Yamaha has revealed details of their much-updated WR250F for 2020. There’s a lot of new in the brew as the 2020 model is development of the latest YZ-F motocrosser. So it’s a new chassis and engine, both much like before in general engineering terms, but in the detail there’s a lot of change. If it’s anything like the update that Yamaha made to their excellent 2019 WR450F (read about that in RUST #42 here) then we can expect considerable dynamic changes. So here’s a quick review of what’s coming:
New engine, based on the latest YZ-F, now with a higher compression ratio of 13.8:1, ‘optimised’ exhaust cam timing and new intake port valve seats to boost low-to-mid torque.
New Denso 12-hole injector (was 10-hole) with new 44mm throttle body (by Mikuni) and revised intake funnel.
New crankshaft balancer weight.
Lighter starter motor.
Lighter, tougher clutch.
Compatibility with the Power Tuner smartphone app.
Handlebar-mounted engine map switch.
Yamaha say the new motor ‘delivers stronger power throughout the rev range together with increased performance at higher rpm’.
Latest bilateral beam frame with straight fuel tank rails and new engine mounts. Now with 15% more overall chassis rigidity.
Latest KYB AOS (Air Oil Separate) forks.
New KYB rear shock, now 350gms lighter with 30cc more reservoir capacity.
Larger 7.9-litre fuel tank (+0.5-litres)
New headlight cowl.
The 2020 WR250F (&2020 WR450F) will be in dealers from October 2019. Note for Europe these will be competition models, without EU4 homologation.