Twin cylinder air cooled two-stroke, 247cc, B/S 54x54mm. Water-cooling was introduced in mid-1954.
Amal TT carburettors
two ignition coils
Lubrication: 25:1 petroil mixture.
Max speed: 192 km/h
Weight: 110 kg
Wheels: 18 or 19", 36 spoke alloy rims
Brakes: 180mm x 30mm. (SLS front is standard)
Tyres: 18 or 19"
Fuel tank: Alloy, various sizes and styles.
Rear suspension: swinging arm with dual hydraulic dampers.
Front suspension: leading link with integral damping.
Twin expansion chambers.
Around ten RS250 machines were sold to privateers, and they continued to appear at the tracks until about 1960 by which time the best of them were putting out 38 horsepower.