1977 Yamaha YZ250 Specifications and Specs
Specifications and workshop reference information for the 1977 Yamaha YZ250, 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 | 2-stroke, torque induction, single-cylinder |
| Displacement | 246 cc |
| Bore × Stroke | 70.0 × 64.0 mm |
| Compression Ratio | 6.6:1 |
| Maximum Power | 38 horsepower |
| Maximum Torque | 22–25 ft-lb = 30–34 N·m |
| Carburetor | Mikuni VM38SC | Replacement Options |
| Lubrication | Premix |
| Fuel Mix Ratio | 20:1 | Premix Calculator |
| Ignition | CDI |
| Spark Plug | NGK B8ES |
| Spark Plug Gap | 0.6 - 0.7 mm |
Transmission
| Transmission Type | 5-speed constant mesh |
| Clutch | Wet multi-plate |
| Final Reduction | Chain drive |
Dimensions
| Overall Length | 85.9 inches (2,182 mm) |
| Overall Width | 26.2 inches (686 mm). |
| Overall Height | 1,270 mm (50 inches) |
| Wheelbase | 57.9 in |
| Ground Clearance | 11.8 in |
| Fuel Tank Capacity | 2.6 US gal |
| Bearing Sizes |
Bearing Finder |
Chassis
| Frame Type | Steel frame |
| Front Suspension | Telescopic forks | Fork Oil Levels |
| Rear Suspension | Monocross single shock |
| Front Suspension Travel | 9.8 inches (250 mm) |
| Rear Suspension Travel | 9.6 inches (approx. 244 mm) |
Brakes & Wheels
250cc Other Specs
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