Yamaha has unveiled its all-new 2018 YZ450F, which features some pretty tasty upgrades and a whole new technology in the form of Wi-Fi engine tuning and shareable data acquisition, but we want to make sure to give some love to the rest of the 2018 Yamaha motocross model lineup, which returns mostly unchanged.
2018 Yamaha YZ250F, $7699
The YZ250F retains all of the features that have made it a top contender in the class for the past three years. Its manual kickstart, liquid-cooled, DOHC four-valve, fuel-injected engine, with its forward-positioned downdraft intake, is still a force to be reckoned with in the 250cc class, and its design concentrates the 250F’s key components—engine, fuel tank and exhaust system—toward the center of the motorcycle to centralize the overall mass as effectively as possible. The YZ’s bilateral beam aluminum frame features compact overall dimensions and is engineered for strength and rigidity while retaining optimal flex for comfort during long motos. Suspension chores are handled by KYB’s Speed Sensitive System spring-type up front and a fully adjustable KYB shock mated to a rising rate linkage system out back.
The YZ250F does not yet receive the Wi-Fi tuning system found on the new YZ450F, but its engine mapping can easily be retuned to suit track conditions via the use of Yamaha’s accessory GYTR Power Tuner, which lets owners adjust air/fuel mixture and ignition timing maps as well as monitor engine diagnostic codes.
2018 Yamaha YZ250, $7399
Two-Stroke power is the name of the game with the YZ250, which packs a 249cc liquid-cooled reed-valve-inducted two-stroke engine with a wide, hard-hitting
powerband into a quick-handling, backbone-style aluminum chassis. The patanted Yamaha Power Valve System (YPVS) is designed to give riders the best of all worlds–crisp, hard-hitting bottom-end acceleration with strong midrange and a potent top-end charge. Carburetion is via a 38mm Keihin PWK carburetor with a power jet and throttle position to provide precise fuel/air mixing and crisp throttle response. Other engine features include an intake with special-design carbon fiber reed-valve petals to improve throttle response and engine performance across throughout the rev range. The YZ250 engine metes power through a heavy-duty, multiplate clutch to a close-ratio five-speed transmission.
The 250’s KYB 48mm forks feature the Speed-Sensitive System that uses piston speed to control damping force for better bump absorption and better handling. Out back, a fully adjustable KYB® shock features reduced-friction Kashima Coat™ internals, 12.4 inches of travel, separate adjusters for high- and lowspeed
compression damping, and a full lock oil rebound system.
2018 Yamaha YZ125, $6499
The 2018 Yamaha YZ125 boasts many of the same features of its YZ250 sister into a 125cc class package. Its compact 124cc reed-valve-inducted two-stroke helps produce an awesome power-to-weight ratio, and its race-developed intake, complete with reed-valve spacer is designed to improve acceleration throughout the powerband. The YPVS is also used to deliver quick throttle response and a wide powerband for a 125cc class contender. The YZ125 features a close-ratio six-speed transmission.
Like the YZ250, the YZ125’s aluminum frame features a removable aluminum rear subframe constructed of square-section tubing for reduced weight. Suspension chores are tackled by a KYB Sensitive System 48mm fork up front and a fully adjustable KYB shock with reduced-friction Kashima Coat™ internals, 12.4 inches of travel, separate adjusters for high- and low-speed compression damping, and a full lock oil rebound system. Other features include an aluminum handlebar, two-position adjustable handlebar clamp, wide footpegs, a gripper seat and adjustable clutch lever with works-style
2018 Yamaha YZ85, $4699
Always a contender in the 85cc mini class, the 2018 Yamaha YZ85 boasts aggressive, modern styling, adjustable controls to accommodate a wider range of kid sizes. Its compact, liquid-cooled, 85cc crankcase reed-valve-inducted two-stroke engine is designed to deliver hard-hitting power throughout the rpm range. a close-ratio six-speed transmission and heavy duty multiplate clutch are claimed to offer smooth, precise gear changes and maximum hookup for outstanding
acceleration and corner-exiting power. The YZ85 also features an ultra-rigid, single-backbone, semi-double-cradle frame that places an emphasis on razor-sharp handling, and its fully adjustable suspension offers a broad adjustment range to suit any rider from novice to expert.
For more information on all 2018 Yamaha YZ models, visit https://www.yamahamotorsports.com/