Yamaha YZ450F - First Generation: YZ400F - 1998-2000

1998-2000

Yamaha introduced the YZ400F in 1998. It was "the first modern production four-stroke motocrosser that was directly competitive against two-strokes." Initially, Yamaha targeted a dry weight of 233 pounds (106 kg) (on par with the 250 two-strokes of the time), but by production, the bike weighed 250 pounds. The bike had an 11,600 rpm redline power and torque close to its 250 cc two-stroke rivals. It benefited from engine compression braking, which allowed the engine to slow the bike down during deceleration, giving the brakes a rest.

Though the YZ 400F had a wider powerband than its two-stroke counterparts, the bike had some problems. It would stall far more easily than two-strokes, and had a very difficult time starting.

In 1998, Doug Henry won the AMA National Motocross Championship aboard the YZF, becoming the first rider to win a championship on a four-stroke motorcycle. This victory is considered by some to be the major turing point in the motocross world—for the first time, four strokes were considered a competitive racing machine.