How do you improve on an enduro bike which can appeal to new riders and top racers? By evolving the 2020 Yamaha WR250F to be quicker, stronger and lighter than the current model.
The engine of the 2020 Yamaha WR250F is closely based on the one used in their competitive YZ250F motocross machine. It features a new forged aluminium position for a higher compression ratio of 13.8:1. Working with the new exhaust cam timing and intake post valve seats, you get more low-to-mid torque, which is great for tackling obstacles and tricky terrain.
It also gets a new 12-hole injector, a 44mm Mikuni trottle body and a revised intake funnel for stronger power, with a new crankshaft balancer weight to keep everything manageable throughout the rev range. Plus lower cylinder cut-outs to reduce pumping losses, a relocated oil filler, an almunium impeller and re-rerouted water pipe, a new double electrode spark plug and even lightweight bolts and screws.
But if the power delivery isn’t quite right, you can use the handlebar-mounted dual engine map switch to swap between factory-set modes. Or even tune and create your own via the Power Tuner smartphone app. So instead of fiddling with engines, you can choose 3 factory mappings, or from 16 adjustable values for fuel injection and ignition timing on your phone (including a 3D map of the values).
You can also share your set-ups with friends, along with checking out engine diagnostics, a race log and more via the app.
If you do take a break, the lightweight and compact 50mm diameter, 390W starter motor should be quick and easy to use. And a lighter but tougher clutch should handle heavy abuse due to special heat resistance frcition plates with a knurled finish, matched to the 6-speed wide-ratio gearbox.
But the improvements for the 2020 Yamaha WR250F aren’t just about power. Everything is housed in a new alluminium bilateral beam frame with straight fuel tank rails and new engine mounts to increase overall rigidity by 15%.
At the front are YZ250F-type Ail Oil Seperate Kayaba front forks with 25mm diameter tubes, with a new leaf spring in the mid-speed valve to help with low speed damping. And there’s a stronger and 350 gram lighter rear coil spring, plus a 30cc larger reservoir for the shock.
The chassis also carries a larger 7.9 litre slimline fuel tank, with the extra space coming underneath to maintain the best balance and centre of gravity, plus slimmer bodywork including new radiator shrounds, sidepanels, rear mudguard and airbox cover.
You also get a sleeker new headlight cowl lower on the forks and closer to your riding position, and a new lightweight plastic resign skidplate which will help prevent damage and dirt, but will glide over rocks and trees without getting stuck. Despite the larger tank, the result is a narrower bike, which also has a lower, flatter seat.
The 2020 Yamaha WR250F will be available in dealers from October 2019, alongside the bigger, similarly redesigned WR450F. It’s sold in race specifcation without EU4 homologation, so isn’t road legal. Which means you need to keep it on closed tracks, private areas and for events which allow non-registered bikes, and no taking it on the public highways otherwise.
Obviously if you want to take things further, there’s a whole range of accessories and parts available to make your 2020 Yamaha WR250F closer to a factory-style bike from titanium exhausts and billet clutch covers to wheels, protectors and more.
2020 WR250F Key Features
- All-new design for 2020
- 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
- 6-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 2-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
The Yamaha WR250F was first introduced in 2001, sharing elements including the engine (slightly de-tuned) with the same model year YZ250F. The WR in the name refers to the wide ratio gearbox. As a result of the 18-year history, you can find a lot of examples for sale secondhand on sites including eBay if you’re tempted by some enduro riding.
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