Yamaha SR250 (1978-79)

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.

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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