TWO-STROKE TOUR DE FORCE. So, just how good a machine is this? Well, roll out its ample collection of "Bike of the Year" awards and 125 Supercross titles, for starters. Then put an exclamation point on it with this bit of news: The 2003 YZ125 is poised to raise the bar to even newer heights. Commence in the engine room, where broader, more usable power and crisper throttle response is on tap across the rev range, thanks to reshaped exhaust porting and combustion chamber volume, a modified YPVS power valve, all-new reed-valve petals and revamped carb settings. And, like its YZ250 sibling, lighter, more responsive chassis performance comes via a lighter-weight swingarm and stiffer frame, revised fork and shock internals, light Excel rims, and lighter, stronger brakes.