2015 Ktm 125 SX, Save more than 1,600$$ instantly on our UNBEATABLE sale price!! Call Motoworld at (619) 442-0941 today! - The 125 SX has long since established itself as the undisputed top dog above all in junior race series and as a springboard to the professional leagues. Powered by a high-performance 2-stroke engine with exhaust control system and 6-speed transmission, the 125 SX has been further improved for the 2015 model year, ensuring it will maintain its popularity with young champions in future.