From its origins as Doug Henry’s 1997 YZ400F supercross race winner, the Yamaha four-stroke revolution has made steady progress over two decades. For 2016, the family tree branched out to include the YZ450FX, a woods- and cross-country-specific version of Yamaha’s potent thumper. This 449cc DOHC single deviates from the current YZ450F motocrosser in several key ways. First is engine tuning: Engineers lowered the compression ratio slightly and evolved the 44mm throttle-body EFI to civilize the MX motor’s ferocious hit for improved tractability, an essential skill for varied, slippery conditions. The five-speed gearbox ratios are also wider and the clutch beefier.
Various mods to the running gear further help the YZ450FX adapt to life in the wild woods. For instance, the KYB suspension (including the trick speed-sensitive fork) is tuned for cross-country work, and the seat is a half-inch lower. Additionally, an O-ring chain better repels grit (though it’s less efficient than a non-O-ring chain). A sidestand and skid plate are included, and the cross-country-spec Dunlop AT81 tires are ready for clay, loam, mud, sand, or rocks.
Likes: Priced $200 below the YZ450F; includes fuel-level and engine-warning indicators
Dislikes: Weighs a burly 262 pounds; skid plate is molded plastic…hmm
Verdict: A big, powerful, and fast woods racebike
