YZ250F
This is the bike that has totally revolutionised the 250 class. And dominated on racetracks around the globe. With its radical reverse cylinder head, rearward sloping cylinder and underseat fuel tank, the YZ250F is the way ahead for motocross design.
Now to underline Yamaha’s policy of continuous development, we’ve made a range of technical improvements designed to keep the YZ250F on top. This high-tech motocross bike comes with an all-new high-performance reverse cylinder head that gives you the winning advantage. And with its re?ned aluminium frame and new suspension settings, you can run harder and faster from the gate to the ?ag.
So whether you’re an experienced pro racer or a hard-charging amateur, the revolutionary YZ250F delivers all the power and agility that you need to maximise your potential.
250cc liquid-cooled DOHC 4-valve engine
With its front facing inlet and rear exiting exhaust, the YZ250F's innovative reverse cylinder head offers many advantages over a conventional design. These include increased intake and exhaust efficiency, as well as enhanced mass centralisation thanks to the use of a top-mounted air filter and underseat fuel tank. Yamaha's engineers have taken this cutting-edge technology to the next level, and developed a new reverse cylinder head that gives the YZ250F rider even stronger mid to high rpm pulling power.
Aluminium bilateral beam frame
Using feedback from our factory teams, Yamaha has been able to fine-tune the frame in order to ensure that YZ250F riders are able to fully exploit the increased engine performance of the uprated model. Compared to the 2016 design, the 2017 frame is around 12mm wider in the area behind the swingarm pivot point, and this increased torsional rigidity ensures a higher degree of handling stability.
Air-Oil-Separate upside-down forks
Increased rideability and comfort have been achieved on the 2017 YZ250F through a number of revisions to the front and rear suspension. The class-leading Air Oil Separate (AOS) KYB® front forks feature a new more rigid outer tube design and slightly reduced oil capacity, and these changes - together with new factory suspension settings - give improved rider feedback for improved chassis performance and stability in ruts, bumps and corners.
Improved ergonomics
To achieve a roomier riding position that best suits a wide range of racers, the footrest position on the 2017 YZ250F has been lowered by 5mm. This also helps to lower the centre of gravity to give increased control in ruts and corners.
Improved stopping power
For improved brake feel, the 245mm rear disc is manufactured using the same heat resistant steel as the 270mm front disc, giving total braking confidence on the fastest tracks.
Easy access airbox
Quick release fastners on the airbox allows for easy access, to the large capacity air filter.
Mass centralisation
The muffler is moved forward. The exhaust pipe, which needs a certain length for good low and mid range torque, winds around the cylinder head like a snake, centralising weight.
Optional Power tuner
Riders of all abilities can use the optional Yamaha Power Tuner to adjust the YZ250F's power characteristics. This compact device plugs straight into the bike without the need for a PC, and enables the rider or mechanic to fine-tune the engine performance in seconds to suit the track conditions.
Engine
| Engine Type | Liquid cooled, 4-stroke, DOHC, 4-valve |
|---|---|
| Displacement (cc) | 250.0 |
| Bore x Stroke (mm) | 77.0 x 53.6 |
| Compression Ratio | 13.5 : 1 |
| Lubrication System | Wet sump |
| Fuel Management | Fuel Injection |
| Ignition | TCI |
| Starter System | Kick |
| Fuel Tank Capacity (L) | 7.5 |
| Final Transmission | Chain |
| Transmission | Constant mesh 5-speed |
Chassis
| Frame Type | Bilateral beam |
|---|---|
| Suspension Front | Telescopic forks, 310mm travel |
| Suspension Rear | Swingarm (link suspension), 315mm travel |
| Brakes Front | Hydraulic single disc, 270mm |
| Brakes Rear | Hydraulic single disc, 245mm |
| Tyres Front | 80/100-21 MS32 Tube type |
| Tyres Rear | 100/90-19 MS32 Tube type |
Dimensions
| Length (mm) | 2170 |
|---|---|
| Width (mm) | 825 |
| Height (mm) | 1280 |
| Seat Height (mm) | 965 |
| Wheelbase (mm) | 1475 |
| Ground Clearance (mm) | 330 |
| Wet Weight (kg) | 105 |
