Mike:

If you haven't checked, make sure the throttle trim is full open
when you plug in the battery and then run throttle stick to full
open and hold for a few seconds and see if prop glitches. This
should arm ESC to full range. My 85% mini has a 5amp ESC and
the GWS "A" lite-stick motor. I don't understand why you have
20 amps on it. If you have a computer radio, make sure that the
throttle program is at 100%
Randy