New 2021 YZ250F aims for the podium!
For 2021, Yamaha's motocross focus is on the YZ250F. After the major innovation for the YZ450F, the blue MX2 machine adopts numerous improvements from its big brother. How competitive Yamaha is in this class is evident from the results worldwide. Dylan Ferrandis took his second West Coast SX title and Jago Geerts won the first MX2 GP of the season.
The new YZ250F: Tuning. To race. To win.
The YZ250F has already made a big name for itself as one of the most competitive 250cc four-strokes available. At every level, this excellent motocross bike has proven that it has what it takes to win in all conditions, both in MX and SX. For the 2021 model year, Yamaha is aiming even higher with the introduction of the new YZ250F into this ultra-competitive class, equipped with a thoroughly refined engine, revised frame, new suspension settings, new brakes and advanced digital technologies.
Completely redesigned engine
Every major component has been redesigned and improved to give Yamaha riders a real advantage on the track. With its class-leading inverted cylinder head, which improves intake efficiency and optimizes the center of gravity, the 250 cc four-valve engine is already in a class of its own.
For the 2021 model year, Yamaha engineers have analyzed all major components and made a host of significant changes designed to give a wider range of more powerful and smooth performance to help you win races. The transmission has also been improved for smoother shifting.
New exhaust camshaft profile
The 2021 engine's power feel has been refined and improved from mid-range to overspeed through the use of a new exhaust camshaft with a revised profile that reduces valve overlap. Together with optimized fuel injection settings, this new camshaft improves the YZ250F's engine character above the mid-range, delivering higher performance and better handling.
Completely new, highly efficient intake system
The YZ250F's front intake is a key feature that gives this lightweight four-stroke a very real advantage. The intake not only provides cool, fresh air flowing directly into the engine for better combustion efficiency and instant throttle response, but also allows the use of a unique rear-slant cylinder. This improves the center of gravity, which improves the motorcycle's smooth maneuverability and excellent handling characteristics.
The intake system of the 2021 model is completely new. The redesigned airbox eliminates the need for the intake funnel. The airbox has also been shortened by 20mm to allow for a smoother and more direct route for the incoming air. Another important change is the new air filter housing cover at the front of the seat. The 2021 cover features new ducting and increases intake air volume for even better high-rpm performance.
New powerful exhaust muffler
To complement the increased high-speed performance of the 2021 engine, a new, larger capacity muffler has been fitted. Just 70mm longer than the previous design, the new system is designed to provide smoother acceleration, especially at high revs, and delivers a deep and subdued exhaust note that emphasizes the torquey character of this 250cc four-stroke engine.
Stronger clutch housing and smooth-shifting transmission
To complement the improved performance of the new engine, the clutch housing has been redesigned. The clutch holder has thicker walls that are significantly stronger, which increases durability and ensures consistently strong performance throughout the race. The 33de, 44de in 5. de gears on both the input and output shafts have been redesigned to improve transmission performance. Select gears are bead blasted for more power to match the improved engine performance.
Refined double cradle frame takes handling to new heights
The YZ250F is already known for its ultra-nimble and smooth ride, and through constant evaluation and testing, Yamaha's designers have been able to refine the frame construction and take chassis performance to the next level.
The 2021 YZ250F features a new dual aluminum cradle frame, which while externally similar to the previous design, features a number of significant changes that complement the improved performance of the 2021 engine. They provide a noticeable improvement in both driving feeling and performance. By fine-tuning the frame's stiffness levels in key areas, Yamaha's designers have created a chassis that combines lightweight handling with a precise and confident feel. Other chassis components, such as the triple clamp, handlebar mount and front axle, have also been redesigned to match the new frame, all contributing to the 2021 model's increased competitiveness.
Redesigned front and rear suspension settings provide greater control
Yamaha's motocross models are widely known to have the best suspension packages in the industry. At the front, the KYB® upside-down fork with speed-sensitive damping provides excellent handling characteristics, while at the rear the KYB® shock absorber and Monocross suspension work together to provide optimal control with plenty of grip for the rear wheel.
To ensure it maintains its name as one of the very best motocross suspension systems 'straight from the factory', the package has been further refined for 2021. The settings on the KYB® front fork have been revised to provide more progressive damping throughout the stroke. This gives the rider a stronger feeling of contact with the track surface while providing better shock absorption that helps the rider save energy. At the rear, the KYB® shock absorber has revised settings that provide a more stable ride with a reduced tendency to roll.
These significant suspension improvements, combined with the refined rigidity balance of the double cradle frame, take the handling characteristics of the 2021 YZ250F to an even higher level. The new model is not only easier to handle, but also provides a more precise feel. This makes it easier for the rider to hold the chosen line to take corners faster. Front and rear wheel traction is also improved by these chassis changes, improving machine control. This offers a significant advantage over the competition.
Lighter and more powerful braking system
For 2021, braking performance has been improved and the weight of the braking system has been reduced. The redesigned front brake caliper is 30% stiffer than before and uses larger diameter pistons and newly designed brake pads. A new 270 mm front brake disc also increases the contact surface by 16% without increasing weight. The rear brake caliper design is also new. Together with a new 240 mm rear brake disc, this system offers the same braking power, while weighing 120 grams less.
The new braking system delivers improved braking performance and more feeling. It is a major contributor to the increased competitiveness and improved riding experience of the 2021 YZ250F.
Revised steering position
To achieve the optimal riding position for improved handling, the 2021 YZ250F's handlebars are mounted further forward, allowing the rider to load the front end and shift their body weight over the front wheel as and when necessary.
The handlebar features a new lighter triple clamp with new handlebar clamps, both with a revised stiffness balance to reduce strain on the rider's arms. The new chrome-molybdenum steel footpegs are also lighter, as is the new front axle, meaning the Yamaha YZ250F weighs just 106kg with a full 6,2 liter fuel tank and 0,95 liters of engine oil – just 3kg more than the YZ250 two-stroke.
Dynamic new Icon Blue bodywork with matching number plates
Yamaha Racing has made blue its own style and for an even more refined and dynamic look, the 2021 YZ250F features new Icon Blue bodywork with matching front and side number plates. Furthermore, the rims, cylinder head and other engine details are also in blue. This gives the 2021 model a more powerful and stylish appearance in which Yamaha's DNA is clearly reflected.
Yamaha Power Tuner
The industry-leading Power Tuner is an easy-to-use digital technology that allows YZ250F and YZ450F riders to fine-tune their motorcycle's engine power on the track using their smartphone. Riders and mechanics can easily download the free Power Tuner app for IOS or Android devices. They can then connect directly to the YZ250F to change fuel injection and ignition timing via the engine's CCU. In the Power Tuner app, riders can make their own settings and use the handlebar-mounted button to switch between two of the maps.
In addition to making changes to engine performance, the Power Tuner can also be used to record race log data and monitor a range of data including system diagnostics, runtime and maintenance. Furthermore, it is possible to compare race logs and settings and share them with other drivers.
New features of the YZ250F for 2021
· Redesigned high-performance motor with stronger power at high speeds
· Smoother throttle response with a longer overspeed feeling
· Optimized exhaust camshaft design with new profile and less overlap
· Ideal fuel injection settings provide improved power character
Completely redesigned intake system increases high-rpm performance
· Larger capacity muffler for seamless high-rpm acceleration
· Stronger clutch housing for better engine performance
· Redesigned gears with optimized performance and power
· Double cradle frame with new specifications and an ideal balance between strength and stiffness
· Revised front and rear suspension settings provide improved handling
· Lighter and more powerful front (Ø 270 mm) and rear brakes (Ø 240 mm)
· Lighter triple clamp and revised handlebar position
· Lighter footrests made of chrome-molybdenum steel
· Lighter front axle
· Icon Blue bodywork and matching blue front and side panels
· Liquid-cooled DOHC 4-valve engine with inverted cylinder head
· Engine configuration with central low center of gravity and backwards inclined cylinder
· High-efficiency forward-facing intake and rear exhaust
· Lightweight titanium valves for ultra-responsive performance
· Lightweight exhaust provides a strong pulse effect
· Robust clutch with excellent feel
· The special shape of the shift camshaft enables smooth and precise shifting
· The Power Tuner app for smartphones enables precise, fast and easy tuning on the track
· Switch for 2 ECU maps for adjusting the engine character while driving
– Electric starter with lightweight lithium-ion battery
· Industry-leading KYB® upside-down fork with speed-sensitive damping
· KYB® rear shock and Monocross rear suspension
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