Using feedback from our factory teams, Yamaha has been able to fine-tune the frame in order to ensure that WR250F riders are able to fully exploit the increased engine performance of the uprated model. The new 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.
On board WiFi means that you can tune the new WR250F to different track conditions using your smartphone. A downloadable Power Tuner app allows you to make fuelling and ignition timing changes instantly and upload/share them for the ultimate in track-side tuning. The free Yamaha Power Tuner app also allows owners to record ride/race log information and monitor a range of data such as maintenance and system diagnosis, engine run time and more.
A new lightweight front wheel speed sensor connects to a highly precise speed display and with no more speedo drive, makes front wheel changes easier. The system features a pulse wheel and sensor system known for excellent reliability and provides the detailed speed information essential for enduro riding. Display includes low fuel warning light.
A lighter and less obtrusive forged aluminium sidestand is positioned to ensure plenty of ground clearance when riding through ruts and the like. The new stand sits higher and the amount it juts out from the chassis is reduced which helps prevent snagging. The weight of the stand has also been reduced by about 100g. This is the same as the 2019 model YZ250FX stand design.
The WR250F's transmission is equipped with a newly developed clutch that has been specially developed to handle hour after hour of punishment. And to optimise the performance of the new fuel injected engine, there's a purpose-built wide ratio 6-speed transmission.
The filter element features reduced airflow resistance and intake noise combined with increased reliability. The new filter and the length of the intake funnel contribute to an excellent feeling of traction and linear characteristics during acceleration and deceleration. Plus, dust filtering capability is increased by adding rubber seals to the centre positioning pin.
Riders of all abilities can also use the optional Yamaha Power Tuner to adjust the WR250F’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.
The new WR250F engine features a new high compression forged aluminium piston, revised valve angle and exhaust cam timing with revised balance factor - all based closely on the winning fuel-injected YZ250F design. Its airbox is situated in front of the rider and the fuel tank located at the centre of the bike – a unique configuration that contributes to the bike's mass centralisation, which plays a pivotal role in achieving light and agile handling.
WR250F runs the same KYB air-oil-separate closed chamber upside-down front fork as the YZ250F but with model-specific enduro settings to provide stable damping force. This suspension is acknowledged to be the best available on a production dirt bike and responds particularly well during the transition between the compression and rebound strokes. And because the suspension holds up well in the stroke, ground clearance is improved over the outgoing model.
The WR250F'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 offers even stronger mid to high rpm pulling power.
A bar-mounted dual engine map switch has been adopted and positioned next to the left lever to enable changes in the engine power delivery characteristics mid-race. This switch allows the rider to select one of two engine maps on the fly at the press of a button to cater for changes in the riding environment. This means that when the going gets loose, steep or muddy – high traction can be accessed at the press of a button.
Increased rideability and comfort have been achieved on the WR250F through a number of revisions to the front and rear suspension. The class-leading Air Oil Separate (AOS) KYB front forks feature slightly reduced oil capacity and new factory suspension settings to give improved rider feedback and improved stability in ruts, bumps and corners.
The mass centralised design is a concept we pioneered, and it's what gives the WR250F the edge over the competition. By locating major components like the fuel tank, cylinder and exhaust system close to the centre of the chassis, we've been able to create an enduro bike whose agile handling gives the Yamaha rider a real advantage - all day long.