1998 Yamaha WR400F
Specifications and workshop reference information for the 1998 Yamaha WR400F, including engine, chassis, service data and setup details.
Note: Specs are compiled from factory data, manuals and owner feedback. Bikes vary — if yours is different, jump into the forum and share it.
General Specifications
| Engine Type | Liquid-cooled 4-stroke single-cylinder DOHC 5-valve |
| Displacement | 399 cc |
| Bore × Stroke | 92.0 × 60.1 mm |
| Compression Ratio | 12.5:1 |
| Maximum Power | 48 hp @ 8000 rpm |
| Maximum Torque | 39 Nm @ 7500 rpm |
| Carburetor | Keihin FCR39 |
| Lubrication | Wet sump |
| Fuel Mix Ratio | N/A |
| Ignition | CDI |
| Spark Plug | NGK CR8E |
| Spark Plug Gap | 0.7–0.8 mm |
| Valve Clearance (IN) | 0.10–0.15 mm |
| Valve Clearance (EX) | 0.20–0.25 mm |
Transmission
| Transmission Type | 5-speed constant mesh |
| Clutch | Wet multi-plate |
| Primary Reduction | 2.652 |
| Final Reduction | 14/50 |
| Overall Reduction | |
Dimensions
| Overall Length | 2180 mm |
| Overall Width | 825 mm |
| Overall Height | 1280 mm |
| Wheelbase | 1485 mm |
| Ground Clearance | 375 mm |
| Fuel Tank Capacity | 13.5 L |
Chassis
| Frame Type | Steel semi-double cradle |
| Caster Angle | 27.5° |
| Trail | 117 mm |
| Front Suspension | KYB upside-down forks |
| Rear Suspension | Monocross single shock |
| Front Suspension Travel | 300 mm |
| Rear Suspension Travel | 315 mm |
Brakes & Wheels
| Front Tire | 80/100-21 |
| Rear Tire | 110/100-18 |
| Front Brake | Single disc |
| Rear Brake | Single disc |
400cc Other Specs
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