| MODEL | AERMACCHI HD 125 ZEFFIRO 1958 |
| Year | 1958 |
| Engine Type | Single cylinder, two-stroke |
| Displacement / Capacity | 123 cc / 7.51 cu in |
| Bore X Stroke | 52 x 58 mm / 2.0 x 2.3 in |
| Compression Ratio | 5.7:1 |
| Cooling System | Air |
| Max Power | 3.6 kW / 5 hp @ 4500 rpm |
| Max Torque | — |
| Ignition | — |
| Induction | Carburettor (Dell'Orto) |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 3-speed |
| Clutch | Wet multiplate |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | Telescopic fork |
| Rear Suspension | — |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | 92 kg / 202.8 lb |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 2.25-17 |
| Rear Tyre | 2.25-17 |
| FUEL SYSTEM | |
| Fuel Capacity | 6.5 Litres / 1.7 US gal |
| Fuel Consumption | — |
| Top Speed | 78 km/h / 48.5 mph |
The Zeffiro 125 was Aermacchi's small two-stroke commuter, a light 123 cc machine with a three-speed gearbox and two separate seats. It was built as cheap everyday transport and sold in the US as a Harley-Davidson badged lightweight.
