| Year | 2005 |
| Bore x Stroke | 100 x 82.6 mm |
| Capacity | 644 cc / 39.35 cu-in |
| Clutch | Heavy duty multi-plate clutch |
| Compression Ratio | 8.3:1 |
| Cooling System | Air cooled |
| Dry Weight | 147 kg / 324 lbs |
| Engine | Four stroke, single cylinder SOHC, 4 valve |
| Final Drive | #520 O-ring-sealed chain; 15T/45T |
| Front Brakes | Single 240 mm disc 2 piston caliper |
| Front Suspension | 43 mm Showa forks, 16-way adjustable preload |
| Front Tyre | 80/100-21 |
| Front Wheel Travel | 294 mm / 11.6 in |
| Fuel Capacity | 10.6 Litres / 2.8 US gal |
| Gear Ratio | 1st 2.66 2nd 1.64 3rd 1.25 4th 1.00 5th .84 |
| Ground Clearance | 330 mm / 13.0 in |
| Ignition | Solid-state CDI |
| Induction | 40 mm diaphragm-type CV carburetor |
| Lubrication | Dry sump |
| Max Power | 43.6 hp / 32.1 kW @ 6000 rpm |
| Max Torque | 51.9 Nm / 5.3 kgf-m / 38.2 lb-ft @ 5000 rpm |
| Oil Capacity | 1.9 Litres |
| Rake | 27° |
| Rear Brakes | Single 240 mm disc 1 piston caliper |
| Rear Suspension | Pro-link Kayaba fully adjustable |
| Rear Tyre | 110/100-18 |
| Rear Wheel Travel | 280 mm / 11 in |
| Seat Height | 940 mm / 37 in |
| Starter | Electric |
| Trail | 102 mm / 4.0 in |
| Transmission | 5 Speed |
| Wet Weight | 158 kg / 348 lbs |
| Wheelbase | 1455 mm / 57.3 in |
