The Yamaha Grizzly is a large utility all-terrain vehicle manufactured by the Yamaha Motor Company. It has a 595cc four-stroke engine from the XT600. Yamaha replaced the Grizzly 600 with the new Grizzly 660 using a larger engine that is 660cc derived from the Raptor 660 with a five-valve cylinder head.
Beyond the engine, the biggest differences between the Grizzly 600 (offered in the US from 1998 to 2001) and the Grizzly 660 (introduced in 2002), is the rear suspension. The older Grizzly has a rigid rear axle with a single shock. The newer Grizzly has independent rear suspension with dual shocks. This is reported to have significantly improved the handling characteristics of the newer model. The Grizzly includes push button 4 wheel drive and diff lock.
In 2007 Yamaha came out with the Grizzly 700 that provides fuel injection and optional EPS (electric power steering), that has been getting great reviews. Also, the 700 uses "gull wing" bent axle on the rear, allowing for a shorter frame, and reduced weight.