You can click the following link to check out a gallery of photos of the 2008 Yamaha YZ450F. |
Key Features:
- The bike that started the four-stroke revolution benefits from chassis and engine refinements that ensure the five-titanium-valved YZ450F remains at the head of the open-class pack.
- Subtle modifications to the aluminum frame and suspension mean light, precise, confident handling at any speed.
- New head and exhaust design delivers stronger low- to midrange power without sacrificing top end power.
- Ready to race straight out of the crate—with a ProTaper aluminum handlebar in adjustable clamps, titanium shock spring, gripper seat, Excel rims, etc.
- Five-speed gearbox provides maximum flexibility and the right gear for a wide range of riding environments.
New for 2008:
- Revised intake port shapes, and revised intake and exhaust cam profiles increase combustion efficiency for improved torque and throttle response in the low- to mid-rpm range.
- Micron-level adjustment of piston external diameter minimizes piston-to-cylinder clearance for reduced vibration and mechanical noise.
- Adjustment of gear backlash between clutch primary gears and balancer gears achieves further mechanical noise reduction.
- A new, larger-diameter titanium exhaust header with revised taper characteristics enhances exhaust efficiency.
- First “punched cone” muffler ever on a production bike allows 35 percent length reduction and 270-gram weight reduction while meeting AMA noise regulations.
- Matte black crankcase covers: light, strong and cool-looking.
- Steering head pipe and steering stem are 5mm shorter; lower forged triple steering clamp is lighter—for enhanced handling feel. Swingarm pivot stiffness is revised to complement front-end changes and further lighten and improve steering/handling.
- Changes to the shape of the outer fork tubes and revised internals result in improved damping and a smoother ride.
- Optimized linkage ratio provides a smoother ride and enhanced rear wheel traction.
- New, YZ250F-style, front-brake caliper (-220 grams) and a lighter disc remove unsprung weight and provide excellent stopping power. A new axle and collar remove additional weight.
- A 120/80-19 rear Dunlop D756 knobby replaces the 110/90-19 for even more traction. A D742FA replaces the D739FAL front tire.
- Wider footpegs provide excellent boot traction and rider comfort.
Engine:
- 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.
- Lightweight titanium valves and load-reduced springs minimize reciprocating mass for fast-revving, hard-hitting power delivery across the rev range.
- Primary kickstarting with automatic decompression and convenient, handlebar-mounted hot start lever ensures easy restarts.
- Large-capacity radiator is reinforced for greater strength.
Chassis/Suspension:
- Extensively tested aluminum frame uses a mix of alloy castings, 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 Kashima-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.
- 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; wave-style rotors reduce unsprung weight and deliver strong stopping power.
Additional Features:
- “Gripper” style seat cover gives excellent feel and control.
- ProTaper aluminum handlebar for strength and performance.
- Works-style clutch lever features oversize barrel adjuster for easy, on-the-fly adjustability of lever/cable play.
- Repackable exhaust silencer.
- Durable, comfortable handlebar grips.
MSRP* | $7,099 (Team Yamaha Blue/White) $7,199 (White/Red) |
Engine |
|
Type | 449cc liquid-cooled DOHC 4-stroke; 5 titanium valves |
Bore x Stroke | 95.0 x 63.4mm |
Compression Ratio | 12.3:1 |
Carburetion | FCR-MX39 x 1 |
Ignition | CDI |
Transmission | Constant-mesh 5-speed; multiplate wet clutch |
Final Drive | Chain Drive |
Chassis |
|
Suspension/Front | Speed-Sensitive System inverted fork; fully adjustable, 11.8-in travel |
Suspension/Rear | Fully adjustable single shock; 12.3-in travel |
Brakes/Front | Hydraulic single disc brake, 250mm |
Brakes/Rear | Hydraulic single disc brake, 245mm |
Tires/Front | 80/100-21-51M |
Tires/Rear | 120/80-19-62M |
Dimensions |
|
Length | 86.4 in |
Width | 32.5 in |
Height | 51.4 in |
Seat Height | 38.9 in |
Wheelbase | 58.8 in |
Ground Clearance | 14.7 in |
Dry Weight | 219 lb |
Fuel Capacity | 1.8 gal |
Other |
|
Warranty | 30 Day (Limited Factory Warranty) |