First Look | 2015 Yamaha YZ Model Line

2015 Yamaha YZ450F

The 2015 motocross machines continue to roll out, with images of Yamaha’s line of YZ and YZF racers being the latest to reach the public. After last year’s complete overhaul of the YZ250F and YZ450F, two bikes that have proven themselves over the last month’s professional races, it is the YZ two-stroke line that sees the bulk of the Japanese brand’s attention. Years of complaints on the dated styles of the YZ125 and YZ250 have finally been addressed, as both bikes receive full makeovers with new body kits.

Have a look at the full galleries of each bike, from the mini YZ85 to the YZ450F.
For more information, visit yamaha-motor.com.

2015 Yamaha YZ250F

Liquid-cooled, DOHC 4-valve, fuel-injected engine with the same forward-positioned, straight intake, rear-inclined cylinder, and rear-positioned exhaust layout as the YZ450F.The 4-titanium-valve cylinder head is matched to a fuel injection system that provides power at mid-to-high rpm. The fuel injection system instantly adjusts the air/fuel mixtures depending on altitude and temperature, for a hesitation-free engine that delivers no matter the conditions.

The aluminum Bilateral Beam frame offers a superb rigidity balance and provides unmatched lightweight handling.

The exhaust pipe has an innovative layout, circling the cylinder, giving the exhaust pipe proper length for an excellent exhaust pulse effect. At the same time, the exhaust pipe has three different diameters throughout the exhaust tract, bringing out excellent power characteristics. This layout allows the silencer behind the side panel, making it closer to the middle of the bike for centralized mass for superior handling.

The layout of the seat, fuel tank, air box, and wrap-around exhaust system moves the bike's mass towards the center for exceptional handling. The front intake layout with large air filter element adds the benefit of reduced air filter maintenance due to its positioning away from dirt roost from the rear wheel.

Accessory GYTR® Power Tuner lets owners adjust air/fuel mixture and ignition timing maps to match engine performance characteristics to the rider and track conditions in a matter of seconds with the push of a few buttons.

New for 2015:

New front fork settings offer greater performance in the mid-to-end stroke

Quick-release quarter-turn Dzus® air box fasteners for tool-less access to the air filter.

Engine

A liquid-cooled, DOHC 4-valve, fuel-injected engine with the same forward-positioned straight intake, rear-inclined cylinder and rear-positioned exhaust layout as the YZ450F. The engine, with its straight and symmetrical intake and exhaust ports and compact, high-compression combustion chamber, delivers outstanding engine character in the highspeed range.

The adjustable fuel injection system uses a 44mm throttle body fed by a high-pressure battery-less electric fuel pump. This ensures optimum fuel atomization and air/fuel calibration for excellent rideability in a wide range of riding conditions. The system controls the volume of fuel injected and the ignition timing based on engine rpm and throttle opening, providing hesitation-free response and controllability.

Various detailed design measures are adopted to reduce horsepower loss. The forged 2-ring piston is light weight and is cooled by an oil spray jet. In addition, the compression ring is a single-ring design instead of the conventional two ring. This piston and rings, along with the offset cylinder configuration, reduce friction loss and contribute to quick response. What's more, the specs for the intake/exhaust ports, cam profiles, ECU, carburized crank, optimized balance ratios for the crank web, transmission, clutch design, and other features, all work together to create the YZ250F's outstanding engine character with power output in the high-rpm range.

As with the YZ450F, an innovative exhaust pipe design is adopted to increase mass centralization and improve power development characteristics. This layout moves the rear end of the exhaust pipe farther forward and enables a muffler position close to the center of the mass. Adjustments are made in the pipe diameter in its various sections resulting in excellent exhaust pulse effect that contributes to high rpm power output.

The compact wet sump lubrication system with piston cooler spray jet maintains excellent engine durability and eliminates the need for an oil tank, which lowers engine weight. This creates a more compact engine that contributes to mass centralization and unmatched handling.

The transmission and shift mechanisms reduce drive-force loss during gear changes and produce smoother shift operations and surer shift action.

Chassis/Suspension:

The aluminum muffler is positioned closer to the machine's center of gravity as it is almost completely hidden by the side number plate. The layout contributes to centralized mass for a lightweight handling feeling.The front suspension has proven KYB® air-oil separated forks with stiffer fork springs, new valving and a new fork outer tube to improve performance in the mid-to-end stroke and aid fork bottoming resistance. The rear suspension also features settings optimized for ideal damping characteristics to match the chassis dimensions.

The large diameter 22mm front axle and top triple clamp increases rigidity for excellent handling and front end feel. The handlebar mounts are rubber mounted to improve comfort and reduce handlebar vibration.

The air filter is positioned away from the rear wheel which means less maintenance for the rider.

Additional Features:

"In-mold graphics" technology is a method in which the graphics are molded into the radiator shrouds for improved decal durability and reduced scratches.Riders have a choice of two color options: Team Yamaha Blue/ White or White/Red.

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2015 Yamaha YZ450F

YZ450F's revolutionary rearward-slanted-cylinder design is an innovative approach to achieve unmatched mass centralization. Concentrating the motorcycle's heaviest components (engine mass, fuel tank, exhaust system, and airbox) toward the center of the machine, as well as the rotational mass of the valve train, helps achieve superior, nimble handling.

The 4-titanium-valve cylinder head is matched to a fuel injection system that provides superb power feeling across the rpm range. The adjustable fuel injection system uses a 44mm throttle body fed by a high pressure battery-less electric pump to ensure optimum fuel atomization and air/fuel calibration for a wide range of riding conditions. The YZ450F instantly adapts to changing air/fuel mixtures depending on altitude and temperature, for an engine that delivers no matter what conditions.

The aluminum Bilateral Beam frame features new motor mounts to improve the machines handling character and offers a superb rigidity balance and, with class-leading front and rear suspension, provides unmatched lightweight handling and cornering.

Industry-leading suspension with refinements to internal and external components and settings result in superior handling.

Accessory GYTR® Power Tuner lets owners adjust air/fuel mixture and ignition timing maps to match engine performance characteristics to the rider and track conditions in a matter of seconds with the push of a few buttons.

New for 2015:

Stiffer fork springs, new valving and a new fork outer tube improve performance in the mid-to-end stroke and aid fork bottoming resistance.

Quick-release quarter-turn Dzus® air box fasteners for tool-less access to the air filter.

A new steel bottom engine bracket has been designed for increased rigidity balance and damping feel.

New Dunlop® MX52 tires offer excellent traction front and rear, especially on hard surfaces.

Engine:

The high-performance ECU provides great bottom end torque plus delivers a strong feeling of power from 3rd gear up while the gear ratios lengthen the powerband and heighten the feeling of power in 2nd and 3rd gear.

The valve mechanisms and cylinder head feature specs that take performance to the next level, resulting in added power and outstanding performance.

The exhaust pipe has an innovative layout, circling the cylinder, giving the exhaust pipe proper length for an excellent exhaust-pulse effect. At the same time, the exhaust pipe has three different diameters throughout the exhaust tract, bringing out excellent power characteristics. This layout allows the silencer to be behind the side panel closer to the middle of the bike which centralizes the mass for superior handling.

The compact wet sump lubrication system with piston cooler spray jet eliminates the need for an oil tank, reducing engine weight. The water pump employs a plastic resin impeller for further weight reduction. The reduced size of the crankcase enabled by this lubrication system design is a major factor in making it possible to mount the 450cc engine on the compact frame to deliver precise and instinctive handling.

The accessory GYTR Power Tuner can simplify the work of adjusting fuel injection volume and ignition timing settings to fit personal preferences or track conditions.

Chassis/Suspension:

A Bilateral Beam frame is adopted and the overall dimensions are roughly the same as the frame of the 2013 YZ250F. This gives the YZ450F a compact chassis that provides the most instinctive handling in the 450 motocross class.

The aluminum muffler is positioned closer to the machine's center of gravity as it is almost completely hidden by the side number plate. The layout allows a shorter, lighter sub frame and also contributes to mass centralization for lightweight handling feel.
The front suspension has proven KYB® air-oil separated forks with stiffer fork springs, new valving and a new fork outer tube to improve performance in the mid-to-end stroke and aid fork bottoming resistance. The rear suspension also features settings optimized for ideal damping characteristics to match the chassis dimensions.

The large diameter 22mm front axle and top triple clamp provide rigidity for unmatched handling and front end feel. The handlebar mounts are rubber mounted to improve comfort and reduce handlebar vibration.

The fuel tank and air cleaner box give the machine a slimmer feeling between the legs as well as positions the fuel tank mass closer to the center of the bike which improves handling feel. Furthermore, the air box can be accessed without removing the fuel tank for easy serviceability of the large air cleaner element.

A narrow radiator design contributes to slimming down the radiator panel area.

Additional Features:

Riders have a choice of two color options: Team Yamaha Blue/ White or White/Red.

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PAGE TWO: 2015 YZ125 & YZ250
PAGE THREE: 2015 YZ85

No, the YZ line did not receive direct injection, a reverse engine, or any other massive new-age overhaul. Instead we see the same proven package Yamaha perfected for years on end, with its aluminum frame, Kayaba SSS suspension, and more. The new body lines of the YZ range are styled after the edges, creases, and curves carved onto the four-stroke YZF machines.

2015 Yamaha YZ125

Modern, aggressive styling, including new front fender, front number plate, radiator shrouds, side number plates, air box, rear fender, fork guards, as well as some technical changes to the rear sprocket, rear brake disc protector, and rear brake caliper protector and wider foot pegs just like the 4 strokes.

A light aluminum frame housing an amazingly light and compact engine results in an awesome power-to-weight ratio.

The YZ125 is ready to race out of the crate, complete with an aluminum handlebar, titanium foot pegs, and gripper seat.

A pure motocross machine, the light and nimble YZ125 is the perfect choice for riders stepping up from the 85cc class.

Ultra lightweight means nimble handling with less fatigue.

New for 2015:

Modern, aggressive new styling for 2015 looks awesome.

The latest generator KYB® Speed-Sensitive fork just like the 4-stroke machines has been added and provides industry leading performance.

A clutch lever position adjuster is adopted to allow adjustments based on rider preferences and accommodates differing hand sizes.

The latest Dunlop MX52® tires are used for the best off-road traction, performance and reliability.

Engine:

Amazingly compact 124cc reed-valve-inducted two-stroke helps produce an awesome power-to-weight ratio.

Reed-valve spacer improves acceleration across the entire powerband.

Patented YPVSTM power-valve system combines crisp, hard-hitting bottom-end acceleration with strong midrange and eye-opening top-end.

Six-speed, close-ratio transmission optimizes gear ratios for maximum performance.

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

Large-capacity radiator features a 10-row core with four louvers to deliver maximum cooling efficiency at all performance levels.

Trick, works-style clutch lever features race-spec barrel adjuster for on-the- fly adjustability.

Chassis/Suspension:

YZ250F-style front-brake caliper and wave-style front and rear discs minimize unsprung weight and provide excellent stopping power.

A carefully engineered, advanced aluminum frame and swingarm give the YZ125 the best handling in its class.

Speed-Sensitive System 48mm KYB® fork; damping force is controlled by piston speed which provides a smoother, more precise ride with 11.8 inches of travel.

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

Rear, fully adjustable KYB® shock features a steel shock spring and reduced-friction Kashima coating of internals. 12.4 inches of travel, separate adjusters for high- and low-speed compression damping, and a full lock oil rebound system for increased comfort all add up to fantastic rear wheel control and a sweet ride.

Tapered rear wheel spacers ease sliding the rear wheel into place for quicker tire changes.

Premium Dunlop® knobbies offer race-spec traction and wear.

Additional Features:

Special-design "gripper" type seat and fuel tank, forward-canted steering crown and low aluminum handlebar all help create greater freedom of movement and more comfortable ergonomics for riders.< Wide, cleated, folding titanium foot pegs are lightweight and provide excellent comfort, grip and ground clearance. Use of lightweight box-head bolts throughout the chassis eases maintenance while reducing weight for increased performance. Wide-diameter fuel tank cap for easier refueling. Repackable exhaust silencer. [shareprints gallery_id="1000370937" gallery_type="thumb_slider_desc" gallery_position="pos_center" gallery_width="width_100" image_size="xlarge" image_padding="0" theme="dark" image_hover="false" lightbox_type="slide" titles="true" captions="true" comments="false" descriptions="true" sharing="true"]  

2015 Yamaha YZ250

Modern, aggressive styling, including new front fender, front number plate, radiator shrouds, side number plates, air box, rear fender, fork guards, as well as some technical changes to the rear sprocket, rear brake disc protector, and rear brake caliper protector and wider foot pegs just like the 4 strokes.

A light aluminum frame housing a patented YPVS™ Power valve-equipped ripper of an engine results in an awesome power-to-weight ratio.

The YZ250 is ready to race out of the crate, complete with an aluminum handlebar, titanium foot pegs, gripper seat, and Excel® rims.

Ultra lightweight means nimble handling with less fatigue.

New for 2015:

All-new modern, aggressive styling for 2015.

The latest-generation KYB® Speed-Sensitive fork, just like the 4-stroke machines, has been added and provides industry-leading performance.

A clutch lever position adjuster is adopted to allow adjustments based on rider preferences and accommodates differing hand sizes.

The latest Dunlop MX52® tires are used for the best off-road traction, performance reliability.

Engine:

249cc liquid-cooled reed-valve-inducted two-stroke engine is lightweight, compact, and features an incredibly wide, hard-hitting powerband.

Patented YPVS power-valve system combines crisp, hard-hitting, bottom-end acceleration with strong midrange and eye-opening top-end.

38mm Keihin® PWK carburetor with power jet and throttle position sensor (TPS) provides precise fuel/air mixing and extra-crisp throttle response throughout the powerband.

Special-design carbon fiber reed-valve petals improve throttle response and engine performance across the entire rpm range

Smooth-shifting, five-speed, close-ratio transmission with heavy-duty, multiplate clutch.

Primary kickstarter ensures smooth, easy starting action and reduced weight.

Large-capacity radiator features a ten-row core with four louvers for maximum cooling efficiency.

Digital CDI ignition system delivers precise spark for faster, stronger response anywhere in the powerband.

Trick, works-style clutch lever features race-spec barrel adjuster for on the fly adjustability.

Chassis/Suspension:

YZ250F-style front-brake caliper and wave-style front and rear discs minimize unsprung weight and provide excellent stopping power.

The KYB® 48mm forks feature the Speed-Sensitive System that uses piston speed to control damping force for super-precise handling and a smooth ride.

A carefully engineered, advanced aluminum frame and swingarm give the YZ250 the best handling in the 250 class.

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

Rear, fully adjustable KYB® shock features a steel shock spring and reduced-friction Kashima coating of internals. 12.4 inches of travel, separate adjusters for high- and low-speed compression damping, and a full lock oil rebound system for increased comfort all add up to fantastic rear wheel control and a sweet ride.

Lightweight 21-inch front and 19-inch rear Excel® rims provide exceptional durability and help reduce unsprung weight for optimal suspension, performance, and handling.

Tapered rear wheel spacers ease sliding the rear wheel into place for quicker tire changes.

Premium Dunlop® knobbies offer race-spec traction and wear.

Additional Features:

Wide-diameter fuel tank cap ensures easier usage, while larger tank opening means faster, hassle-free refueling.

Special-design “gripper” type seat and fuel tank aluminum handlebars in an adjustable top clamp create greater freedom of movement and more comfortable ergonomics for riders.

Wide, cleated, folding foot pegs are lightweight and provide excellent comfort, grip and ground clearance.

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The Yamaha YZ85 is one of the most popular motorcycles in the world, and the bike continues its legacy with the same restyling features as the full-size premix burners.

All-new aggressive styling for 2015 with a new front fender, number plate, radiator shroud and side number plates.

Clutch lever reach adjuster to accommodate smaller hands for younger riders.

Liquid-cooled, 85cc crankcase reed-valve-inducted six-speed is light, compact and designed to deliver hard-hitting, moto-winning power throughout the rpm range.

Smooth-shifting, six-speed close-ratio transmission with heavy-duty, multiplate clutch delivers maximum hookup for outstanding acceleration and corner-exiting power.

Ultra-rigid, single-backbone, semi-double-cradle frame is lightweight and strong for sharp handling.

Fully adjustable suspension allows a broad adjustment range to suit everybody from rank novice to mini expert.

New for 2015:

Enhanced styling for a new front fender, front number plate, radiator shroud and side number plates. New coloring on the triple clamps and handlebars mimics the styling of the big YZs.

Improved air intake efficiency as well as intake/exhaust port timing has been revised for improved performance.

Clutch lever reach adjuster added to accommodate rider preferences and varying hand sizes.

New seat cover color and sharp new graphics.< Engine:

85cc liquid-cooled, crankcase reed-valve-inducted, two-stroke engine inhales through a 28mm Keihin® flat-slide carburetor; seamless throttle response across the powerband is the result.

Involute spline set-up in clutch means smoother shifting under power with great durability at competition-level usage

Two-piece clutch cover provides easy access during maintenance.

Lightweight radiator has large cores and louvers, and the water pump features a cast aluminum (vs. resin) impeller for maximum cooling efficiency.

Lightweight exhaust system design helps create a broader powerband with stronger low-end punch.

Airbox design ensures greater air cleaning performance and easier maintenance.

Chassis/Suspension:

Rear subframe is removable to allow easy maintenance.

Lightweight 36mm KYB® inverted cartridge fork features 10.8 inches of travel with compression and rebound damping adjustability, and low-friction outer tubes and internals.

Rear suspension features fully adjustable Kayaba® link-type shock with 11.1 inches of travel and race-tested compression damping valving.

220mm front disc and 190mm rear disc brakes with stainless steel rotors deliver strong, precise stopping power.

Lightweight 17-inch front and 14-inch rear rims are durable and reduce unsprung weight for optimal suspension performance.

Dunlop® knobbies provide great traction on a variety of tracks and terrain.

Additional Features:

Wide handlebar and flat fuel tank, radiator shrouds, side panels and rear fender provide rider with leverage and freedom of movement and weight transfer.

Wide foot pegs provide superb comfort and grip.

Separate clutch cover with transmission oil filler opening makes for easy maintenance.

Fuel tank cap is wider for easier usage, and large tank opening ensures fast, hassle-free refueling.

Repackable exhaust silencer.

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