MX400B
Category: Motocross
Manufacturer: Yamaha
Hits: 812
| Year | 1975 |
| Engine Class | 400 |
| VIN Prefix | 510 |
| Known VIN Range (Vehicle ID Numbers) | 000101 to 009096 |
| Tank Color(s) | White W/Comp. Yellow |
| Country of Sale | USA |
| Bore (MM) | 85 |
| Stroke (MM) | 70 |
| Displacement (CC) | 397 |
| Compression Ratio (to 1) | 7.57 |
| BHP @ RPM | 38.76 @ 8,000 |
| Torque (kgm) @ RPM | 3.92 @ 7,000 |
| Autolube Injection? | No |
| Engine Cooling | Air |
| Carburetor Model | VM38SS |
| Ignition Type | CDI (Electronic) |
| Ignition Timing MM (BTDC) | 2.7 |
| Primary Drive Gearing | 2.67 |
| Final Drive Gearing (Sprockets) | 50/14 |
| Box Gearing First | 2.25 |
| Box Gearing Second | 1.68 |
| Box Gearing Third | 1.26 |
| Box Gearing Fourth | 1.0 |
| Box Gearing Fifth | 0.79 |
| Fuel Capacity (L) | 8 |
| Gearbox Oil Capacity | 1.0 |
| Fork Oil Capacity (CC/Fork Leg) | 190 |
| Front Tire (stock) | 3.00 x 21 |
| Rear Tire (stock) | 4.60 X 18 |
| Front Brake Type | Drum |
| Rear Brake Type | Drum |
| Rear Suspension | Mono Shock |
| Front Suspension Travel (mm) | 190 |
| Rear Suspension Travel (mm) | 90 |
| Rake (degrees) | 31 |
| Trail (mm) | 139 |
| Overall Width (mm) | 985 |
| Ground Clearance (mm) | 235 |
| Wheelbase (mm) | 1,415 |
| Dry Weight (kg) | 103 |