New for the 2005 Yamaha YZ450F:

• Faster and smoother than ever.
• Redesigned combustion chamber, piston, intake ports, carburetor jetting and airbox for improved combustion efficiency, resulting in smoother more controlled power delivery.
• Redesigned CDI unit for smoother more controlled power delivery.
• Primary drive gear ratio has been changed from 2.82 to 2.65:1, clutch spring rate is reduced 6 percent for lighter lever pull, and a new shift mechanism provides more positive shifting.
• All-new fork with TCV (transfer control valve) for stable damping, improved mid- to full-stroke performance and better rider feedback.
• New, aluminum Renthal handlebar is 90 grams lighter and more durable.
• Revised triple clamps for even better handling.
• Shorter, re-routed front brake hose for increased brake feel and easier bleeding.
• Stronger swingarm with stronger new linkage for better performance.
• Rear shock has a new, full-rebound oil lock circuit for a smoother ride.
• New-design rear sprocket and chain guide reduces wear, chain wobble, and noise for more efficient power transfer.
• Rear brake bracket is 35 grams lighter, and designed for easier rear wheel installation.
• New front fork protectors are larger for better coverage.