Reds Racing have released the all-new 521 Sport off-road engine. This new engine belongs to Reds S Line together with 721 Scuderia, Superveloce and Corsa, a new range of engines produced with different materials, from different suppliers and with new technologies. All assembled in-house and 100% made in Italy. The new engine features great reliability, tuning stability and fuel mileage and combined with specific technical changes in the porting and new materials, this 5 port engine features good power and fuel efficiency. Supplied with the same aluminium carburettor as 721 engines to guarantee reliability and tuning stability and features a new and unique high stiffness crankcase design. The engine is produced with pressure die casting, a very high quality process, while previous generation R line crankcases were produced with gravity casting.