| MODEL | YAMAHA YDS-7 1972 |
| Year | 1972 |
| Engine Type | Two stroke, piston-port, parallel twin |
| Displacement / Capacity | 247 cc / 15.0 cu in |
| Bore X Stroke | 54 x 54 mm |
| Compression Ratio | 7.5:1 |
| Cooling System | Air-cooled |
| Max Power | 30 hp @ 7500 rpm |
| Max Torque | 21 ft-lb @ 7000 rpm |
| Ignition | Mitsubishi contact breaker |
| Induction | 26 mm Mikuni |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 5 Speed |
| Clutch | Wet, multi-plate, mounted on left side of crankshaft |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | 34 mm telescopic forks |
| Rear Suspension | Twin shock |
| Front Brakes | 180 mm twin leading shoe drum |
| Rear Brakes | 180 mm single leading shoe drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | 1300 mm / 51.1 in |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | 145 kg / 320 lbs |
| WHEEL SPECS | |
| Front Tyre | 3.00-18 |
| Rear Tyre | 3.25-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 11.4 Litres / 3.0 gal |
| Fuel Consumption | — |
| Top Speed | — |
The YDS-7 is the last of the YDS line of 250 cc air-cooled two-stroke twins, with a more powerful 30 hp engine than its 1960s forebears, a 26 mm Mikuni carburettor and a five-speed gearbox. It is a light, lively sports roadster.
