The Yamaha RD250 (1977) is a two-stroke motorcycle that features a 247cc parallel twin engine with a bore x stroke of 54 x 54 mm. The engine uses torque induction and has a compression ratio of 6.7:1. It is cooled by air and lubricated by Autolube. The bike is equipped with two Mikuni VM28 SC carburetors and battery/coil ignition with breaker points, starting with a kick. It generates a maximum power of 30 hp at 7500 rpm and a maximum torque of 21 lb-ft at 7000 rpm. The clutch is wet multi-plate and has a six-speed transmission with a chain final drive. The gear ratio includes 1st 19.67, 2nd 13.6, 3rd 10.08, 4th 7.59, 5th 6.79, and 6th 6.01. The front suspension is telescopic forks, while the rear suspension has dual shocks. The bike features a single 267mm disc for both front and rear brakes. The dimensions are 1995 mm in length, 830 mm in width, and 1085 mm in height, with a wheelbase of 1325 mm and a ground clearance of 150 mm. The Yamaha RD250 has a dry weight of 152 kg and a fuel capacity of 16.5 liters.
Technical specifications:
Make Model: Yamaha RD 250
| Year | 1977 |
|---|---|
| Engine | Two stroke, torque induction, parallel twin |
| Capacity | 247 cc / 15.0 cu-in |
| Bore x Stroke | 54 54 mm |
| Cooling System | Air cooled |
| Compression Ratio | 6.7:1 |
| Lubrication | Autolube |
| Induction | 2x Mikuni VM28 SC carburetor |
| Ignition | Battery and coil with breaker points |
| Starting | Kick |
| Max Power | 30 hp / 22.3 kW @ 7500 rpm |
| Max Torque | 21 lb-ft / 2.9 kgf-m @ 7000 rpm |
| Clutch | Wet multi-plate |
| Transmission | 6 Speed |
| Final Drive | Chain |
| Gear Ratio | 1st 19.67 / 2nd 13.6 / 3rd 10.08 4th 7.59 / 5th 6.79 / 6th 6.01 |
| Front Suspension | Telescopic forks |
| Rear Suspension | Dual shocks |
| Front Brakes | Single 267mm disc |
| Rear Brakes | Single 267mm disc |
| Front Tyre | 3.00S-18-4PR |
| Rear Tyre | 3.50S-18-4PR |
| Dimensions | Length 1995 mm / 78.5 in Width 830 mm / 32.6 in Height 1085 mm / 42.7 in |
| Wheelbase | 1325 mm / 52.1 in |
| Ground Clearance | 150 mm / 5.9 in |
| Dry Weight | 152 kg / 335 lbs |
| Fuel Capacity | 16.5 Liters / 4.2 US gal |
