| MODEL | YAMAHA RD 250 1978 |
| Year | 1978 |
| Engine Type | Two stroke, torque induction, parallel twin |
| Displacement / Capacity | 247 cc / 15.0 cu in |
| Bore X Stroke | 54 x 54 mm |
| Compression Ratio | 6.7:1 |
| Cooling System | Air cooled |
| Max Power | 22.3 kW / 30 hp @ 7500 rpm |
| Max Torque | 2.9 kgf-m / 21 lb-ft @ 7000 rpm |
| Ignition | Battery and coil with breaker points |
| Induction | 2 x Mikuni VM28 SC carburettors |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | Autolube |
| Gear Box | 6 Speed |
| Clutch | Wet multi-plate |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | Telescopic forks |
| Rear Suspension | Dual shocks |
| Front Brakes | Single 267 mm disc |
| Rear Brakes | Single 267 mm disc |
| DIMENSION SPECS | |
| Overall Length | 1995 mm / 78.5 in |
| Overall Width | 830 mm / 32.6 in |
| Overall Height | 1085 mm / 42.7 in |
| Seat Height | — |
| Wheelbase | 1325 mm / 52.1 in |
| Ground Clearance | 150 mm / 5.9 in |
| Dry Weight | 152 kg / 335 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.00S-18-4PR |
| Rear Tyre | 3.50S-18-4PR |
| FUEL SYSTEM | |
| Fuel Capacity | 16.5 Litres / 4.2 US gal |
| Fuel Consumption | — |
| Top Speed | — |
Air-cooled RD250 road bike: a quick, light two-stroke twin for its class with a six-speed gearbox, Autolube oil injection and about 30 hp. The 1978 version carries over the double 267 mm disc brakes of the year before.
