Yamaha announce healthy model update for the 2020 WR250F – a “quicker, stronger and lighter enduro bike”.
Yamaha has released technical details of the new, 2020 WR250F enduro bike ready to stand alongside the already heavily revised WR450F and set for dealer availability in October 2019.
As is the trend with Yamaha in recent years, the new WR250F is heavily based on the existing YZ motocross model. Featuring a new version of the reverse-head engine together with the very latest bilateral aluminium beam frame, 7.9 litre tank, Power Tuner App friendly ECU, higher performing engine and slimmer bodywork, Yamaha claim the new-generation WR250F is the most advanced 250cc four stroke enduro bike they have ever built.
2020 WR250F in a nutshell:
- New YZ250F-based high-performance enduro-spec engine
- Revised exhaust cam timing and reshaped exhaust ports
- New Denso 12-hole fuel injector with new 44mm Mikuni throttle body
- New multi-angle intake port valve seats
- Higher compression lightweight piston
- New crankshaft balancer weight
- New heavy-duty heat-resistant clutch
- New lightweight and compact electric starter motor
- New high-output ACM
- Six-speed wide-ratio transmission with revised shift cam
- Enduro-specific fuel injection and ignition timing mapping
- Compatible with Yamaha's free Power Tuner smartphone app
- CCU enables Power Tuner app
- Handlebar mounted two-mode mapping switch
- Newly-developed bilateral beam frame with enduro-specific engine mounts
- New YZ250F-type AOS front forks with larger 25mm inner cylinders
- New lightweight rear shock
- Larger capacity 7.9 litre fuel tank
- New resin engine guard
- New YZ250F-type front axle brackets
- New flatter and lower YZ250F-type seat
- Tough new wear-resistant in-mould graphics
That was the short version, here’s what Yamaha have to say in detail about the WR250F, now in its 20th year keeping riders happy competing in the E1 class just as it is popular with trail riders…
High-performance YZ250F-based engine
The YZ250F has a high level of competition to its name in the hands of Monster Energy Kemea Yamaha riders Jago Geerts and Ben Watson in the 2019 FIM MX2 World Championship, as well as Dylan Ferrandis in the 2019 AMA 250 Supercross and Motocross Championships in the USA. Notable by its absense of course is a team competing in EnduroGPs.
The 2020 WR250F engine is closely based on the latest YZ250F design, and features performance-boosting technology that gives stronger, linear power throughout a wide operating range. A new forged aluminium piston achieves a higher compression ratio of 13.8:1 and, together with new exhaust cam timing and intake port valve seats, boost low to mid-rpm torque levels.
Sharper power delivery with more throttle feel
The previous model's 10-hole injector is replaced with a new 12-hole injector plus a new 44mm Mikuni throttle body and a revised intake funnel. To match these changes and improve the power feeling the 2020 WR250F has a new crankshaft balancer weight.
Compared to the previous engine, Yamaha says the 2020 WR250F has stronger power throughout the entire rev-range and increased performance at higher rpm making it, again, their strongest ever 250cc, four stroke enduro engine.
Lighter starter motor
For easy starting and faster restarts during a race, the new model is fitted with a lightweight and compact (50mm in diameter) starter motor. Located close to the centre of the chassis the 390W starter motor is powered by a compact lead-type battery, and a new ACM provides a strong and reliable electricity supply.
Lighter and tougher clutch
Enduro is a tough environment for any motorcycle clutch and the 2020 WR250F's six-speed, wide-ratio transmission features a newly designed, lighter and tougher clutch. Heat resistant friction plates with a “knurled finish” help give a light feel at the lever and which Yamaha says is designed to perform consistently and effectively for long periods in the toughest terrain.
Enduro-specific free flow air filter
Yamaha's unique reverse head engine features a front facing air inlet with the airbox mounted in front of the fuel tank. For 2020 a newly designed and enduro-specific air filter is fitted, enabling tool-free filter changes.
The length of the inlet combined with the free-flow design of the filter contribute towards the new engine's feeling for traction and linear power delivery, and its welded construction and additional rubber seals around the positioning pin ensure that only clean air reaches the combustion chamber.
Compatible with the Power Tuner smartphone app
For 2020 the WR250F's power characteristics can be wirelessly tuned using a smartphone loaded and Yamaha’s Power Tuner app. Previously this was only possible with the Yamaha Power Tuner device.
The Power Tuner app enables a greater range of settings, giving the opportunity to adapt the power output according to preference, terrain and riding conditions. Riders have the choice of three available factory mappings and the possibility to select from 16 adjustable values for fuel injection and ignition timing, giving a wide range of potential settings.
The Power Tuner app also features a race log, engine diagnostics, real-time monitoring screen and data back-up function, and the app allows riders to share and compare maps and race logs to help get the most from the bike.
Engine map switch
The WR250F is equipped with a handlebar-mounted dual engine map switch as previously. This features two factory-set modes, but riders can choose also to use their own custom maps with the Power Tuner app. These can be uploaded to the WR250F's CCU (Communication Control Unit), and the rider can switch between each map to suit changing conditions while riding.
Other engine changes for 2020:
- Revised lower cylinder cut-outs reduce pumping losses
- Relocated oil filler and oil level gauge
- Aluminium impeller and re-routed water pipe
- New double electrode spark plug
- Lightweight bolts and screws
New 2020 YZ250F chassis
The new aluminium bilateral beam frame features a revised layout including straight fuel tank rails, and in order to achieve the desired balance of rigidity it is fitted with newly developed main engine mounts with additional external plates.
The new design achieves around 15% increase in overall chassis rigidity for claimed improved feel and feedback.
Industry leading KYB front and rear suspension
Yamaha's front and rear suspension systems are widely regarded as being amongst the best OE in the off road world. For 2020 the WR250F is fitted with YZ250F type AOS (Air Oil Separate) front forks that use enduro-specific settings for low and high-speed riding situations on a wide range of surfaces.
Running with 25mm diameter tubes – 1mm more than the previous model – the new Kayaba (KYB) forks have increased oil flow rate for improved feel. A new leaf spring in the mid speed valve (MSV) responds to the smallest amount of oil flow to give improved low-speed damping.
Yamaha says the changes give a more controlled feeling with smooth transitional performance between the compression and rebound strokes. The new forks also feature higher rigidity front axle brackets from the MX model that help eliminate flex for an increased feeling of traction, stability and manoeuvrability.
At the rear the new YZ250F-derived shock absorber is fitted with a stronger and lighter coil spring with a 350 gram weight saving, and for cooler and more stable damping characteristics the reservoir capacity is increased by 30cc.
Larger capacity slimline fuel tank
The new WR250F delivers has improved its riding range thanks to a larger 7.9 litre fuel tank, an increase of 0.5 litres over the previous model. The new design has been developed from the YZ250F, and the additional capacity has been achieved by extending the tank downwards towards the bike's centre which also improves balance, Yamaha claims.
Slimmer and sharper bodywork, improved ergonomics
Bold, new race-bred looks bring the 250 in-line with the new-for-2019 WR450F and the latest YZF motocross models. The new radiator shrouds and airbox cover give a smoother and more unified appearance, while the new side panels and rear fender give a more aggressive look manufactured in tough, new wear-resistant in-mould graphics.
The 2020 bodywork is actually slimmer than the previous design despite the larger fuel tank and, together with a flatter and lower seat, the ergonomics and rider mobility are improved.
Sleek new headlight cowl
The WRF family look is strengthened with the use of a sleek new headlight cowl that sits lower on the forks and is positioned closer to the rider. Not only does this contribute towards mass centralisation, it also creates a light and agile feel from the rider's viewpoint.
Tougher, lightweight skid plate
The WR250F runs a new, plastic resin skid plate to shield the frame, water pump, hoses and engine cases. It also prevents dirt and mud ingress that can increase running weight.
Lightweight speed sensor and high-precision display
A new, lightweight front wheel sensor sends data to a high-precision speed digital display, eliminating the previous model's speedo drive cable and collar and helping faster front wheel removal and installation. The compact display also includes fuel level and engine management indicators.
The 2020 WR250F, as well as the 2020 WR450F, will be available at Yamaha dealers starting in October 2019 and will be only available in race specification for closed circuit use in many parts of the world depending on vehicle licensing in your country.
Genuine Yamaha Accessories
Genuine Yamaha Accessories and GYTR® Performance Products as ever enable riders to transform their stock Yamaha into a unique factory-style race bike and includes titanium exhausts, slip-on mufflers, billet clutch covers, discs, wheels, protectors and more.
More information and pricing in your part of the world visit: Yamaha-Motor.com
Jon PearsonEnduro21 Editor and Bike Testerjon.email@example.com