| MODEL | YAMAHA WR 426F 2001 - 2002 |
| Year | 2001 - 2002 |
| Engine Type | Four stroke, single cylinder, DOHC, 5 valve |
| Displacement / Capacity | 426 cc / 26.0 cu in |
| Bore X Stroke | 95 x 60.1 mm |
| Compression Ratio | 12.5:1 |
| Cooling System | Liquid cooled |
| Max Power | 42.4 kW / 58.1 hp @ 9000 rpm |
| Max Torque | 49 Nm @ 7000 rpm |
| Ignition | Digital CDI |
| Induction | 39 mm Keihin FCR39H carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 5 speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | 46 mm Kayaba inverted telescopic fork, compression and rebound damping adjustable, 300 mm / 11.8 in travel |
| Rear Suspension | Fully adjustable Kayaba single shock, 315 mm / 12.4 in travel |
| Front Brakes | Single 250 mm disc |
| Rear Brakes | Single 245 mm disc |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | 960 mm / 37.9 in |
| Wheelbase | 1490 mm / 58.7 in |
| Ground Clearance | 373 mm / 14.7 in |
| Dry Weight | 114 kg / 251.3 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 80/100-21 |
| Rear Tyre | 110/90-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 8 Litres / 2.1 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The 426 cc successor to the WR400F, carrying over YZ426F updates such as titanium valves and a floating front brake, plus an 18-inch rear wheel, wide-ratio gearbox and spark-arrested silencer. Still kick-start only, it was a stronger, more tractable trail and enduro bike. It was the last WR to rely on a manual compression release.
