Upgrades for 2004 consist of a rigid 48mm fork with new settings for a smooth, compliant and progressive feel. New, titanium footpegs and gripper-style seat cover material improve the crucial interface between man and machine — and man, what a machine: 222 pounds of high-tensile steel-framed, loam-launching, terrain-following, thrill-seeking motocross machine.
Yamaha-exclusive five titanium valve head (three intake, two exhaust) reduces reciprocating mass and helps make 11,000 rpm a regularly recurring event.
Bringing a 95mm piston to life against 12.5:1 compression can be hard work; YZ450F’s genius auto-decompression system and hot start lever make it quite easy.
The YZ450F’s high-revving counterbalanced 449cc liquid-cooled five-titanium valved 39mm Keihin-carbureted single is pure moto winning magic.
And four speeds are plenty, given the YZ450F’s seismic spread of power — and a heavy-duty clutch that gets the power to the ground consistently.