KTM 125 SX
Although KTM has been offering motocross models for much longer, the series did not receive the SX designation until 1993. A name that inevitably recalls the legendary American racing series Supercross, which also uses the abbreviation SX and where an extremely powerful motorcycle is required to win, both in terms of chassis and engine. These characteristics fit perfectly with the brand slogan Ready to Race and have enabled KTM to develop one of the most powerful bikes in its class over the years.
The SX 125 has gone through numerous stages of evolution over time. KTM repeatedly focused on innovation, for example with the introduction of the PDS system, a shock absorber without linkage, introduced in 1998 and discontinued in 2011, with a hydraulic clutch that was considered pioneering in motocross since it was already available before 2000, with an extremely versatile WP air suspension, and finally with the introduction of a fuel injection system for 2-stroke engines.
Technical specifications KTM SX 125 2012 to 2015
Engine:
- Type: Liquid-cooled 2-stroke single-cylinder with power valve
- Displacement: 124.8 cc
- Bore x stroke: 54 x 54.5 mm
- Piston: Dual-ring piston
- Lubrication: 1:40 mixture (2-stroke oil, JASO FD 100% synthetic standard)
- Ignition: DC CDI Kokusan
- Intake: Reed valve
- Fuel system: Keihin PWK 38S carburetor
- Main jet: 182
- Pilot jet: 42
- Needle: NOZI
- Clutch: Multi-disc wet clutch (Brembo hydraulic actuation)
- Starter: Kickstarter
- Spark plug: NGK BR9 ECMVX
- Transmission: 6-speed (Oil 15W50, JASO T903 MA2 standard)
- Final drive: 13/50
Maintenance: KTM recommends replacing the piston every 20 hours and changing the gear oil every 10 hours. Check your owner's manual to find all information regarding settings and maintenance.
Useful tip: A table with all carburetor settings depending on conditions such as temperature, altitude, mud, or sand can be found in the owner's manual. This manual is available on the KTM website. It is very important to follow these guidelines to maintain the reliability and performance of your 125.
Chassis:
- Frame: Chrome-molybdenum steel tube frame with aluminum subframe
- Fork / travel: WP MXMA (Ø 48 mm with steel springs) / 330 mm, recommended oil: SAE 5
- Shock absorber / travel: WP DCC with linkage / 300 mm, recommended oil: SAE 2.5
- Front brake: 260 mm disc
- Rear brake: 220 mm disc
- Dry weight: 91.6 kg
- Seat height: 992 mm
- Front tire: 80/100-21
- Rear tire: 100/90-19
- Tank capacity: 7.5 l (Super Plus 98 recommended)
Maintenance: KTM recommends an oil change for the fork and shock absorber every 40 operating hours. Check your owner's manual to find all information regarding settings and maintenance.
KTM SX 125 in our online shop
In our online shop, we aim to offer quality parts with short delivery times and at the best price. For your 125 SX, you will find chain kits, fork seals, and oil for regular maintenance, as well as parts for customization such as plastic kits, handlebars, grips, levers, and more.
