For 2000, Yamaha's engineering team wanted to improve the overall power, handling, suspension and ergonomics. Cylinder modifications, shifting improvements, frame layout design and suspension modifications were addressed.

Perhaps the most impressive feature of the YZ125 is the motor; for 2000, Yamaha squeezed out even more power. Changes to the cylinder and Yamaha's Power Valve System increase the low to mid range punch. A reshaped exhaust port and valve width increase from 27.3mm to 29.3mm enhances the overall power output.

For harnessing the power under increased loads, engineers beefed up the transmission, improving the gear-shifting operation. The clutch pressure plate, section and shape, was modified for a "its-never-too-light" feeling. To further enhance the feel, the drive axle now features an involute spline, replacing last year's hexagonal spline. The stopper lever assembly was upgraded from a roller plate to a bearing improving the feeling and durability. Another notable change is the incorporation of Yamaha's new "works-style" adjustable clutch lever and perch. This is the same setup factory riders Jeremy McGrath, Jimmy Button, John Dowd and Doug Henry have been using on the Supercross and National circuit all year.

The 125 benefits from an improved chassis. It has a fully detachable aluminum subframe that is 10mm lower in the rear for a flatter seating position, but less weight than the previous steel construction. Overall weight loss is also achieved via a thinner, yet stiffer, HT-780 high tensile steel tubing on the main tube.

The suspension of the YZ125 is upgraded at both ends. The forks feature new anti-stiction dust seals, outer tubes with low friction internals and a lightweight aluminum piston rod for smoother suspension performance. The rear shock benefits from an aluminum bearing in place of the '99 steel item, and completely new adjustable compression damping adjuster allowing the rider to dial in his suspension to meet the ever changing track conditions on race day.

Yamaha's finishing touches include a rear suspension design that results in less unsprung weight. Excel rims grace the YZ125 in the front and rear (as with the YZ250 and YZ426F), providing superb strength. Yamaha's lightweight hub, aluminum spoke nipples and all-new Dunlop 739FAs complete the rear setup.

The 2000 YZ125 is available in Team Yamaha Blue/White and will have a manufacturer's suggested retail price of $4,799.