The Yamaha SR250 motorcycle was produced from 1978 to 1979 and had a four-stroke, single cylinder, SOHC, 2-valve engine with a capacity of 239cc. Its compression ratio was 8.9:1 and it had a 34mm Mikuni carburettor for fuel induction. The bike had a maximum power of 21hp at 7700 rpm and a maximum torque of 18.7 ft-lb at 7000 rpm. The transmission was five-speed and the final drive was a chain. The front suspension had 32mm telescopic forks and the rear suspension was dual shock with five-way preload adjustment. The brakes were drum, both front and rear. The front tire was 3.00-18 and the rear tire was 120/90-16. The wheelbase was 1340mm and the seat height was 740mm. The bike weighed 130kg and had a fuel capacity of 10.8 litres. Its average consumption was 70 mpg, and it could reach speeds up to 89 mph. The Yamaha SR250 was a reliable and efficient bike, with a moderate top speed and standing 1/4 mile time of 16.3 seconds.
Technical specifications:
Make Model: Yamaha SR 250
| Year | 1978-79 |
|---|---|
| Engine | Four stroke, single cylinder, SOHC, 2 valve |
| Capacity | 239 cc / 15.2 cu-in |
| Bore x Stroke | 73.5 x 56.5 mm |
| Cooling System | Air cooled |
| Compression Ratio | 8.9:1 |
| Induction | 34mm Mikuni carburettor |
| Ignition | Electronically |
| Starting | Electric |
| Max Power | 21 hp / 15.7 kW @ 7700 rpm |
| Max Torque | 18.7 ft-lb / T25.5 Nm @ 7000 rpm |
| Transmission | 5 Speed |
| Final Drive | Chain |
| Front Suspension | 32mm Telescopic forks |
| Rear Suspension | Dual shock 5-way preload adjustment. |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| Front Tyre | 3.00-18 |
| Rear Tyre | 120/90-16 |
| Wheelbase | 1340 mm / 52.75 in |
| Seat Height | 740 mm / 29.0 in |
| Wet Weight | 130 kg 287 lbs |
| Fuel Capacity | 10.8 Litres / 2.7 US gal |
| Consumption Average | 70 mpg |
| Standing 1/4 Mile | 16.3 sec |
| Top Speed | 89 mph / 143.2 km/h |
