March, 1998

Forget everything you know (or have heard) about 4-stroke race bikes. We've got news for you: the new YZ400F. It's the most radical production 4-stroke ever produced. In fact it's different from any production 4-stroke you've ever seen. And it's 100% motocrosser. Power comes from a revolutionary liquid-cooled 400cc, 5-valve, dual-overhead cam dry-sump engine. It actually delivers more horsepower than 250cc 2-stroke machines. What makes this bike unique is the way it delivers power. It has far less rear wheel spin...which helps it accelerate quickly...and it's FAST! The YZ400F delivers tractable power that's readily accessible, allowing you to take rock-hard tracks...or pull through deep loam without bogging down. In fact, the power characteristics of this engine are such that it requires less shifting. The engine is narrow--slimmer than some 2-strokes--so it doesn't get in your way during extreme maneuvers. And it's as light as a feather. The YZ400F is the lightest production 4-stroke motocrosser currently available. As a matter of fact, it only weighs a few pounds more than the YZ250! Plus it shares the same basic frame geometry--and suspension. The YZ400F uses different spring rates and damping, carefully selected to match the power out of the 4-stroke racer. In the meantime, forget what you know about 4-strokes. And start thinking about fast, light and agile.

Information provided by Yamaha