The 4-titanium-valve cylinder head is matched to a newly recalibrated fuel injection system to provide superb power feeling across the rpm range. The adjustable fuel injection system uses a 44mm throttle body fed by a high pressure battery-less electric pump to ensure optimum fuel atomization and air/fuel calibration for excellent readability in a wide range of riding conditions. The YZ450F instantly adapts to changing air/fuel mixtures depending on altitude and temperature, for an engine that delivers no matter what conditions.

The new aluminum Bilateral Beam frame offers a superb rigidity balance and, with new settings to already class leading front and rear suspension, provides unmatched lightweight handling and cornering. For 2014, the steering head pipe is moved 10mm closer to the rider, making for a more compact chassis dimension and placing more weight bias on the front wheel which translates to an even more precise and instinctive handling character.

Accessory GYTR® Power Tuner lets owners adjust air/fuel mixture and ignition timing maps to match engine performance characteristics to the rider and track conditions in a matter of seconds with the push of a few buttons.

Engine Features

For 2014, the top end - piston, intake, and exhaust valves and ports, valve mechanism, ignition timing, and fuel injection mapping - have all been meticulously revised, resulting in improved combustion and outstanding engine performance throughout the power band, with a focus on controllability.

The new high-performance ECU provides great bottom end torque plus delivers a strong feeling of power from 3rd gear up while new gear ratios also lengthen the powerband and heighten the feeling of power in 2nd and 3rd gear.

The valve mechanisms and cylinder head feature new specs that take performance to the next level. Intake and exhaust valves are enlarged and the cam profile for the intake has been modified, all contributing to improved combustion, resulting in added power and outstanding performance.

The exhaust pipe has an innovative layout, circling the cylinder, giving the exhaust pipe proper length for an excellent exhaust pulse effect. At the same time, the exhaust pipe has three different diameters throughout the exhaust tract, bringing out excellent power characteristics. This new layout allows the silencer to be positioned 186mm further forward behind the side panel closer to the middle of the bike which centralizes the mass for superior handling.

The compact wet sump lubrication system with piston cooler spray jet eliminates the need for an oil tank, reducing engine weight. The water pump employs a plastic resin impeller for further weight reduction. The reduced size of the crankcase enabled by this lubrication system design is a major factor in making it possible to mount the 450cc engine on the newly designed compact frame to deliver precise and instinctive handling.

Newly designed transmission and shift mechanisms provide quicker, smoother shifting under power with less effort.

The accessory GYTR Power Tuner can simplify the work of adjusting fuel injection volume and ignition timing settings to fit personal preferences or track conditions.

Chassis/Suspension Features

A newly designed aluminum Bilateral Beam frame is adopted in which the head pipe is moved 10mm closer to the rider. The overall dimensions are roughly the same as the frame of the 2013 YZ250F. This gives the YZ450F a new compact chassis that provides the most instinctive handling in the 450 motocross class.

The aluminum muffler is positioned closer to the machine’s center of gravity as it is almost completely hidden by the side number plate. The layout allows a shorter, lighter sub frame and also contributes to mass centralization for lightweight handling feel.

The front suspension has proven KYB® air-oil separated forks. It adopts new spec inner and outer tubes coupled with optimized suspension settings. The new rear suspension also features a new reservoir location and spring spec with settings optimized for ideal damping characteristics to match the new chassis dimensions.

The new larger diameter 22mm front axle and new top triple clamp increase rigidity for improved handling and front end feel. The handlebar mounts are now rubber mounted to improve comfort and reduce handlebar vibration.

A new layout for the fuel tank and air cleaner box gives the machine a slimmer feeling between the legs as well as positions fuel tank mass closer to the center of the bike which improves handling feel. Furthermore, the air box can now be accessed without removing the fuel tank for easy serviceability of the new larger air cleaner element.

A new narrower radiator design contributes to slimming down the radiator panel area.

Additional Features

“In-mold graphics” technology is a method in which the graphics are molded into the radiator shrouds for improved decal durability and reduced scratches.

Riders have a choice of two color options: Team Yamaha Blue/ White or White/Red.