2021 KTM 250 SX-F Dyno Test

The most powerful 250 four-stroke to spin the drum on our dyno so far

Video By: Bert Beltran

Despite being designed to run at high rpm, the 2021 KTM 250 SX-F produces some of the best horsepower and torque figures along the entire rpm range on the Dirt Rider dyno. It makes the most horsepower of all the bikes in the class from 6,100 to 6,500 rpm, 11,000 to 11,500 rpm, 11,900 to 12,400 rpm, and 12,700 rpm until peak. The orange bike churns out the most peak horsepower in the class with 41.1 hp at the highest rpm of 13,700 rpm, which is a minimum of 400 rpm to a maximum of 800 rpm higher than any other 250 four-stroke motocross bike on the market.

The KTM also produces some of the highest torque figures along the curve and is bested at peak only by a bike that shares the same engine as it—the 2021 Husqvarna FC 250. We documented 19.1 pound-feet at 9,100 rpm as the 250 SX-F’s peak torque figure for the 2021 model, which is just 0.2 pound-feet less than its Austrian relative.

2021 KTM 250 SX-F Dyno ChartMichael Gilbert

“With its high-horsepower, high-revving, high-demand engine, the 2021 KTM 250 SX-F requires a little more energy to ride and is designed more for faster, aggressive riders.” —Allan Brown

2021 KTM 250 SX-F Engine Specification

Type: Liquid-cooled, DOHC, four-stroke single-cylinder; 4 valves/cyl.
Bore x Stroke: 78.0 x 52.3mm
Displacement: 250cc
Compression Ratio: 14.4:1
Fuel Delivery: Electronic fuel injection