The liquid-cooled, DOHC 4-valve, 250cc fuel-injected engine features a forward-positioned straight downdraft intake with symmetrical intake and exhaust ports. A new higher-compression piston and new valves deliver outstanding engine character with a focus on top-end power delivery, and the lighter cylinder is more upright to improve mass-centralisation
Exclusive Power Tuner App
Like the flagship YZ450F, the all-new YZ250F now features a Communication Control Unit (CCU) as standard. Using the Power Tuner app, you can 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, diagnosis, run time, and more.
New ECU map switch
The new two-mode switchable engine mapping allows you to instantly adjust engine character ‘on the fly’ with the push of a button, making it easy to fine tune the YZ250F for changing track or weather conditions while riding, or in between motos or practice sessions.
Lightweight electric starter with lithium-ion battery
Mounted near the chassis centre to maintain a good weight balance, the YZ250F’s light and compact new electric starter system ensures instant restarts during races and saves you time and effort. Powered by a high-capacity and ultra-lightweight four-cell lithium-ion battery, the system adds minimal weight.
Compact new body and seat design
The YZ250F features new bodywork from tip to tail, including a new compact fuel tank specifically designed for motocross demands. In addition to shaving weight, the new body design is narrow for more comfortable knee grip and feeling of control, and the seat is updated to give the rider additional room to move aboard the machine.
New bilateral beam frame
The YZ250F’s all-new bilateral beam frame further heightens the sense of agility to make the new model one of the best handling bikes in its class. Larger upper frame bracing improves rigidity and durability, while wider rear frame spars and all-new engine mounts centralise mass for the best possible balance of bump absorption, stiffness and feeling of grip.
Larger diameter KYB® coil spring-type forks give optimised rigidity for improved feel – while a refined speed-sensitive damping mechanism provides exceptional balance for race-winning handling. A new lightweight KYB® rear shock has been developed for the new chassis and features an increased reservoir capacity for more controlled damping characteristics.
New lighter-feeling clutch
To match the new engine, the 2019 YZ250F is equipped with an all-new clutch with a reduced spring load, giving a much lighter feel at the clutch lever, with excellent operational feel at half clutch. Featuring much thicker friction plates, this heavy-duty clutch ensures enhanced performance, excellent controllability and increased durability.
Updated radiator design
New larger radiators are angled more directly into the incoming air flow for improved cooling under the most demanding race conditions. Inside the engine the water pump is equipped with a new aluminium impeller, and features rerouted coolant pipes that enhance durability under the toughest racing conditions
New axle brackets & wheel collars
To give improved feedback from the track surface when braking, the YZ250F’s new forks are fitted with larger front axle brackets featuring new shape wheel collars that ensure a higher level of front end rigidity. The increased sensitivity enables you to assess the front wheel traction levels more accurately, giving you greater control.
New cam chain assembly
To accommodate the engine’s higher performance, there’s a new high specification cam chain guide manufactured from Hydrogenated Nitrile Butadiene Rubber (HNBR), giving excellent mechanical strength and high resistance to heat, oil and pressure. Featuring a newly designed tensioner, the new assembly reduces the load and offers greater stability.
4-stroke, liquid-cooled, DOHC, 4-valves
Bore X Stroke
77 mm x 53.6 mm
13.8 : 1
Fuel Tank Capacity
Constant Mesh, 5-speed
2,175 mm x 825 mm x 1,285 mm
Tyre Size Front
80/100 - 21 51M
Tyre Size Rear
100/90 - 19 57M
Brakes Type Front
Hydraulic single disc 270 mm
Brakes Type Rear
Hydraulic single disc 245 mm