Motorcycle specifications KTM300 SX 2027 The big thrills

The 2-stroke remains unmatched when it comes to explosive engine performance. With the 300 SX, we’ve reached a formidable level in terms of power-to-weight ratio. Now, with insights drawn directly from the KTM Factory Racing teams and a maintenance kit labeled "Go get 'em," the KTM 300 SX is designed for one task—to lead the way.

Performance

The 300cc 2-stroke engine brings a new weapon to the MX Open class and offers more options to riders seeking maximum power for minimum weight. With reduced maintenance costs and a total engine weight of just 23.9 kg, the KTM 300 SX delivers pure performance. It has more than enough to satisfy them.

Selectable Map Settings

KTM SX models are equipped with a map selection switch that allows the rider to switch between maps. Mode 1 ensures linear and predictable power delivery, while Mode 2 provides greater explosiveness.

Simplified suspension adjustment

As always, the suspension is easy to adjust tool-free at both ends, allowing riders to aim for the podium with complete control. At the rear, a dual hand-adjustable compression option lets riders fine-tune high- and low-speed settings in seconds. The front fork is also easily adjustable thanks to hand-adjustable ratchets on the bottom of the fork leg and on the top cap.

Electronic Fuel Injection System

The electronic fuel injection system, now standard on all 2-stroke models in the KTM SX lineup, marks an improvement over pre-mixes. It also puts an end to lengthy pre-race carburetor tuning sessions. And thanks to the latest Keihin electronic fuel injection system and the design of the diaphragm insert, you can count on maximum power delivery at all times, regardless of altitude. Since 2026, there’s been a new fuel cap: you’ll still have quick and easy access for maintenance, but now with greater protection against external damage and accidental opening, as well as to prevent dirt from entering the sides of the connector.

Electric Start

Just press the starter button to get back on the track. That’s the reality with KTM SX models. Thanks to a 12.8V, 2Ah lithium-ion battery located under the rider’s seat, a high-quality starter and power outlet, and a super-robust design, the only thing you’ll be kicking is the competition.

Ease of Maintenance

The KTM SX and SX-F line is designed to give riders easy access to replacement parts and suspension adjustments. This speeds up track-side and off-season maintenance and simplifies motocross for novice riders who don’t have a pit crew.

Electronic Fuel Injection + Exhaust Valve Control

Handling is significantly improved thanks to the electronic fuel injection system. In addition to electronic fuel injection and the power valve on KTM SX models, this delivers more usable power across the entire rpm range. This results in improved traction.

Total Control

The KTM SX and SX-F models have received major frame updates, directly derived from the efforts of KTM Factory Racing. First, the area around the rear shock has been streamlined, with engine mounts and cutouts to improve chassis flexibility. The front section of the frame features optimal wall thickness with redesigned engine mounts.

Ergonomics

The two-component plastic tank guards channel air to the radiators more efficiently, while a compact fuel tank roll allows for a tighter and more secure fit, reducing the risk of frame rubbing and significantly improving durability. All of this works in conjunction with the rider triangle, which is specifically designed to provide unmatched grip and knee contact surfaces, particularly when standing on the footpegs.

WP XACT Fork

The 48 mm WP XACT AER forks fitted to the KTM SX and SX-F models feature a sealed air spring and a pressurized oil chamber for progressive and consistent damping, while oil and air bypasses reduce pressure spikes. Combined with the floating-piston damping system, it ensures excellent feedback and remarkable comfort. The fork also features adjustments that not only complement the frame and rear linkage but also guarantee exceptional performance across the board. It can be easily adjusted for preload using a simple air valve, as well as for compression and rebound via the easily accessible adjustment knobs. Additionally, the WP air pump required to adjust the fork pressure is included as standard in the buy-pack.

WP XACT Shock

At the rear, the WP XACT shock absorber uses settings directly derived from the KTM Factory Racing teams. The frame and shock absorber geometry provides greater ground clearance at the linkage, making it less prone to bottoming out. The small-diameter linkage bolts help save weight, while the new linkage seals improve rear shock response and advanced damping characteristics.

Stability

The KTM Motocross range is equipped with a special rear brake pedal that adds stiffness, flex resistance, and braking feel to the assembly. At the other end, a forged steering head and a CNC-machined fork crown ensure perfect alignment of the fork tubes. This precise geometry of the fork clamps ensures high responsiveness and smooth fork action, not to mention unwavering stability when riding through ruts and on the podium.

Tires

Dirt and performance rarely go hand in hand. However, hours of research and testing have led the KTM Motocross range to the Dunlop GEOMAX MX34. Offering unmatched stability and control at the highest level, the tire features a rigid casing and a rubber compound that improves damping and absorption, maintaining performance up to 30% longer than previous models. Progressive Cornering Block technology also improves grip in berms, while the rear tire features a wide, tall center block for desirable traction and control everywhere else. Finally, this unique block layout helps disperse mud buildup, ensuring traction even in very muddy conditions.

Energy Absorption

In addition to the hydroformed, laser-cut, and robot-welded frame—designed to provide exceptional feedback to the rider and straight-line stability—the chassis features specifically calculated longitudinal flex and torsion parameters. The frame thus acts as a shock absorber, resulting in a smoother ride and less fatigue over the course of laps.

Ground Clearance

No one enjoys unexpected crashes. Fortunately, the suspension geometry on the KTM SX and SX-F models provides ample ground clearance for the linkage, while the topography-optimized die-cast footpegs are less likely to catch in deep ruts or lift off in rough terrain.

Smoother Performance

Count on a durable chain guide and chain guard to minimize the risk of snagging on external objects, especially in extremely muddy conditions, while reducing dirt buildup around the swingarm and rear sprocket. Since 2026, the mounting points have been modified, and the cable routing is less prone to wear and damage.

Information and image credits: KTM