response, higher rev ceilings, and more power. The crankshaft was also reshaped and the whole assembly was redesigned for quicker throttle response and, Yamaha claimed, "less high-end horsepower loss." In addition to motor modifications, a few changes were made to the transmission to help contain the power and ensure longevity. The suspension also received a bit of an overhaul with the goal being reduced weight and smoother action throughout the stroke. Yamaha also designed a new exhaust pipe design so that exhaust header removal would no longer be required when replacing the oil filter. Carburetor tuning was modified to deal with starting and off-idle take off difficulties. Also in 2001 the subframe was changed from a steel to a blue painted aluminum style. In 2002 the blue painting was stopped and left to a bare aluminum look. Motorcycle.com says that "The gas tank is reasonably thin and allows good forward and backward movement while providing something nicely shaped to hold onto with your knees. In fact, the entire ergonomic package on this YZF is well thought out. The handlebars have a nice bend to them and are well-placed for good rider control and legroom. The footpegs are well-made units with a wide platform and sit in a position that keeps them from dragging in ruts without cramping a rider's legs." In 2002 Yamaha remapped the digital CD ignition system which delivers a more precise spark and optimal timing for faster, stronger response during hard acceleration, and less kickback during starting. Also an all-new swing-arm which is lighter and stronger for reduced weight, greater rigidity and more compliant rear suspension action. While an anodized finish gives the bike a tricked out look.