Yamaha YZ450F

The Yamaha YZ450F is a four-stroke racing motocross bike built by Yamaha Motor Corporation, the successor to the YZ426F that was discontinued in 2003. Cycle World and Dirt Rider credit it with starting the four-stroke dirt bike revolution, and its 2006 version and the YZ250F were the first production motorcycles with titanium suspension springs. The line traces back to the YZ400F of 1998, which Doug Henry rode to the first AMA National Motocross title won on a four-stroke. It became the YZ450F in 2003 with a 449 cc engine to fit the new AMA displacement limit, was redesigned in 2006, got fuel injection with an all-new 2010 model and, from 2018, electric start and the Yamaha Power Tuner smartphone app. The 2023 model, the eighth generation, is lighter, adds a dry-sump engine and has launch and traction control. The WR450F is its enduro version.