The 2009 Yamaha YFZ 450 displaces 449 cc

The 2009 Yamaha YFZ 450 displaces 449 cc. It's liquid-cooled with auxiliary fan. The cylinder bore is 3.74 inches, while the stroke is 2.49 inches. The compression ratio is high at 11.4:1, with fuel delivered through a Keihin 39 mm carburetor with a throttle position sensor. The ignition is electric. The ATV is driven with a five-speed transmission.
Chassis

The front suspension offers 9.1 inches of travel through a double wishbone independent system with rebound adjustability. In the rear is an aluminum swing arm and 10.6 inches of travel. Twin-piston, dual ventilated brakes are in the front with twin-piston ventilated discs in the rear.
Dimensions

The 372-lb. YFZ 450's wheelbase is 50.4 inches with an overall length measuring 72.4 inches. The chassis clears the ground by 4.5 inches and the seat is 31.9 inches high. The ATV sits on AT21X7-010 radials in the front and AT20X10-9 radials in the rear.