• Revamped carburetor settings deliver crisper, more linear throttle response for optimal engine output.
• Remapped digital CD ignition system delivers more precise spark and optimal timing for faster, stronger response during hard acceleration, and less kickback during starting.
• All-new hydroformed swingarm is lighter and stronger for reduced weight, greater rigidity and more compliant rear suspension action, while an anodized finish gives it a trick, factory team-style look.
• Rear shock refinements include improved actuation, a new linking ratio and enhanced damping force.
• Revamped front fork settings deliver improved damping force with less bottoming for a smoother, more compliant overall stroke.
• Lightweight front wheel hub reduces unsprung weight and increases durability.
• Larger rear brake disc means greater stopping power.
• Reworked handlebar mounts are increased in size to help accommodate a wider range of riders.

• Liquid-cooled, 249cc, 5-valve, DOHC, 4-stroke is the world's most powerful, quarter-liter 4-stroke motocrosser with a stratospherically high, 13,500-rpm redline.
• Titanium valves and load-reduced springs decrease weight by more than 40% and reduce reciprocating mass for faster-revving, harder-hitting power delivery across the rev range.
• Trick, works-style clutch lever features race-spec barrel adjuster for on-the-fly adjustability.
• Slick-shifting, 5-speed transmission with heavy-duty, multi-plate clutch features an involute spline setup, ensuring smoother shifting and instant hookup under power, as well as reduced horsepower loss.
• 37mm Keihin FCR flat-slide carburetor with throttle position sensor (TPS) ensures ultra-precise fuel/air mixing and lightning-quick throttle response.
• Digital CD ignition system delivers more precise spark and monitors engine speed to ensure optimal timing for faster, stronger response during hard acceleration.
• Large-capacity radiator provides outstanding cooling efficiency.
• Lightweight exhaust system with specially shaped header angle maximizes engine power and allows hassle-free replacement of oil filter.
• Aluminum exhaust silencer looks trick and reduces weight.
• Primary kickstarting with integrated hot-start button ensures easy restarts in any gear.
• Dry sump lubrication system uses frame as oil tank, helping to create a more compact engine and chassis for superb handling performance.
• Magnesium cylinder head cover helps shave weight.

• Ultra-rigid, high-tension steel, YZ 125-style twin-spar frame is super-lightweight and strong for minimal flex.
• Lightweight 46mm inverted Kayaba cartridge fork features 11.8" of travel with compression and rebound adjustability.
• Low-friction outer tubes and aluminum piston rods ensure smoother, more compliant fork stroke for superior handling and lighter steering.
• Removable aluminum rear subframe reduces weight and allows easy maintenance.
• Rear suspension system features fully adjustable Kayaba shock with 12.4" of travel and separate adjusters for high- and bow-speed compression damping.
• YZ-426F-spec brake system features all-new 250mm fully floating front disc and 245mm rear disc brakes.
• Lightweight 21" front and 19" rear rims provide exceptional durability and help reduce unsprung weight for optimal suspension performance.
• Premium Dunlop 739 knobbies offer competition-spec traction and excellent wear.
• Specially designed steering crown, seat, fuel tank, handlebar, footpegs and radiator shrouds create ergonomically balanced riding position that permits easy rider movement and greater weight transfer flexibility during aggressive riding.
• Team Yamaha-inspired two-tone (black/blue) seat.
• Wide, cleated, folding cast alloy footpegs provide excellent comfort, grip and ground clearance.
• Cleated rear brake lever and folding shift lever tip offer superb grip and excellent durability.
• Repackable exhaust silencer.
• Durable, comfortable handlebar grips.
• Stainless steel clutch cable for longer life.

Specifications: