1976 Yamaha YZ400
Specifications and workshop reference information for the 1976 Yamaha YZ400, 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 | Air-cooled, single-cylinder, 2-stroke |
| Displacement | 397 cc |
| Bore × Stroke | 83.0 × 72.0 mm |
| Compression Ratio | Approx. 7.0:1 |
| Maximum Power | Approx. 40 hp |
| Maximum Torque | N/A |
| Carburetor | Mikuni VM38SS |
| Lubrication | Premix |
| Fuel Mix Ratio | 20:1 – 32:1 |
| Ignition | CDI (magneto) |
| Spark Plug | NGK B8ES |
| Spark Plug Gap | 0.6 – 0.7 mm |
Transmission
| Transmission Type | 5-speed manual |
| Clutch | Wet multi-plate |
| Primary Reduction | 2.863 |
| Final Reduction | 3.000 |
| Overall Reduction | N/A |
Dimensions
| Overall Length | 2,180 mm |
| Overall Width | 850 mm |
| Overall Height | 1,220 mm |
| Wheelbase | 1,450 mm |
| Ground Clearance | 250 mm |
| Fuel Tank Capacity | 9.0 L |
Chassis
| Frame Type | Steel single cradle |
| Caster Angle | Approx. 27° |
| Trail | N/A |
| Front Suspension | Telescopic forks |
| Rear Suspension | Twin shock swingarm |
| Front Suspension Travel | ~200 mm |
| Rear Suspension Travel | ~100 mm |
Brakes & Wheels
| Front Tire | 3.00-21 |
| Rear Tire | 4.50-18 |
| Front Brake | Drum |
| Rear Brake | Drum |
400cc Other Specs
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