| MODEL | YAMAHA WR 450F 2011 - 2012 |
| Year | 2011 - 2012 |
| Engine Type | Four stroke, single cylinder, DOHC, 5 valves |
| Displacement / Capacity | 449 cc / 27.4 cu in |
| Bore X Stroke | 95 x 63.4 mm |
| Compression Ratio | 12.3:1 |
| Cooling System | Liquid cooled |
| Max Power | 42.3 kW / 58 hp @ 9000 rpm |
| Max Torque | 49 Nm / 5.0 kgf-m / 36.2 lb-ft @ 7500 rpm |
| Ignition | CDI |
| Induction | 39 mm Keihin FCR flat-slide carburettor with throttle position sensor (per specs page); fuel injection per description |
| Start System | Electric and kick |
| TRANSMISSION SPECS | |
| Lubrication | Dry sump, 1.2 L oil |
| Gear Box | 5 speed, constant mesh |
| Clutch | Wet, multi-disc |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Aluminium bilateral beam |
| Front Suspension | 48 mm inverted telescopic fork, 300 mm / 11.8 in travel |
| Rear Suspension | Swingarm with link, monoshock, 305 mm / 12.0 in travel |
| Front Brakes | Hydraulic single 250 mm disc, 4-piston caliper |
| Rear Brakes | Single 245 mm disc, 2-piston caliper |
| DIMENSION SPECS | |
| Overall Length | 2315 mm / 91.1 in |
| Overall Width | 825 mm / 32.5 in |
| Overall Height | 1275 mm / 50.2 in |
| Seat Height | 960 mm / 37.8 in |
| Wheelbase | 1475 mm / 58.1 in |
| Ground Clearance | 335 mm / 13.2 in |
| Dry Weight | — |
| Wet Weight | 122 kg / 268 lbs |
| WHEEL SPECS | |
| Front Tyre | 80/100-21 51P |
| Rear Tyre | 120/90-18 65P |
| FUEL SYSTEM | |
| Fuel Capacity | 7.2 Litres / 1.9 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The fifth-generation WR450F introduced fuel injection with a Power Tuner for adjusting the mapping, and a new aluminium bilateral-beam frame derived from the YZ250F chassis with the engine rotated for better mass centralisation. Suspension was reworked for enduro use. Testers praised the tractable engine and suspension but felt it was a little heavy.
