KEY FEATURES - Powerful New 125cc Two-Stroke Engine
- Improved Fueling
- New Brake System
- Revised Suspension Damping
- Improved Rider Ergonomics
- Bold New YZ Styling
- 18-inch rear wheel and large rear sprocket
- Adjustable, tapered aluminum handlebar
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ENGINE -
Powerful New 125cc Two-Stroke Engine
- A completely redesigned liquid-cooled 125cc two-stroke engine boasts improved usability and increased mid- and top-end power over the 2022 model for a thrilling new level of performance.
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Improved Fueling
- New high-precision Hitachi Astemo® Keihin PWK38S carburetor features a power jet, throttle position sensor and 3D-map-controlled CDI unit for precise ignition timing. The result is clean, crisp throttle response, superior rideability and excellent over-rev character.
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Ceramic composite cylinder bore is a linerless design with the ceramic coating sprayed directly on the aluminum block.
- reduced weight (no heavy iron liner)
- reduced friction
- extended cylinder life
- excellent heat dissipation for consistent power delivery
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Specially designed combustion chamber achieves a more complete burn at higher rpm.
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Lightweight, flat-top forged aluminum piston.
- excellent durability
- light weight means fast engine response
- matches combustion chamber design for maximum power delivery
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Lightweight, ball-bearing-style crank.
- lightweight design for fast throttle response
- friction-reducing crank seals
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Compact crankcases.
- lightweight design
- helps centralize mass
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Quick-access, magnesium outer (sub) clutch cover.
- lightweight design
- speeds clutch access
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Close-ratio, 6-speed transmission uses optimized gear ratios.
- ratios are matched to engine output for maximum performance
- optimal hook-up for outstanding acceleration and corner-exiting power
- transmission features "involute splines" for smooth, positive shifting even under power
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Yamaha's patented YPVS system.
- features a slide (guillotine) type power valve that provides the benefits of both solid, low-rpm power delivery combined with a strong top-end punch. This system varies the exhaust port height and timing based on engine rpm.
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6-petal, carbon fibre reed design.
- for stronger high-rpm performance with greater over-rev capacity
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CD (capacitor discharge) ignition system.
- delivers a precise spark for fast, sure starts
- ensures optimal timing at all rpm for fast, strong response
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High-capacity, washable, dual-stage, foam air filter.
- excellent filtering qualities
- reusable filter reduces maintenance costs
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Large-capacity, dual radiators feature 10-row cores.
- maximum cooling efficiency
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Lightweight exhaust system features a re-packable aluminum silencer which allows the rider/tuner to maintain the correct amount of back pressure for maximum engine performance while reducing noise.
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Works-style clutch lever and race-spec barrel adjuster.
- easy lever pull
- for on-the-fly clutch adjustments
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CHASSIS/SUSPENSION -
Lightweight, aluminum, semi-double-cradle frame.
- combines with compact engine to provide an awesome power to weight ratio
- obvious benefit of an aluminum frame is a significant weight reduction
- Yamaha maintains semi-double cradle design because it offers an excellent rigidity balance between lateral and torsional rigidity while offering controlled flex in the longitudinal plane
- result is a light aluminum frame, which provides excellent handling, good ride quality, excellent stability and responsive cornering performance
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Removable rear subframe.
- constructed of square-section, lightweight aluminum
- detachable design allows easy access when servicing rear suspension components
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Lightweight, tapered design aluminum swingarm.
- produced by "hydro forming", a forming method that uses high pressure water to form shapes
- excellent rear wheel traction and control
- lightweight design
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Cast aluminum upper and forged lower triple clamps.
- strong yet lightweight
- fast, agile handling
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Adjustable handlebar mounts.
- handlebar can be moved 10 mm rearward if desired
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"Speed Sensitive System" 48 mm, adjustable, inverted, "twin chamber" KYB fork. Front wheel travel is 300 mm (11.8").
- fork adjustments include: 20-way compression damping and 20-way rebound damping
- optional fork springs are available through Genuine Yamaha parts
- low-friction fork seals provide reduced stiction for a smoother stroke
- twin-chamber design means the damper unit is in a separate structure which prevents aerated fork oil from entering the inner damper assembly and degrading its damping abilities
- the inner damper is pressurized, it also eliminates bubbles forming in the oil
- "Speed Sensitive" design means the damping force is controlled by piston speed, not position in the fork
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Fork also features a Transfer Control Valve (TCV).
- TCV enhances damping from mid to full stroke and improves bottoming characteristics
- TCV offers more precise control throughout the full suspension stroke
- TCV is located on the upside of the spring and its function is controlled by piston speed, not piston position, hence the term "Speed Sensitive System fork"
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Large wrap-around plastic fork protectors.
- provide excellent protection from dirt, mud and stone chips
- self-supporting design reduces friction for smoother stroke
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Monocross link rear suspension features a fully adjustable, KYB piggyback shock which provides 315 mm (12.4") of wheel travel.
- features separate adjusters for high- and low-speed compression damping
- adjustments include: spring preload, 20-way rebound damping, 20-way low-speed compression damping and 2 turns of high speed compression damping
- 18 mm damper rod
- Kashima coating (friction reducer) is used in the shock body and sub tank to reduce friction and improve suspension performance
- piggyback shock utilizes a full rebound oil lock system for excellent suspension function and great ride quality.
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270 mm floating front disc brake with Nissin twin piston caliper.
- "wave" style rotor (disc) reduces weight, improves cooling (more surface area) and improves styling
- braking performance is excellent with great feel and control
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"Shorty" front brake lever is adjustable for various hand sizes.
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245 mm rear disc brake with single piston caliper.
- integrated master cylinder (fluid reservoir is integrated into the top of the master cylinder)
- "wave" style rotor (disc) reduces weight, improves cooling (more surface area) and improves styling
- strong stopping power with excellent feel and control
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Rugged, plastic rear caliper and lower rear disc protectors / guards.
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Sun Star-brand rear sprocket.
- increases the contact area between the sprocket and chain rollers
- reduces the load on the chain and increases service life of chain and sprocket
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Lightweight, D.I.D. 21" front and 18" rear rims and premium Dunlop tires.
- provide excellent durability
- reduces unsprung weight for optimal suspension performance and handling
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Flat-design seat features multi-density foam.
- provides good initial softness/comfort and then increases the firmness as more pressure is applied
- "pebble" finish on the top and side surfaces provides excellent rider grip and durability
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Seat, handlebar and fuel tank ergonomics provide excellent freedom of movement for the rider.
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DETAILS -
Cross Country Ergonomics
- A racy "gripper"-type seat and narrow fuel tank combined with a tapered aluminum handlebar and adjustable mounts create greater freedom of movement and more comfortable ergonomics for riders.
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Cross Country Features
- The YZ125X is focused on enduro competition with an 18-inch rear wheel, larger rear sprocket, side stand, sealed O-ring chain, reserve fuel petcock, and newly adopted scraper between the fork's dust and oil seal, all adding up to exceptional cross country performance.
- Slim design, modern aggressive bodywork allows easy rider movements
- Lightweight YZ250F/450F-based wide footpegs provide excellent grip & ground clearance
- Heavy-duty 520 gold anodized "O" ring chain
- Rugged chain guide helps prevent the chain from de-railing & also helps protect the rear sprocket
- Serrated rear brake lever & folding shift lever tip
- Stainless steel, inner clutch cable provides excellent strength, smooth action & long life
- E10 friendly fuel system components
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POWERFUL 125 CC ENGINE
LIGHTWEIGHT ALUMINUM FRAME
CROSS COUNTRY- SPECIFIC FEATURES
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The YZ125X sets the standard for light, fast two-stroke fun! The perfect entry into the world of XC and enduro competition, this two-stroke trailblazer combines thrilling performance and ultimate reliability for all your wins.