2013 Yamaha YZ450F, 2013 Yamaha® YZ®450F THE REVOLUTIONARY YZ®450F! A slanted, rearward facing cylinder with reversed intake ports all housed in a Bilateral Beam provides unmatched mass centralization, amazing balance and is one of the lightest henadling bikes on the track. combine this with Yamahas legendary engine durability and high-quality components and you have the bike of choice for winning racers. Features YZ®450F s still revolutionary design advancements include its rearward-slanted cylinder that achieves unmatched mass centralization, concentrating inertial mass toward the center of the machine. This bold design swaps traditional intake and exhaust positions, putting the lightweight airbox and throttle body out front. This contributes to mass centralization for nimble handling while also achieving a straight intake tract for superb combustion efficiency that delivers more power. 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. The 4-titanium valve cylinder head is matched to a newly recalibrated fuel injection system that provides superb low-to-mid-rpm power feeling. Instantly adapts to changing air/fuel mixtures depending on altitude and temperature, for an engine that delivers no matter what conditions. The aluminum double S bend Bilateral Beam frame provides a superb rigidity balance and, with new front and rear suspension settings, provides unmatched lightweight handling and cornering. Combined with the mass centralization provided by the engine, YZ®450F for 2013 is a formidable, well-tuned package. 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.