Ktm Sx 125
The KTM SX 125 was introduced in 1994 as part of KTM's motocross racing lineup, designed to compete in the 125cc two-stroke motocross class. Over the decades it became one of the most successful and dominant 125cc motocross bikes in the world, winning numerous championships and becoming a benchmark for performance in its class. It is highly regarded for its razor-sharp handling, powerful two-stroke engine, and continuous development, making it the go-to choice for amateur and professional riders alike.
~34 hp
Power
~25 Nm
Torque
~98 kg
Weight
~110 km/h (estimated; top speed varies significantly based on gearing and track conditions)
Top Speed
Estimated 4–6 L/100km (note: varies greatly depending on riding intensity; two-stroke motocross bikes are not typically measured by standard fuel economy metrics)
Fuel
Naked
Body
What Buyers Should Know
Top-End Rebuild Intervals
The KTM SX 125 requires piston and ring replacement every 15-25 hours of hard riding due to its high-revving 2-stroke engine. Always ask sellers for maintenance logs to verify top-end history.
Strong Resale Value
KTM SX 125s hold their value exceptionally well compared to Japanese competitors, often retaining 70-80% of value after one season. Orange bikes with documented service history command a noticeable premium.
Power Valve Maintenance
The BVEP power valve system is a known weak point and must be cleaned every 40-50 hours to prevent carbon buildup and power loss. Neglected power valves are one of the most common issues found on used examples.
Full Specifications
Rivals & Alternatives
Bikes that buyers cross-shop with the Ktm Sx 125
