title_body: Motor will not go above half thrust. Why and how to fix?
upvoted_answer: This sounds very much like like a PWM/analog ESC miscalibration issue to me. PWM ESCs required signal calibration to ensure that both the RC receiver and the ESC are on the same page about what kind of pulse length constitutes both 0% and 100%, as there can be clock speed discrepancies and other issues with the protocol.
  
  I can't exactly find a source I like for this procedure to explain it better, so here's my rendition: (modified from those listed here)
  
  With ESC power unplugged, connect the ESC signal to the receiver's throttle channel.
  Turn on the transmitter and receiver and move the throttle to 100%.
  Enable power to the ESC and wait for it to beep a few times indicating it's in calibration mode.
  Briskly lower the throttle channel to 0% and wait for the ESC to beep to indicate it's now calibrated
  Try to operate the ESC like normal and see if the full-throttle range has been restored