2025 KTM 300 SX

For the diehard motocrossers, the only thing better than an open-class two-stroke is an even bigger open-class two-stroke. Meet the KTM 300 SX. After years of success in the off-road ranks, KTM finally gave the venerated 300cc two-stroke platform its own purebred motocross chassis, birthing the 300 SX in 2023. Now in only its third model year, the 300 SX continues to gain notoriety with an appealing power-to-weight ratio that was once only available as an accessory bore kit for the 250 SX.

The 293cc two-stroke is not eligible to race in AMA Pro Racing (which limits two-stroke engine size to 250cc in the premier class), so you won’t be seeing any in Supercross or Motocross Nationals. But you will find it a popular option among vet riders, who race according to age classes rather than displacement.

Throttle body injection (TBI) Keihin EFI handles fueling, although riders still need to add premix to the gas. An electronic power valve aims to deliver power in the snappy style that motocross two-strokes are known for, rather than the flatter, torquier power buildup of KTM’s off-road 300 bikes, the XC and XC-W. Electric start, handlebar-mounted engine map select switch, WP Xact air fork, and Brembo clutch and brake hydraulics are standard equipment. For 2025 the KTM 300 SX receives the same updates as the rest of the SX model line including a new frame, updated suspension settings, new bodywork, and fresh graphics.

The 2025 KTM 300 SX is available in orange for $9,599.