|| Key Features:
- For 2007, the bike that started the four-stroke revolution benefits from significant chassis and engine refinements that ensure the five-titanium-valved YZ450F remains at the head of the open-class pack.
- Modifications to the light and strong aluminum frame and suspension mean light, precise, confident handling at any speed.
- Five-speed gearbox provides maximum flexibility and the right gear for a wide range of riding environments.
- Ready to race straight out of the crate - with a ProTaper aluminum handlebar in adjustable clamps, titanium shock spring, ti footpegs, gripper seat, etc.
New for 2007:
- 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.
- Increasing the length of the rear shock by 1.5mm further sharpens handling. Replacing steel damping adjusters with aluminum ones removes even more weight from the four-way adjustable, titanium-sprung rear suspension unit.
- A more rigid clutch pressure plate helps put power to the ground and dissipates heat more efficiently, especially during partial-clutch operation. Shorter lever stroke with 12-percent reduced effort means instant response.
- New, titanium exhaust pipe fattens low- and mid-range power while simultaneously adhering to 2007 AMA noise regulations.
- This year's ProTaper aluminum handlebar bend raises the grips 8mm for an expanded cockpit. Forged bar clamps reduce weight for superior handling.
- 449cc five-valve DOHC liquid-cooled engine is super-powerful yet tractable.
- 39mm Keihin FCR flat-slide carburetor with throttle position sensor (TPS) and leak jet delivers precise fuel/air mixture and instant throttle response.
- Revised CDI ignition keeps that amazingly broad and deep powerband hard-hitting, yet controllable.
- Lightweight, titanium valves and load-reduced springs minimize reciprocating mass for fast-revving, hard-hitting power delivery across the rev range.
- Additional weight-saving engine features include: small-design cam chain tensioner and oil pump, aluminum oil hose, all-titanium exhaust header, flange, bracket and heat shield and light CDI ignition unit.
- Primary kickstarting with automatic decompression and convenient handlebar-mounted hot start lever ensures easy restarts.
- Kick pinion gear is separate from the primary driven gear for smoother clutch engagement.
- Large-capacity radiator is reinforced for greater strength.
- Aluminum frame uses a mix of alloy casting, forgings and extrusions to produce a tuned-flex frame that makes the YZ the finest handling motocross bike ever.
- 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 Kashina-coated internals reduces friction for fantastic compliance and great handling.
- More weight savings come via two-piece (part aluminum, part plastic) engine protector plates and thin-walled engine guard construction.
- Removable aluminum rear subframe constructed of square-section 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 21-inch front and 19-inch rear Excel rims are exceptionally durable and reduce unsprung weight.
- “Gripper” style seat cover gives excellent feel and control, and the seat is lighter for 2007.
- Wide, cleated, folding titanium footpegs are light, strong, and provide excellent comfort, grip and ground clearance.
- Works-style clutch lever features oversize barrel adjuster for easy, on-the-fly adjustability of lever/cable play.
- Cleated rear brake lever and folding shift lever tip offer superb grip and excellent durability.
- Repackable exhaust silencer.
- Durable, comfortable handlebar grips.
- Stainless steel clutch cable for longer life.