Fresh Dirt On '03 Mxers

FRESH DIRT ON '03 MXERS

Jimmy Lewis

WHAT TO EXPECT FROM the forthcoming crop of Japanese twoand four-stroke motocrossers? Here’s a sneak peek at some of the changes:

Aside from the all-new CR85R, Honda’s lineup appears identical, but extensive internal engine updates were made to all three full-size CRs. The CR125R is said to be a real rocketship, and even the brutally fast CR250R got a power boost.

There’s more motor for the fourstroke CRF450R, too, via an altered camshaft and exhaust system. Revisions to the two larger bikes’ chassis include a new shock linkage that puts more weight on the front end and provides even better suspension compliance. The rumored CRF250R is still just that, though reports of strange - sounding, high-rpm four-strokes are being bandied about. With some of Honda’s engineers released from MotoGP duty, full of ideas, could an Interceptor-inspired f VTEC valvetrain be far behind?

Kawasaki has finally addressed the need to upgrade the longrunning KX125 with an all-new chassis styling, plus a clean-sheet engine. The KX250’s powerplant, however, gets updates only; we suspect Team Green is preparing an all-new powerplant for ’04. Both bikes have lighter, more rigid perimeterstyle frames that are nearly identical, save for the lower cradle. Close inspection of the new frame reveals there may be room for a slightly larger motor. Will there be a four-stroke KX in the future? We believe so.

Suzuki isn’t talking, but photos of its works RM250 are. See the all-new engine? More compactness and big power increases are expected. And what about Yamaha? Well, say goodbye to the YZ426F, and hello to the YZ450F! Oddly enough, the increase in displacement to 449cc isn’t as big news as is the drop in weight. Reportedly, the 450 weighs at least 10 pounds less than its predecessor, the target being to scale 1 pound lighter than the Honda CRF. The engine is still a dry-sump design, but with less oil capacity and hose complexity. More motocross-focused, the 450 has a four-speed transmission, all-new plastic, a flatter seat and gas tank, a new airbox and a revised frame with additional strengthening via high-tensile steel gusseting. Automatic decompression will ease the starting drill, while the hotstart button is now activated via a handlebar-mounted lever. Close inspection reveals new clutchcable routing and bosses on the brand-new cases that will act as mounting for an electric-starter

WR450F. The little brother YZ250F sees most of the changes, too. The two-stroke YZs, meanwhile, have a host of internal updates, with the most visible difference being an integrated rear-brake master-cylinder reservoir.

All around, it looks like another banner year for the motocross market.