B25 Starfire

1967 BSA B25 Starfire Technical Analysis & Specification Breakdown

Positioned in BSA's allround motorcycle lineup, the 1967 BSA B25 Starfire pairs a 247 cc (15.1 cu in) air-cooled single cylinder, four-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 25.5 HP (18.6 kW) at 7,250 rpm, transferring power to the rear wheel through chain final drive. With a specific output of 103.2 HP per liter, the engine character is reflecting a performance-oriented street tune that balances strong mid-range pull with an energetic top-end rush.

On the scales, the B25 Starfire measures 142.9 kg (315 lbs) dry, translating to a power-to-weight ratio of 0.18 HP/kg (5.6 kg per horsepower). Rider ergonomics and chassis geometry center around a 813 mm (32 in) seat height — offering a neutral standover height that accommodates most average-inseam riders without sacrificing cornering clearance, combined with a 1,346 mm (53 in) wheelbase engineered for quick, flickable steering geometry.

Within MotoLibrary's BSA archive, this model family spans 3 indexed model years from 1967 to 1969, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.