Classic95, did you have a look at the motor pulley before sending it in? The lisping sound from the misaligned pulley was an easy fix on my Tecnodec, which has the same DC motor as the Gyro. In fact another user of the Tecno wrote to me with exaclty the same problem. Looks like the pulley on many new Tecnos and Gyros is just not mounted correctly from the start.
Rene
Rene