25 THINGS YOU NEED TO KNOW ABOUT THE 2010 YAMAHA YZ450F:

In its third year theYZ450F’s new rearward-slanted cylinder is still revolutionary idea that was designed for mass centralization (concentrating inertial mass toward the center of the machine). This bold design idea also swaps traditional intake and exhaust positions, putting  airbox and throttle body out front. This contributes to mass centralization,while also achieving a straight intake tract for superb combustion efficiency that delivers more power.

1. The cylinder is offset so the connecting rod is vertical at the moment of greatest combustion force, minimizing piston friction against the cylinder wall that could rob power. That means quicker response.

2. The four-titanium valve cylinder head is matched to a fuel injection system developed specifically for the YZ450F. Instantly adapts to changing air/fuel mixtures depending on altitude and temperature, for an engine that delivers no matter what conditions.

3. The aluminum Bilateral Beam frame is crafted from a carefully chosen combination of forged and extruded aluminum, 16 components in all, for the right rigidity balance and light weight.

4. The accessory GYTR Power Tuner lets bike tuners adjust air/fuel mixture and ignition timing maps to match engine performance characteristics to the rider and track conditions. Iis the easiest remapping tool in the sport.

5. The rearward-slanted engine allowed engineers to design straight intake and exhaust ports, creating the most direct path for air flow into the fuel-injected engine.

6. The YZ450F uses a battery-less fuel injection system with a 12-hole injector for superb fuel atomization. The 44mm Keihin throttle body is designed for easy starting, with an integrated cold start and idle speed adjustment knob. Yamaha FI provides optimal air/fuel mixtures in all altitudes and wide range of temperatures for outstanding throttle response.

7. The 14 volt / 110W high output generator powers the battery-less fuel injection system.

8. Four-titanium valve cylinder head with a “pent-roof” design combustion chamber provides excellent combustion efficiency and unequaled power output.

9. Intake and exhaust camshaft profile changes to increase valve working angle and valve lift for most excellent performance at all rpm.

10. The bore is 97.0mm, while the stroke is 60.8mm. The compression is 12.5:1.

11. The air filter case is unique for a Japanese bike in that it is in the front of the gas tank, but ATK did this decades ago and Husaberg and Husqvarna have variations on the same idea.

12. In order to get the correct tuned length from the rear exhaust port, Yamaha had to develop the “tornado” exhaust header. It has a built-in resonance chamber and a muffler that is 150mm-longer than the 2009 YZ450F muffler.

13. Clutch and transmission components have been thoughtfully revamped to give the rider great shifting feel.

14. New skid plate is constructed from tough polypropylene for great protection and low weight.

15. The swingarm and rear shock are redesigned, with the shock mounted along the central axis of the frame, taking advantage of the space no longer needed for the front-mounted airbox. This optimized combination delivers exceptionally linear performance for excellent bump absorption and awesome cornering ability.

16. The KYB Speed Sensitive front fork has 10mm longer stroke for excellent feel and shock absorption.

19. KYB rear shock with large capacity piggyback reservoir and 50mm piston for more consistent damping control.

20. New fuel tank is positioned underneath the seat, contributing to the centralized mass. The seat is long and flat for to allow free rider movement.

22. New rear sprocket shape has a trick appearance and is light weight.

23. The triple clamps are redesigned, with a change in offset from 25 to 22 mm for unequaled cornering performance. The Pro Taper bars are four-way adjustable to accommodate a wide range of riders.

24. The front and rear fenders, along with the number plate, side cover and front fork protector have been redesigned for an aggressive look. Less plastic is used to expose and enhance the lightweight aluminum frame.

25. Fuel pump is small and lightweight, as is the compact transistor ignition unit.