| MODEL | BENELLI 650 TORNADO S2 1973 - 1974 |
| Year | 1973 - 1974 |
| Engine Type | Parallel twin, four stroke, OHV, 2 valves per cylinder |
| Displacement / Capacity | 642.8 cc / 39.2 cu in |
| Bore X Stroke | 84 x 58 mm |
| Compression Ratio | 8.0:1 |
| Cooling System | Air cooled |
| Max Power | 38.8 kW / 52 hp @ 7200 rpm |
| Max Torque | — |
| Ignition | — |
| Induction | 2 x Dell'Orto VHB 29 carburettors |
| Start System | Electric and kick start |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 5 speed |
| Clutch | Multiplate, wet |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | Marzocchi telescopic hydraulic forks |
| Rear Suspension | Swinging arm, adjustable shocks |
| Front Brakes | Drum, 4 leading shoe |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | 210 kg / 463 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.50-18 |
| Rear Tyre | 4.00-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 17 Litres / 4.5 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The Tornado S2 was one of the last versions of Benelli's pushrod 650 parallel twin, built to take on the British twins of the day. The S models added electric starting and twin carburettors over the earlier Tornado. It revved freely but needed high revs to make its power, and was soon overtaken by Benelli's own multi-cylinder bikes and Japanese rivals; the Tornado was dropped in 1976.
