| General |
| Comments | - | Smartphone Connectivity. |
| Year | 1957 - 66 | - |
| Colours | - | Metallic Moondust Gray/Ebony |
| Make Model | AJS Model 31 650 | - |
| Warranty | - | 12 Month Limited Warranty |
| Dimensions |
| Ground Clearance (in.) | - | 4.9 inches |
| Ground Clearance (mm) | - | 124 mm |
| Seat Height | - | 800 mm / 31.5 in. |
| Wheelbase | - | 1405 mm / 55.3 in. |
| Height | - | 1115 mm / 43.9 in. |
| Length | - | 2065 mm / 81.3 in. |
| Width | - | 765 mm / 30.1 in. |
| Weights & Capacities |
| Dry Weight | 176 kg / 388 lbs | - |
| Fuel Capacity | 16 L / 4.2 US gal | 15.14 litres / 4.00 US gallons |
| Wet Weight | - | 187.0 kg / 412.3 lbs |
| Performance |
| Maximum RPM | - | 12500 |
| Max Power | 31,4 kW / 43 hp @ 6000 rpm | - |
| Max Torque | - | 65.7 Nm (6.7 kgf-m or 48.5 ft.lbs) @ 6500 Revolutions |
| Engine |
| CO2 | - | 103.0 CO2 g/km. (CO2 - Carbon dioxide emission) |
| Bore x Stroke (mm) | - | 83.0 x 60.0 mm |
| Bore x Stroke (in,) | - | 3.3 x 2.4 inches |
| Displacement (ci) | - | 39.60 cubic inches |
| Engine Type | - | Twin, four-stroke |
| Fuel Control | - | Double Overhead Cams/Twin Cam (DOHC) |
| Displacement (cc) | - | 649.0 cc |
| Displacement | 646 cc / 39.4 cu in | - |
| Engine Detail | Four stroke, pushrod parallel twin, OHV, 2 valves per cylinder, | Die-cast aluminium cylinder and lightweight coated pistons |
| Fuel System | - | Injection. DFI® with Keihin 36mm Keihin throttle bodies |
| Bore x Stroke | 72 x 79.3 mm | - |
| Compression Ratio | 7.5 : 1 | 10.8:1 |
| Cooling System | Air cooled | - |
| Engine Lubrication | - | Forced lubrication, semi dry sump |
| Fuel Consumption | - | 4.44 litres/100 km (22.5 km/l or 52.98 mpg) |
| Fuel Induction | Carburetor | - |
| Ignition | 6 V (After 1964 12 V) Magnet (Lucas K2F) | TCBI with electronic advance |
| Starter | Kick | Electric |
| Drivetrain |
| Clutch | Multi Plate (dry, Burman) | Assist and Slipper Clutch |
| Final Drive | Chain | Chain (final drive) |
| Gearbox | - | 6-speed |
| Primary Drive | - | Sealed chain |
| Transmission / Drive | 4 Speed | - |
| Chassis |
| Frame Type | Single cradle | Trellis, high-tensile steel |
| Suspension - Front | Hydraulic telescopic fork | 41 mm telescopic fork |
| Suspension - Rear | Dual chocks | Horizontal Back-link with preload adjustment |
| Rake | - | 24.0° |
| Trail | - | 100 mm / 3.9 in. |
| Wheel Travel - Front | - | 124 mm / 4.9 in. |
| Wheel Travel - Rear | - | 130 mm / 5.1 in. |
| Electrical Systems |
| Instrumentation | - | Dual-dial instrumentation with multi-function LCD screen |
| Lighting system | - | Round LED headlight |
| Wheels & Brakes |
| Brakes - Front | Drum | Double disc. Petal-type rotors with two-piston calipers. ABS. |
| Brakes - Rear | Drum | Single disc. Petal disc. Single-piston. ABS. |
| Rims | - | Spoke-style cast wheels. Dunlop Sportmax Roadsport 2 tires |
| Tyres - Front | 3.25 -19 | 120/70-ZR17 |
| Tyres - Rear | 3.50 -19 | - |
| Wheels | Steel, wire spokes | - |