TOP FEATURES
1. Innovative Engine Design
A liquid-cooled, DOHC 4-valve, fuel-injected engine with forward positioned downdraft intake delivers class leading engine power, updated for 2017 to further improve top-end power. This engine design allows for unmatched mass centralization, concentrating the motorcycle’s key components—engine, fuel tank and exhaust system—toward the center of the motorcycle achieving light and nimble handling performance.
2. Updated Transmission
New gear dogs, revised gear tooth designs and a host of smaller changes create a smoother overall transmission with improved shifting, as well as a stronger overall powertrain for improved durability.
3. Bilateral Beam Aluminum Frame
A Yamaha’s renowned bilateral beam aluminum frame features compact overall dimensions that balance minimal weight with the strength and rigidity needed for race-winning performance. This frame features a new forged section at the swingarm pivot, and engine mounting brackets for tuned responsiveness, handling and unmatched lightweight feeling.
4. Updated Suspension Settings
Industry-leading, fully adjustable KYB® spring-type fork with speed sensitive damping features revised valving for improved suspension feel and balance. The KYB® rear shock also features settings optimized for ideal damping characteristics.
5. GYTR® Power Tuner Ready
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, as well as monitor engine diagnostic codes.
FEATURES & BENEFITS
NEW FOR 2017:
New Cylinder Head and Intake System
The compact four-valve cylinder head features revised intake geometry for additional downdraft effect, matched to shorter intake funnel in the airbox, for improved top-end power. Inside the head, more aggressive camshaft profiles and valve springs boost output further, while larger valve seats ensure excellent sealing and reliability.
Stronger Connecting Rod and Crankcase
The entire die-cast crankcase features a new heat treating process to increase strength. Inside, a new nickel-chromoly steel connecting rod offers additional durability to handle the increased power output.
Updated Transmission
New gear dogs, revised gear tooth designs and a host of smaller changes create a smoother overall transmission with improved shifting, as well as a stronger overall powertrain for improved durability.
Updated Frame and Suspension
Revised engine mounts and a reshaped swingarm pivot section of the aluminum frame improve lateral rigidity, while 5mm lower footpegs help lower the rider’s center of gravity for improved machine balance and control, revised suspension settings front and rear to match the
chassis updates.
Simplified Servicing
Redesigned air cleaner cover helps prevent contact with the quick-release quarter-turn Dzus® air box fasteners and provides tool-less access to the air filter, positioned at the front of the bike to avoid roost from the rear wheel.
ENGINE
Innovative Engine Design
The liquid-cooled, DOHC 4-valve, fuel-injected engine features a forward-positioned straight downdraft intake, with a symmetrical intake and exhaust port layout and a compact, high compression combustion chamber, delivers outstanding engine character, with updates for 2017 designed to further improve top-end power.
Piston, Rod and Crankshaft Balance
A flat-top forged piston features a bridge-box design for additional strength with minimal weight. The piston, rings and DLC-coated piston pin, along with the offset cylinder configuration, all reduce friction loss and contribute to quick response. The engine’s reshaped intake ports, updated cam profiles, ECU, strengthened connecting rod and optimized crank and counterbalancer all work together to give the YZ250F a user-friendly engine character with potent high-rpm power.
Advanced ECU and Fuel Injection
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. For 2017, new settings provide a smoother feeling as the rider reaches the rev limiter.
Wraparound Rear Positioned Exhaust Layout
An innovative exhaust pipe design improves mass centralization and 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. An updated midpipe profile improves exhaust gas flow for enhanced mid- and top-end power.
Updated Transmission
The transmission gears, dogs and shift mechanisms are updated for 2017 to smooth gear changes and improve durability under the heavy demands of motocross racing.
GYTR Power Tuner Ready 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, as well as monitor engine diagnostic codes.
CHASSIS/SUSPENSION
Bilateral Beam Aluminum Frame
A Yamaha's renowned bilateral beam aluminum frame features compact overall dimensions that balance minimal weight with the strength and rigidity needed for race-winning performance. This frame features a reshaped swingarm pivot section, updated engine mounting brackets turned for stability, responsiveness and sharp cornering.
Mass-Centralization
The engine, aluminum muffler and fuel tank are positioned closer to the machine's center of gravity. This layout contributes to centralized mass for a lightweight handling feeling on the track. The wide 55mm footpegs have been lowered 5mm to help lower the rider's center of gravity for improved machine balance and control and increased rider comfort.
270mm Front Brake
A large 270mm front brake disc is the same system fitted to the YZ450F™, and uses an aggressive pad material for exceptional stopping power and braking control. Out back, a new, more heat resistant rear rotor boots brake durability.
Updated Suspension Settings
Industry-leading, fully adjustable KYB® spring-type fork with speed sensitive damping features revised valving for improved suspension feel and balance. The linkage type rear suspension features a KYB® rear shock also features settings optimized for ideal damping characteristics.
ADDITIONAL FEATURES
Embedded Graphics
Yamaha’s unique embedded graphics are built into the bodywork for extended durability, resisting both peeling and damage, with new styling for 2017.
Adjustable Handlebar Mounts
The 4-position adjustable handlebar mounts are rubber mounted to improve comfort and reduce handlebar vibration.
Race Winning Details
The YZ450F includes top-spec details, including 1-1/8” aluminum tapered handlebars, wide 55mm footpegs, a quick-adjust clutch perch, stylish black rims and gold chain.
SPECIFICATIONS
Engine Type: 250cc liquid-cooled DOHC 4-stroke; 4 titanium valves
Bore x Stroke: 77.0mm × 53.6mm
Compression Ratio: 13.5:1
Fuel Delivery: Keihin® fuel injection, 44mm
Ignition: TCI: Transistor Controlled Ignition
Transmission: Constant-mesh 5-speed; multiplate wet clutch
Final Drive: Chain
Suspension / Front: KYB® Speed-Sensitive System inverted fork; fully adjustable, 12.2 in travel
Suspension / Rear: KYB® single shock; fully adjustable, 12.4 in travel
Brakes / Front: Hydraulic disc, 270mm
Brakes / Rear: Hydraulic disc, 245mm
Tires / Front: 80/100-21 Bridgestone® M403A
Tires / Rear: 100/90-19 Bridgestone® M404
L x W x H: 85.2 in x 32.5 in x 50.4 in
Seat Height: 38.0 in
Wheelbase: 58.1 in
Rake (Caster Angle): 27.1°
Trail: 4.6 in
Ground Clearance: 12.8 in
Fuel Capacity: 2.0 gal
Wet Weight***: 231 lb
Warranty: 30 Day (Limited Factory Warranty)
Color: Team Yamaha Blue; White/Red
MSRP: $7,699
Manufacturer's Suggested Retail Price (MSRP) shown. Does not include tax, title, prep or destination charges. Actual prices set by dealer.
*** Wet weight includes the vehicle with all standard equipment and all fluids, including oil, coolant (as applicable) and a full tank of fuel. It does not include the weight of options or accessories. Wet weight is useful in making real-world comparisons with other models.
Specifications subject to change without notice. This document contains many of Yamaha's valuable trademarks. It may also contain trademarks belonging to other companies. Any references to other companies or their products are for identification purposes only, and are not intended to be an endorsement. © 2016 Yamaha Motor Corporation, U.S.A. All rights reserved.
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