Features |
 |
|
|
|
Liquid-cooled, 249cc, five-titanium-valved, DOHC, four-stroke is powerful and highly tractable, with a 13,500-rpm redline for broad, 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. |
|
Light, dished forged piston reduces reciprocal mass and friction for fast revving and excellent durability. |
|
Lightweight titanium header pipe (with titanium heat shield) flows into a new aluminum silencer for maximum power. |
|
Cylinder body and crankcase feature a large cut-away section to reduce pumping loss and increase mid-range performance. |
|
Primary kickstarting (with automatic decompression and convenient handlebar-mounted hot start lever) ensures easy restarts, and a new kickstart lever provides great leverage. |
|
Slick, five-speed transmission with heavy-duty, multiplate clutch features an involute spline set-up, ensuring smooth shifting and instant hook-up under power. |
|
Magnesium cylinder head cover helps shave weight. |
|
Trick, works-style clutch lever features race-spec barrel adjuster for on-the-fly adjustability. |
|
The dry sump oil tank now has an internal partition for better oil flow, and revised oil lines reduce weight. |
|
|
|
|
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 Kashimacoated internals reduces friction for fantastic compliance and great handling. |
|
Removable aluminum rear subframe constructed of squaresection tubing for light weight and easy maintenance?lighter fasteners for 2007 enhance weight distribution and handling. |
|
Lightweight front wheel hub for reduced unsprung weight and increased durability. |
|
Premium Dunlop knobbies provide unbeatable, competition-spec traction and great wear. |
|
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 with
progressive feel. |
|
Lightweight 21-inch front and 19-inch rear Excel rims are exceptionally durable and reduce unsprung weight. |
|
|
|
|
?Gripper? style seat cover offers excellent feel and control. |
|
Wide, cleated, folding titanium footpegs are lightweight and provide excellent comfort, grip and ground clearance. |
|
Cleated rear brake lever and folding shift lever tip offer superb grip and excellent durability. |
|
Durable, comfortable handlebar grips. |
|
Stainless steel clutch cable for longer life. |
|
|
|
|
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 spins out amazing torque and horsepower all the way to 13,500 rpm. |
|
A carefully tuned aluminum frame made up of forgings, weldings, castings and tubing means sharp, super-precise handling. |
|
Increased mass centralization and 2.5-pound weight reduction provides fantastic overall balance
and performance. |
|
A ProTaper aluminum handlebar in adjustable clamps, Excel rims, titanium footpegs and shock spring are just a few tricks up the YZ250F?s sleeve. |
|
Carburetion, ignition and other modifications provide more top-end performance and over-rev ability. |
|
The engine mounting angle has been changed; rotating the cylinder head rearward changes the balance of the machine for compactness and sharp handling. Smaller engine mounting bolts and other things add up to 2.5 pounds less weight. |
|
Moving the steering head 3mm rearward makes the bike supernimble turning into tight corners, and carves tight lines. |
|
Replacing the upper cast triple clamp with a light and strong forging, slightly reducing steering head rigidity, and the use of lighter outer fork tubes, lighter wheel rims and light wave-type brake rotors add up to super-accurate, super-responsive steering. A new front axle bracket saves weight. |
|
A lighter front brake caliper and master cylinder with smaller pistons saves weight; a new front brake lever gives excellent feel. The result is outstanding braking power and less unprung
front-end weight. |
|
Increasing the length of the rear shock by 1.5mm further sharpens handling. Replacing steel damping adjusters with aluminum ones removes more weight from the four-way adjustable, titaniumsprung rear suspension unit. Adopting YZ250-style rear linkage saves weight and increases strength. |
|
Other mass-centralization measures include a lighter rear axle and adjusters, and replacing more than 50 fasteners throughout the
bike with lighter ones. |
|
New exhaust pipe works with engine changes to boost top-end response while adhering to 2007 AMA noise regulations. |
|
This year?s ProTaper aluminum handlebar bend raises the grips a bit for an expanded cockpit. Forged bar clamps reduce weight for superior handling. |
|
|
|