▪ Yamaha introduced the YZ400F into production in 1998 after a successful AMA season in 1997
▪ In 1998, Doug Henry won the AMA National Motocross Championship aboard the YZF, becoming the first rider to win a modern-day championship on a four-stroke motorcycle
▪ The bike weighed in at 115kg, well above the weight of a 250cc two-stroke MX bike
▪ It was the first modern production four-stroke motocrosser aimed directly at competing against two-strokes
▪ This championship win turned out to be a glimpse into the future as the four-stroke, with its smooth, easy-to-use power delivery, became the bike of choice for both the racer and the everyday punter
1998 YAMAHA
YZ400F SPECS
▪ Engine type: Liquid-cooled 4-stroke, DOHC, 5-valve
▪ Displacement: 399cc
▪ Bore/stroke: 92.0×60.1mm
▪ Compression ratio:…