The RX 450 4T is back for MY26 with a host of engine refinements that bring its performance closer than ever to the factory bikes competing in MXGP and AMA Supercross.
The development of the 450cc engine focused on delivering a significant performance increase over the previous model, with a stronger, more usable torque curve across all riding conditions. This achievement was possible due to a new cylinder head with a performance-enhancing piston, a new intake manifold and a different exhaust system. The head’s overhaul – developed through CFD analysis and many flow bench calibrations – includes an improved intake duct to enhance air circulation inside the engine. The new manifold, following the flow line, has a longer internal horn to improve the tuning of pressure waves, and thus increasing volume while intaking air. The piston includes new coatings to reduce friction and improve its performance. A newly designed counter balancer was introduced to contain vibrations and reduce rider fatigue. The RX 450 4T also features a new HGS exhaust system, co-developed with HGS to create greater flow and increased power. Engine maps have been reworked for the new motor, with new start-up and limiter strategies. The RX 450 has four throttle pulleys so riders can tailor the throttle response.
