REEDY SONIC 540 M4 BRUSHLESS MOTOR 6.5T MODIFIEDREEDY SONIC 540 M4 BRUSHLESS MOTOR 6. 5T MODIFIED After months of development, Reedy is proud to announce the release of the Sonic 540 M4 Competition 1: 10 Brushless Motor! Internally, the 540 M4 is very similar to that of the 540 M3 that it replaces it produces the same linear powerband and excellent mid range feel that have become synonymous with Reedys modified motors. However, changes can be good when they serve a purpose. In the case of the 540