| MODEL | BSA B25 STAR 1970 |
| Year | 1970 |
| Engine Type | Single cylinder, four-stroke, OHV |
| Displacement / Capacity | 247 cc / 15.07 cu in |
| Bore X Stroke | 67.0 mm x 70.0 mm |
| Compression Ratio | 9.5:1 |
| Cooling System | Air |
| Max Power | 19.0 kW / 26.0 hp @ 7250 rpm |
| Max Torque | — |
| Ignition | — |
| Induction | — |
| Start System | — |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 4-speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | — |
| Rear Suspension | — |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | 135.0 kg / 297.6 lb |
| WHEEL SPECS | |
| Front Tyre | 3.25-18 |
| Rear Tyre | 3.50-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 14.0 Litres / 3.70 US gal |
| Fuel Consumption | — |
| Top Speed | 135.0 km/h / 83.9 mph |
The 1970 B25 Star, a 250 cc OHV unit single with a lower compression ratio than the earlier Starfire. It was a general-purpose road bike for the lightweight market.
