Suzuki RM-Z250

The Suzuki RM-Z250 is the quarter-litre four-stroke motocross bike in Suzuki Motor USA's competition range, and the maker's 2026 model page describes it as a versatile machine that remains popular with professionals and privateers. Its 249 cc single-cylinder engine is liquid-cooled, with four valves, double overhead camshafts and a center-port head, and it is fed by a dual-injector electronic fuel injection system. The bore and stroke are 77.0 mm by 53.6 mm, power passes through a wet multi-plate clutch and a five-speed constant-mesh gearbox, and Suzuki states a curb weight of 106 kilograms. Tuning of the fuel injection and ignition is done with the smartphone-based MX-Tuner 4.0 or the fuel-coupler system, and an advanced traction management system adjusts ignition timing and injector duration from throttle, engine speed and gear position. The page notes that the RM-Z250 is designed for closed-course competition use only.