Two Stroke Evolution

More powerful, more capable, more advanced. Offering the ideal blend of performance, reliability and usability to develop the skills to win.

Powerful Two-Stroke YZ125 Engine

Yamaha's advanced, liquid-cooled 125cc two-stroke engine is ready for competition straight out of the box with Yamaha's patented Power Valve System (YPVS) providing impressive acceleration, thrilling mid-to high-rpm power, along with supreme usability.

Lightweight Rider-Friendly Chassis

The lightweight finely tuned chassis means nimble handling, more control and less rider fatigue. A race-proven, highly developed aluminum semi-double cradle frame is engineered to provide just the right amount of strength and flex for the perfect balance of stability and cornering performance. Removable aluminum rear subframe is constructed of square-section tubing for reduced weight.

Premium KYB® Suspension

The YZ125's renowned suspension performance offers unmatched levels of control, capability and comfort. The class-leading Speed Sensitive System 48mm inverted KYB™ fork includes a leaf spring in the mid-speed valve for more precise damping and increased performance. The fully adjustable KYB rear shock features reduced-friction Kashima Coat internals, separate adjusters for high and low-speed compression damping, and a full lock oil rebound system for enhanced comfort. It all adds up to class-defining suspension and handling characteristics.

Race-Ready Features

Complete with adjustable aluminum handlebars, water-resistant PVC handle bar pad, wide foot pegs, gripper seat, adjustable clutch lever with works-style cable adjuster and lightweight rear sprocket design, the YZ125 is competition-ready straight out of the crate.

Key Features New For 2026

Updated CDI settings optimize combustion for more linear power delivery and enhanced rideability.

Updated air intake and intake boot design yield a more seamless connection and smoother airflow.

Revised carburetor setting for more consistent performance in varied conditions.

Engine

Yamaha's advanced, liquid-cooled 125cc two-stroke engine provides impressive power and supreme usability.

Patented Yamaha Power Valve System combines crisp bottom-end torque with potent mid-range and free-revving top-end.

High-precision Hitachi Astemo® Keihin PWK38S carburetor provides clean, crisp throttle response and superior rideability.

Digital CDI system delivers precise spark and monitors engine speed to ensure optimal timing for faster, stronger response.

Close-ratio six-speed transmission has wider gear tooth width and optimized gear ratios for maximum performance.

High-capacity radiator with dark louvers deliver maximum cooling efficiency and an aggressive look.

Chassis/Suspension

Lightweight finely tuned chassis means nimble handling, more control and less rider fatigue.

Premium Bridgestone® Battlecross X20 tires offer strong cornering grip and race-developed performance.

High performance braking system features a 270mm front and 240mm rear rotors offering exceptional braking power and feel.

Fully adjustable KYB® shock provides exceptional rear wheel control and class-leading capability.

Best-in-class Speed Sensitive 48mm KYB® fork includes a leaf spring in the mid-speed valve for unmatched performance.

Removable aluminum rear subframe is constructed of square-section tubing for reduced weight.

Race-proven aluminum semi-double cradle frame is engineered to provide the perfect balance of strength and flex.

Specifications

Engine

Engine Type - 125cc liquid-cooled 2-stroke; reed-valve inducted

Bore x Stroke - 54.0mm x 54.5mm

Compression Ratio - 8.2~10.1:1

Fuel Delivery - Hitachi Astemo® Keihin PWK38S carburetor

Transmission - Constant-mesh 6-speed; multiplate wet clutch

Final Drive - Chain

Fuel Capacity - 1.8 gal

Chassis

Suspension/Front - KYB® Speed-Sensitive System inverted fork; fully adjustable, 11.8-in travel

Suspension/Rear - KYB® single shock; fully adjustable, 12.4-in travel

Brakes/Front - Hydraulic disc, 270mm

Brakes/Rear - Hydraulic disc, 240mm

Tires/Front - 80/100-21 Bridgestone® Battlecross X20F

Tires/Rear - 100/90-19 Bridgestone® Battlecross X20

Dimensions

LxWxH - 84.1 in x 32.5 in x 51.0 in

Seat Height - 38.6 in

Wheelbase - 56.9 in

Rake (Caster Angle) - 26°

Trail - 4.3 in

Max. Ground Clearance - 14.4 in

Fuel Capacity - 1.8 gal

Wet Weight - 212 lb

Other

Warranty - 30 Day (Limited Factory Warranty)