1957 AJS Model 31 650 technical specifications

Technical specifications

Model: Model 31 650
Years: 1957-66
Engine: Four stroke, pushrod parallel twin, OHV, 2 valves per cylinder,
Capacity: 646 cc / 39.4 cu in
Bore x Stroke: 72 x 79.3 mm
Compression Ratio: 7.5 : 1
Cooling System: Air cooled
Induction: Carburetor
Ignition: 6 V (After 1964 12 V) Magnet (Lucas K2F)
Starting: Kick
Clutch: Multi Plate (dry, Burman)
Max Power: 31,4 kW / 43 hp @ 6000 rpm
Transmission: 4 Speed
Final Drive: Chain
Frame: Single cradle
Front Suspension: Hydraulic telescopic fork
Rear Suspension: Dual chocks
Front Brakes: Drum
Rear Brakes: Drum
Wheels: Steel, wire spokes
Front Tyre: 3.25 -19
Rear Tyre: 3.50 -19
Dry Weight: 176 kg / 388 lbs
Fuel Capacity: 16 L / 4.2 US gal

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