Spanish based brand Ultimate Racing has launched their new MXR Ceramic 3 Transfer .21 Offroad Competition Engine. Like its predecessor the MXS, this engine is manufactured by the prestigious Japanese brand O.S. Engines and in this case based on their square stroke Speed B21 engine. Apart from the modifications that the MXS already had, such as the crankshaft and back plate, the sleeve of the MXR has been modified, modifying the ports to be able to vary the inlet and exhaust timing. The inner head has also been modified and includes the innovative FlowMax venturi to improve performance, more specifically,…