KTM 50 SX / 50 SX Mini Service Manual (2014)

KTM built its small-displacement SX range as a progression path for young motocross racers, with the 50 cc class sitting below the 65 SX and 85 SX. By 2008 KTM was offering the 50 SX alongside the 50 SX Junior, while its 2009 documentation expanded the family to include the 50 SX Mini as a still smaller, lower machine for younger riders. KTM’s own model application database preserves that evolution, listing the Junior in the late 2000s and separate 50 SX and 50 SX Mini entries through the following years. The strategy was not simply to detune one motorcycle, but to offer different chassis dimensions and equipment around a shared junior-racing concept.

By 2014 the range had settled into two closely related 49 cm³ competition models. Both used a liquid-cooled, reed-induction single-cylinder two-stroke with a 39.5 × 40 mm bore and stroke, automatic centrifugal multi-disc clutch, rigid single-stage reduction transmission, kickstarter and chain final drive. Both also used chrome-molybdenum central-tube frames, WP suspension and hydraulic disc brakes at both ends. That common architecture gave younger riders the same basic mechanical character as they progressed through KTM’s mini-motocross range without introducing the size and complexity of a conventional multi-speed youth motorcycle.

The main distinction between the 50 SX / 50 SX Mini was rider fit and power-delivery hardware. The standard 50 SX used a Dell’Orto PHBG 19BS carburetor, premix lubrication, an 11:40 final-drive ratio, 205 mm of front suspension travel, 185 mm at the rear, a 1,032 mm wheelbase and a 684 mm seat height. The Mini used a smaller Dell’Orto PHVA 12XS carburetor, separate oil injection, a 10:42 final ratio, 100 mm of front travel, 171 mm at the rear, a 914 mm wheelbase and a much lower 558 mm seat height. Both weighed roughly 40 kg without fuel. This made the Mini the more accessible stepping-stone while the standard machine delivered the taller proportions expected of a junior motocross race bike.

The 50 SX platform continued to evolve after this generation, with KTM retaining the core idea of a purpose-built youth racer while updating chassis, suspension and ergonomics. A major reset came for model year 2024. In its official 2024 mini-cross announcement, KTM described the new 50 SX as a completely fresh development designed around young riders’ body proportions, with a new steel frame, height-adjustable chassis components, WP XACT suspension and a layout intended to resemble a scaled-down full-size SX. That redesign marks a clear generational break from the fixed-dimension 2014 machines.

This listing is specifically for the 2014 factory Repair Manual. The source PDF is headed “REPAIR MANUAL 2014” and explicitly distinguishes the 50 SX and 50 SX Mini throughout the suspension, carburetor, lubrication, gearing and chassis specifications. It does not list the 50 SX Junior as a covered 2014 model and does not state compatibility across 2006-2015, so the catalog is intentionally limited to 2014. Related KTM factory publications are grouped in the KTM service manual catalog.