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250 SX - 2019


Model Description

KTM let its entire expertise flow into the development of the KTM 250 SX. The result is a high-performance 2-stroke engine in a state-of-the-art chassis. The 250cc engine features the best power-to-weight ratio in the world of motocross and, as a result of the outstanding performance combined with an ultra-lightweight chassis, it makes the KTM 250 SX the fastest bike in its class – on all tracks and on every terrain. An extremely serious opponent for significantly more complex 4-stroke motocross machines has emerged, with braking taken care of by the best brakes available on any motocross bike today.
To reduce the vibration levels, the KTM 250 SX engine has been fitted with a balancer shaft. This is primarily of benefit to the rider as this reduces stress and further increases the level of riding comfort.
The KTM 250 SX incorporates a DDS (damped diaphragm steel) clutch developed in-house by KTM with a robust outer clutch hub and extremely heat-resistant steel clutch plates. A diaphragm spring instead of conventional coil springs, which requires less effort to operate the clutch. This design also means that sufficient space is left to incorporate a damping system in the clutch hub. This increases traction and also extends the life of the clutch. It goes without saying that this hydraulically-operated Brembo clutch also means easy and precise action and virtually playful control.
In model year 2019, the KTM 250 SX features a newly designed header and silencer. For the production of the exhaust pipe the latest 3D stamping technology is used. The new design increases ground clearance and with a slimmer construction contributes to the very compact layout of the entire system and in addition it increases power and performance characteristics in conjunction with the upgraded silencer internals. The somewhat reduced weight of the silencer has resulted from using an aluminum bracket instead of the previous one made of plastic.
The cylinder of the KTM 250 SX with a 66.4 mm bore is fitted with a sophisticated TVC power valve, featuring a machined exhaust port, which improves the power delivery once again for model year 2019. The bike's power curve can be changed in a matter of seconds using the two power valve springs supplied, enabling the rider to optimize settings for different track conditions and to suit his own personal preferences. The lateral cylinder head brackets are now made of aluminum instead of steel. They enable the engine to be mounted more firmly to the frame to reduce vibration levels.

The 38 mm flat slide carburetor provides smooth and controllable performance throughout the entire rpm range. A new setting has been matched perfectly to the newly designed air filter box and the new exhaust system. As a result, the engine's throttle response is instantaneous and the smooth power delivery is a dream.

The 2-stroke engine of the KTM 250 SX is regarded as the most powerful engine in its class. Fitted with a TVC (twin valve control) power valve, a balancer shaft to reduce vibrations, a 5-speed transmission and a hydraulic DDS clutch, it is setting the standards in its segment. As a result of modifications to the cylinder and exhaust system, this compact powerhouse shames the competition with outstanding performance and agility, and is the right choice for all those who love that typical 2-stroke sound and low purchasing and maintenance costs.
The engine is coupled to a 5-speed transmission with gear ratios optimized specifically for motocross racing. KTM's advanced No-Dirt technology is used for the gear shift lever to prevent mud and dirt from fouling the lever joint and thus guarantees reliable gear changing at all times.
To make the cooling more effective, the engine is provided with an upgraded water pump case designed to optimize coolant flow.

Model Specification


Engine Type

Single cylinder, 2-stroke


249 cc




5 gears

Engine Lubrication

Mixture oil lubrication


Liquid cooled


Wet multi-disc clutch, Brembo hydraulics





Central double-cradle type


5/8 x 1/4

Steering Head Angle

63.9 degrees

Tank Capacity

7.5 litres


Primary Gear Ratio


Secondary Gear Ratio


Brake System Front

Disc brake 260 mm

Brake System Rear

Disc brake 220 mm


Front Suspension

WP USD AER 48 mm

Rear Suspension

WP shock absorber with linkage

Suspension Travel Front

310 mm

Suspension Travel Rear

300 mm



66.4 mm


72 mm


1485 mm

Ground Clearance (unloaded)

375 mm

Seat Height

950 mm

Weight (No Fuel)

95.5 kg