Significantly updated last year, the 449cc engine features a single overhead camshaft operating four valves via lighter rocker arms instead of the twin-cam setups on the 450 SX and XC. Tamer in peak output than its revvy cousins, the XC-W provides smooth, tractable power that is perfect for tight technical riding, yet strong enough to make short work of sand washes or steep, loose inclines. The Keihin MX FCR 39 carburetor, in conjunction with the new cam, provides consistent throttle response. A revised decompression system and updated jetting ensure better starting, especially when cold. A kick-start backup is retained, unlike with the five-speed XC line.