Cycle News Staff | June 6, 2018
The 2019 Yamaha YZ250F gets a major overhaul. It features an all-new engine, frame and bodywork. Suspension has been refined, as well.
The 2019 Yamaha YZ250F in Team Yamaha Blue
Yamaha went in search of more midrange and top-end performance for the new YZ250F. As a result, they updated the cylinder head, piston, cam profiles, and revised the exhaust system.
To improve cornering feel and straight-line rigidity, the YZ’s bilateral beam frame has new main spars, engine mounts and engine-mounting position (to maximize mass centralization). The cylinder head also has a more upright stance.
Like the YZ450F, which was heavily updated last year, the 2019 Yamaha YZ250F gets electric starting and Yamaha’s Power Tuner app, a first for a production 250F motocrosser.
The YZ250F will again be available in two color options—Team Yamaha Blue, and White. Both will sell for $8199.
Here is what Yamaha has to say about its newest YZ250F:
2019 Yamaha YZ250F in White
Yamaha Motor Corporation, USA, today introduced the entirely redesigned 2019 YZ250F, complete with electric start and the world’s first smartphone engine tuning app featured for a production 250cc motocross bike. An all-new engine, new frame, new bodywork and more are also major focal points of the extensive model redesign.
2019 YZ250F Updates
The 2019 YZ250F utilizes an all-new engine design that features electric starting, a new cylinder head, piston, camshaft profile, cylinder geometry, larger diameter clutch and more. Working together, these changes produce more mid-range and top-end power and deliver class-leading engine performance.
The bilateral beam frame is all-new with an optimized engine mounting position to improve the machine’s rigidity balance, resulting in improved cornering ability and traction. Redesigned bodywork and ergonomics provide a lighter and more compact feel with easier rider movement. The class leading KYB suspension with updated internal components provides the optimal balance between comfort and race-winning performance.
Yamaha’s Power Tuner App
Yamaha’s Power Tuner App – 250cc Version
Yamaha is breaking new ground in the industry again, with the 2019 YZ250F becoming the world’s first production 250cc motocross bike with a wireless smartphone based engine tuner. Yamaha introduced the Power Tuner app, which brings the power of the GYTR Power Tuner to your iOS or Android device. Using Wi-Fi to connect to the bike’s onboard CAN-bus network via a Communication Control Unit (CCU), the app allows owners to adjust air/fuel mixture and ignition timing maps to tune engine performance for track conditions, record race log information, and monitor a range of data such as maintenance and system diagnosis, engine run time, and more.
The Yamaha Power Tuner App, first released with the 2018 YZ450F, makes it possible to modify engine mapping in greater detail than previously possible. It also allows users to share settings among their team or with friends (along with other information), thus evolving the system into a tool that facilitates group communication.
Dual-Mode Switchable Engine Mapping
Yamaha’s Dual-Mode Switchable Engine Mapping
Two-mode adjustable engine mapping allows the rider to adjust engine character with the push of a button, making it easy to tune the YZ250F for changing track or weather conditions.
YZ250F Electric Start
The YZ250F Now Comes With Electric Start
Utilizing a compact starter motor and ultra-lightweight lithium-ion battery, the 2019 YZ250F brings the convenience of push-button starting to the racetrack for quick and effortless restarts under pressure, and relaxed riding when the clock isn’t ticking. Powered by a high-capacity and ultra-lightweight lithium-ion battery, the system adds minimal weight.
New 2019 Yamaha YZ250F Engine Updates
The 2019 Yamaha YZ250F Engine
For 2019, Yamaha has refined its distinct rearward-slanted-cylinder design for the YZ250F engine. The liquid-cooled, DOHC 4-valve, fuel-injected engine features a forward-positioned straight downdraft intake with symmetrical intake and exhaust ports. Fuel is delivered by a lighter 44mm throttle body, through a new 12-hole Denso injector. A new, higher-compression flat-top forged piston features a bridge-box design for additional strength with minimal weight. The piston, rings and DLC-coated piston pin, along with the offset cylinder configuration, all reduce friction loss and contribute to quick response.
The engine’s intake ports, cam profiles, high-strength connecting rod and optimized crank and counterbalancer all work together to produce more potent mid-to-high-rpm power with user-friendly delivery and exceptional reliability. The new cylinder is also lighter and angled more upright to improve mass-centralization.
The 2019 YZ250F’s transmission and clutch were also overhauled for a more direct connection as well as enhanced durability. The gears and shift drum have been revised for lighter weight, and the dogs and shift mechanisms are designed to smooth gear changes and improve durability under the heavy demands of motocross racing. A larger-diameter clutch is also a new feature, designed to improve feel and boost reliability even further under high-heat conditions.
The radiators and exhaust system have also been modified for improved performance and weight distribution. The updated radiators are larger and angled more directly into the incoming air stream for improved cooling under the most demanding race conditions. The innovative wraparound exhaust pipe design improves mass concentration and improves power development, with revised geometry for 2019. The new layout moves the rear end of the exhaust pipe farther forward and enables a muffler position closer to the bike’s center of mass.
2019 Yamaha YZ250F Updated Frame and Ergonomics
New Frame and Optimized Ergonomics
The compact bilateral beam frame is completely new for 2019, and it further refines the instinctive feel that makes this Yamaha the best handling machine in the class. Designed to improve contact to the ground and provide the best possible balance of stiffness for bump absorption and effortless cornering, the all-new frame features a redesigned swingarm pivot area along with redesigned upper frame bracing and rear frame spars. All-new engine mounts that centralize mass and increase rigidity on lateral, horizontal and vertical axis help to provide an ideal balance between cornering feel and straight-line rigidity.
Slimmer and more comfortable seat and bodywork
New compact bodywork and seat
Surrounding the fully redesigned chassis, the 2019 YZ250F features a new lighter, compact body from tip to tail. The radiator shrouds incorporate a new air duct with a concave shape that not only improves styling but is also narrower for better knee grip and overall rider movement. The seat height has been reduced by 8mm towards the front and almost 20mm lower at the tail end, giving the rider better maneuverability on the bike.
Easily Tuned KYB Coil Spring Suspension
The industry-leading, fully adjustable KYB coil spring-type forks with speed sensitive damping receive updated settings, larger pistons and newly designed fork lugs/axle brackets to provide exceptional balance between handling and bump absorption for race-winning performance. The KYB shock boasts new damping characteristics to match the new chassis as well as a new, lighter-weight spring. The reservoir has been increased 30cc to increase damping control during long motos.
Lighter Wheels
Careful computer-aided refinement of the EXCEL rim’s cross-sectional profile shaves valuable un-sprung weight without sacrificing durability, while wheel collars with increased rigidity provide an improved feeling of contact to the ground when braking and a clear feeling of traction.
2019 YZ250F Price, Color and Availability
Available in either Team Yamaha Blue or White color schemes, complete with the onboard Communication Control Unit (CCU) and the Yamaha Smartphone Power Tuner App, the all-new 2019 Yamaha YZ250F will arrive at Yamaha dealers beginning in June 2018 with a MSRP of $8,199.
The 2019 Yamaha YZ250F Looks Sharp
