| MODEL | YAMAHA AS3 125 1971 - 1972 |
| Year | 1971 - 1972 |
| Engine Type | Two-stroke, twin cylinder |
| Displacement / Capacity | 125 cc / 7.63 cu in |
| Bore X Stroke | 43.0 x 43.0 mm / 1.7 x 1.7 in |
| Compression Ratio | 7.0:1 |
| Cooling System | Air |
| Max Power | 11.7 kW / 16 hp @ 9800 rpm |
| Max Torque | — |
| Ignition | — |
| Induction | Port control |
| Start System | — |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 5-speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | — |
| Rear Suspension | — |
| Front Brakes | Expanding brake (drum) |
| Rear Brakes | Expanding brake (drum) |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | 105 kg / 231.5 lb |
| WHEEL SPECS | |
| Front Tyre | 2.50-18 |
| Rear Tyre | 2.75-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 9 Litres / 2.38 US gal |
| Fuel Consumption | — |
| Top Speed | 127 km/h / 78.9 mph |
The AS3 was a small two-stroke twin in Yamaha's 125 cc sports-roadster line, a later development of the AS1 and AS2. It offered a five-speed gearbox, light weight and a high-revving engine aimed at young riders wanting sporty performance in a small class.
