2011 Yamaha YZ450F

An award-winning bike that offers no compromises; that’s what the Yamaha YZ450F offers - and a whole lot more.

Fresh off of improvements across the board, the new YZ450F will come with a host of beefy upgrades, including new design elements, improved powertrain, and overall better handling.

These changes fit right in with the lofty standards set by the models predecessor, the 2010 YZ450F , which won a plethora of awards including Dirt Rider Magazine’s “Bike of the Year”, Cycle World’s “Best Motocrosser”, and Motorcycle Magazine’s “Best Dirtbike of 2010.”

Yet despite all of its accolades, Yamaha still saw fit to give the YZ450F improvements, further proving that a great bike should not be satisfied with itself. Whenever there’s a time that awards come, they should not be looked as validation for greatness, but motivation to maintain their status as the best.

For their part, Yamaha has the right frame of mind with the YZ450F. It’s a good enough bike to merit some distinctions, but at the end of the day, ’good enough’ should never be associated with status quo.

Find out more about the Yamaha YZ450F after the jump.

Design

Yamaha YZ450F

The design of the Yamaha YZ450F offers a fresh look at the talent of Yamaha designers in building a model that comes with a minimalistic design that swaps traditional intake and exhaust positions, putting the lightweight airbox and throttle body out front. This allows the bike to offer better handling while also achieving combustion efficiency and in the end, contributing to the bike’s mass centralization.

The revamped looks of the new YZ450F also deliver next-generation styling, including front and rear fenders, intake cover, front fork protector, and number plate, along with the fuel tank and seat. An Accessory GYTR Power Tuner allows bike tuners to adjust air/fuel mixture and ignition timing maps to match engine performance characteristics to the rider and track conditions.

Performance

Yamaha YZ450F

Powering the Yamaha YZ450F is a rearward-slanted engine that enabled engineers to design straight intake and exhaust ports, creating the most direct path for air flow into the fuel-injected engine for incredible performance. The bike also uses a battery-less fuel injection system with a 12-hole injector for superb fuel atomization and a 44mm Keihin throttle body that was designed for easy starting, with an integrated cold start and idle speed adjustment knob. Yamaha FI provides optimal air/fuel mixtures in all altitudes and wide range of temperatures for outstanding throttle response. A 4-titanium valve cylinder head with a “pent-roof” design combustion chamber provides excellent combustion efficiency and unequaled power output while an intake and exhaust camshaft profile changes to increase valve working angle and valve lift for most excellent performance at all rpm. There’s also an air filter chase, which has been changed to accommodate the bike’s engine layout and a “Tornado-style” exhaust header with a resonator that efficiently scavenges exhaust gasses and helps the engine achieve its exceptional low-to-mid range torque characteristics, while the 150mm-longer muffler comfortably meets the latest noise standards without a sacrifice of power.

Chassis and Suspension

Yamaha YZ450F

An aluminum Bilateral Beam frame is crafted from a carefully chosen combination of forged and extruded aluminum, 16 components in all, for the right rigidity balance and light weight. The YZ450F has a very symmetrical chassis design promotes nimble handling while a redesigned swingarm and rear shock are optimizes and delivers exceptionally linear performance for excellent bump absorption and awesome cornering ability. A KYB Speed Sensitive front fork has excellent feel and
shock absorption while a KYB rear shock with large capacity piggy back reservoir and 50mm piston offers more consistent damping control. The front and rear fenders, along with the number plate, side cover and front fork protector have been designed for an aggressive look.

Specifications

Yamaha YZ450F
ModelYZ450FAL; YZ450FAB
Engine Type449cc liquid-cooled DOHC 4-stroke;
4 titanium valves
Bore x Stroke97.0 x 60.8mm
Compression Ratio12.5:1
Fuel DeliveryYamaha Fuel Injection (YFI), Keihin® 44mm
IgnitionCDI
TransmissionConstant-mesh 5-speed;
multiplate wet clutch
Suspension/FrontKYB® Speed-Sensitive System, inverted
fork: fully adjustable, 12.2-in travel
Suspension/RearKYB® Fully adjustable single shock;
12.4-in travel
Brake/FrontHydraulic single disc brake, 250mm
Brake/RearHydraulic single disc brake, 245mm
Tire/Front80/100-21-Dunlop® D-742FA
Tire/Rear120/80-19-Dunlop® D-756
L x W x H86.3 x 32.4 x 51.6 in
Seat Height39.3 in
Wheelbase58.7 in
Ground Clearance15.0 in
Fuel Capacity1.63 gal
Wet Weight245 lb
ColorTeam Yamaha Blue/White;
White/Red

Quote

Motorcycle.com Says " This good Motorcross" It’s officially another year (well, according to the manufacturers, anyways) and Yamaha has introduced another competitive motocross machine: The 2011 YZ450F. Although very similar to last year’s revolutionary 2010, this bike has undergone a couple of revisions. The first is the YZ450F’s fuel tank, which has an increased capacity of 200ccs from 6.0 to 6.2 liters. The clutch arm ratio has also been changed to decrease lever free play during long motos. The arm length has been increased by 6mm, moving it from 35mm to 41mm, and the cam shape has an increase of 0.6mm, taking it from 3.9mm to 4.5mm. Aside from performance changes, the new YZ-F has been given white lower side shrouds similar to the YZ250F.

OTHER BIKES, PLEASE MOVE TO THE REAR

The revolutionary YZ450F will have many gazing far into the future. By slanting the cylinder rearward and reversing the intake and exhaust ports, the YZ450F’s mass is more centralized for amazing balance, unprecedented handling and cornering. The bilateral beam frame and suspension offer fantastic feedback to the rider. Add fuel injection to the mix of these innovations and you’ll agree: backward is the right way forward.


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