2023 KTM 125 SX

The 2023 KTM 125 SX sits at the entry point of KTM's two-stroke motocross line, the machine young racers move into once they've outgrown 85cc competition. This is a full-size, race-only motocross bike built around a small-bore two-stroke engine, which means it demands a rider who knows how to keep momentum up and work a powerband rather than lean on low-end torque. It's light, flickable, and rewards clean technique over brute force, which is exactly why it's remained a fixture in amateur national-level racing paddocks. Ownership means living with two-stroke maintenance habits: premix fuel, top-end rebuilds on a schedule, and jetting adjustments as conditions change, not a bike you park and forget between motos.

The 2023 model carried over without significant mechanical changes from the prior year — buyers comparing it to a 2022 example should focus on mileage, service history, and condition rather than spec differences. Typical buyers are junior and amateur racers stepping up from 85cc machines, along with their parents shopping on behalf of a kid serious about club or regional racing. Collector interest is minimal; this is a working race bike, not a garage piece.