Engineered by Ktm for the enduro - offroad motorcycle segment, the 2020 Ktm 125 SX features a 124.8 cc (7.6 cu in) liquid-cooled single cylinder, two-stroke configuration. In factory specification, peak output is rated at 15 HP (10.9 kW), transferring power to the rear wheel through a 6-speed gearbox and chain final drive. With a specific output of 120.2 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 125 SX measures 137 kg (302 lbs) dry, translating to a power-to-weight ratio of 0.11 HP/kg (9.13 kg per horsepower).
Within MotoLibrary's Ktm archive, this model family spans 23 indexed model years from 2003 to 2025, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
120.2 HP/L
Power-to-Weight
0.11 HP/kg (9.13 kg/HP)
Engine
Displacement124.8 ccm (7.62 cubic inches)
Engine TypeSingle cylinder, two-stroke
Power15.0 HP (10.9 kW))
Bore x Stroke54.0 x 54.5 mm (2.1 x 2.1 inches)
Fuel SystemInjection
Fuel ControlDouble Overhead Cams/Twin Cam (DOHC)
IgnitionContactless, controlled, fully electronic ignition system with digital ignition timing adjustment, type Kokusan
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
