Two-Stroke vs. Four-Stroke: KTM 150 SX vs. KTM 250 SX-F 14

When it comes to two vs. four with the small bikes, a 125 will pretty much always be outgunned by a 250F. Last time, we had a Yamaha YZ125 that was built up by Pro Circuit versus a completely stock YZ250F to see if that gap would be a little smaller. To check out that video click here - https://youtu.be/MBkjrpQ4l8U

This time, instead of modifying a 125 two-stroke, we just went with a bigger bike. The KTM 150 SX is nearly identical to the 125 SX, just with 143.99 displacement achieved by a 58mm bore cylinder. And the 250 SX-F is your standard lites class race bike. Both of the machines have full FMF exhaust systems, but other than that, are bone stock. 

As you will see in the video, both bikes have things they do better than the other. Our resident ex-pro tester David Pingree and content manager Sean Klinger represent the fast end of the spectrum and the “working class vet-speed guy” end of the spectrum, respectively. 

And let us know which Two-Stroke vs. Four-Stroke video you want to see next.