YZ125
125cc Lightweight 2-Stroke
The YZ125 represents an important evolution in Yamaha’s two-stroke lineage. Yamaha engineers put considerable thought into developing a motorcycle that would be both dominant on the racetrack and user-friendly for developing riders looking to bridge the gap between recreation riding and competitive motocross.
The liquid-cooled 125cc two-stroke engine has been thoroughly reworked to produce more power than previous generations. Every functional part of the YZ125 engine is new, including the cylinder body, cylinder head, piston, piston pin, connecting rod, crankcase and expansion chamber.
To match increased engine performance, an updated lightweight braking system features larger front pistons, a more rigid caliper, a redesigned 270mm front rotor with a 30% increase in pad contact area and higher friction pad material, all combining to provide exceptional braking power and feel.
Model Features
Increased Power and better usability
The all-new 125cc 2-stroke engine is the most powerful unit ever used on the YZ125, and it develops a higher performance in the mid to high rpm range and offers improved usability. This has been achieved by developing an all new cylinder head, piston and cylinder, con rod, crank, YPVS as well as redesigning other major components.
Athletic New Ultra-slim bodywork
The bodywork is the slimmest ever, with
the area between the rider’s knees 36mm
narrower than on the previous model, and
the athletic and modern body design
underlines the YZ125’s lightness and
compactness. The reduced dimensions
improve overall rider mobility and
reinforce the feeling of agility.
High-efficiency air intake
Following extensive testing Yamaha’s
engineers have developed a new intake
system. The whole area around the airbox
has been redesigned including the seat
base, rear frame and sidepanels in order
to reduce air resistance, making a
significant contribution towards increased
intake efficiency.
Keihin Powerjet Carburettor
The YZ125 is equipped with a Keihin PWK
38.1mm carburettor featuring a solenoid
controlled Powerjet that instantly delivers
its fuel/air mix for even more explosive
performance, giving a real advantage out of
the gate and when accelerating hard out of
corners. And the new TPS (Throttle Position
Sensor) and 3D map controlled CDI ensure
optimised ignition timing, while the new VForce
reed valve assembly provides optimum
intake efficiency at all engine speeds.
Smooth Shifting 6-speed transmission
The transmission has been redesigned and
features a new set of internals to handle
the YZ125’s dramatically increased
maximum power output, and a redesigned
shift mechanism gives a smoother shift
feeling. The secondary reduction ratio is
slightly increased with the use of a 13/49
front/rear sprocket set, and for better
driveability the transmission runs with
slightly reduced 5th and 6th gear ratios.
Best-in-class KYB Suspension
Yamaha’s SSS (Speed Sensitive System) KYB front forks are widely regarded as being amongst the best designs available on a production motocross bike, and the new model features revised low speed damping settings on both the front and rear suspension systems for better handling characteristics.
New Rear Frame
Complimenting the performant aluminium semi-double cradle frame, the new rear frame on the YZ125 is designed to enhance air flow into the carburettor, and a new style cross member facilitates the use of a new single bolt fixing for the seat – for quicker and easier maintenance. The new rear frame also accommodates a new mounting point for the 50mm shorter silencer.
*PLEASE NOTE: Pricing and specifications are subject to change
