Key Features
- YZ125 two-stroke engine with Yamaha Power Valve System (YPVS)
- Model-specific CDI unit
- Racing intake system
- Ultra-lightweight YZ125-spec frame
- Industry-leading, XC-specific adjustable KYB suspension
- Smooth shifting, 6-speed, close ratio transmission
- YZ125 two-stroke engine with Yamaha Power Valve System (YPVS)
- Model-specific CDI unit
- Racing intake system
- Ultra-lightweight YZ125-spec frame
- Industry-leading, XC-specific adjustable KYB suspension
- Smooth shifting, 6-speed, close ratio transmission
- "Gripper" type seat and narrow fuel tank
- Adjustable, tapered aluminum handlebar
- 18-inch rear wheel and large rear sprocket
|
Engine -
Liquid-cooled, 125 cc, crankcase reed valve-inducted 2-stroke engine provides class leading power and acceleration.
- super crisp, instant "right now" engine power (when in the powerband)
- easy and economical to maintain, service and rebuild
-
7.5-degree cylinder angle and straight shot intake path through the combustion chamber.
-
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
-
Specially designed combustion chamber achieves a more complete burn at higher rpm.
-
Lightweight, flat-top forged aluminum piston.
- excellent durability
- light weight means fast engine response
- matches combustion chamber design for maximum power delivery
-
Lightweight, ball-bearing-style crank.
- lightweight design for fast throttle response
- friction-reducing crank seals
-
Compact crankcases.
- lightweight design
- helps centralize mass
-
Quick-access, magnesium outer (sub) clutch cover.
- lightweight design
- speeds clutch access
-
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
-
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.
-
Mikuni TMXx38 carburetor features a "D" slide design.
- enhances overall power delivery
- provides crisp throttle response at all rpm
-
6-petal, carbon fibre reed design.
- for stronger high-rpm performance with greater over-rev capacity
-
CD (capacitor discharge) ignition system.
- delivers a precise spark for fast, sure starts
- ensures optimal timing at all rpm for fast, strong response
-
High-capacity, washable, dual-stage, foam air filter.
- excellent filtering qualities
- reusable filter reduces maintenance costs
-
Large-capacity, dual radiators feature 10-row cores.
- maximum cooling efficiency
-
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.
-
Works-style clutch lever and race-spec barrel adjuster.
- easy lever pull
- for on-the-fly clutch adjustments
|
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
-
Removable rear subframe.
- constructed of square-section, lightweight aluminum
- detachable design allows easy access when servicing rear suspension components
-
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
-
Cast aluminum upper and forged lower triple clamps.
- strong yet lightweight
- fast, agile handling
-
Adjustable handlebar mounts.
- handlebar can be moved 10 mm rearward if desired
-
"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
-
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"
-
Large wrap-around plastic fork protectors.
- provide excellent protection from dirt, mud and stone chips
- self-supporting design reduces friction for smoother stroke
-
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.
-
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
-
"Shorty" front brake lever is adjustable for various hand sizes.
-
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
-
Rugged, plastic rear caliper and lower rear disc protectors / guards.
-
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
-
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
-
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
-
Seat, handlebar and fuel tank ergonomics provide excellent freedom of movement for the rider.
|
Details
- 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
|
Shop New 
Light, fast and fun! The high performance two-stroke entry into the world of XC and enduro competition. Designed to be the perfect stepping stone toward a full size cross-country machine, the YZ125X is the pinnacle of lightweight, two-stroke performance on the race course.