First Look: 2008 Yamaha YZ250F

You can click the following link to check out a gallery of photos of the 2008 Yamaha YZ250F.

Key Features:

• Ongoing refinement to chassis and engine produce an amazingly balanced, light-handling machine with performance that's accessible to all levels of riders.
• Five-titanium-valve engine with increased compression spins out even more torque and horsepower.
• A carefully tuned aluminum frame made up of forgings, weldings, castings and tubing means sharp, super-precise handling.
• Mass centralization provides fantastic overall balance and performance.
• A ProTaper aluminum handlebar in adjustable clamps, Excel rims and a titanium shock spring are just a few tricks up the YZ250F’s sleeve.

New for 2008:

• A redesigned piston bumps compression ratio from 12.5:1 to 13.5:1, further exploiting the inherent efficiency of the five-valve combustion chamber. Carburetion and ignition revisions complement the increased compression.
• Adjustment of gear backlash between clutch primary gears and balancer gears reduces mechanical noise.
• Changes to the clutch boss and primary driven gear improve clutch oiling for excellent durability.
• Matte black crankcase covers: light and cool-looking.
• Changes to the shape of the outer fork tubes and lower triple clamp, and revised fork internals, result in excellent handling, great damping and a smooth ride.
• Optimized linkage ratio provides a smoother ride and enhanced rear wheel traction.
• 55mm stainless steel footpegs replace 45mm ones for great grip and comfort, and a new brake pedal eases operation.
• Grippy new Bridgestone knobbies front and rear.

Engine:

• Liquid-cooled 250cc, five-titanium-valved, DOHC, four-stroke is powerful and highly tractable, with an rpm redline for competition-crushing pulling power.
• 37mm Keihin FCR flat-slide carburetor with throttle position sensor (TPS) ensures precise fuel/air mixing and lightning-quick throttle response.
• CDI ignition provides a hot, consistent spark across the powerband for right-now throttle response.
• Lightweight, titanium header pipe (with titanium heat shield) flows into an aluminum silencer for maximum power.
• Cylinder body and crankcase feature a large cutaway section to reduce pumping loss and increase midrange performance.
• Primary kickstarting (with automatic decompression and convenient handlebar-mounted hot start lever) ensures easy restarts.
• Slick, five-speed transmission with heavy-duty, multiplate clutch features an involute spline setup, ensuring smooth shifting and instant hookup under power.
• Magnesium cylinder head cover helps shave weight.
• Trick, works-style clutch lever features race-spec barrel adjuster for on-the-fly adjustability.

Chassis/Suspension:

• Extensively tested aluminum frame uses a mix of alloy castings, forgings and extrusions to produce a tuned-flex frame that makes the YZ250F the best-handling bike in its class.
• Speed-Sensitive System 48mm Kayaba fork places transfer control valves (TCV) above the fork springs, so that damping force is controlled by piston speed: Eliminating mid-stroke damping force changes provides a smoother, more precise ride.
• Titanium-sprung, four-way adjustable, rear shock with Kashima-coated internals reduces friction for fantastic compliance and great handling.
• Removable aluminum rear subframe is constructed of square-section tubing for light weight and easy maintenance.
• Lightweight front wheel hub for reduced unsprung weight and increased durability.
• Lightweight front and rear brake calipers with aluminum pistons and anti-bubble front master cylinder; new wave-style rotors reduce unsprung weight and deliver strong stopping power.
• Lightweight 21-inch front and 19-inch rear Excel rims are exceptionally durable and reduce unsprung weight.

 Additional Features:

• “Gripper” style seat cover offers excellent feel and control.
• ProTaper handlebar with durable, comfortable grips.