K 125 S

1976 Hercules K 125 S Technical Analysis & Specification Breakdown

Engineered by Hercules for the naked motorcycle segment, the 1976 Hercules K 125 S relies on a 124 cc (7.6 cu in) air-cooled single cylinder, two-stroke powerplant. In factory specification, peak output is rated at 17 HP (12.4 kW) at 7,500 rpm, transferring power to the rear wheel through a 6-speed gearbox and chain final drive. With a specific output of 137.1 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 K 125 S measures 122 kg (269 lbs) wet (curb), translating to a power-to-weight ratio of 0.14 HP/kg (7.18 kg per horsepower). The 11-liter (2.9 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 117 km/h (73 mph).

Within MotoLibrary's Hercules archive, this model family spans 6 indexed model years from 1974 to 1979, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.