Bl control 710, Arduino and Roxxy motor problem

Other Hardware Motors, Mechanics, Power and CNC
1

Hi,

I own a pair of ESC's called BL Control 710, a pair of 2216/25 Roxxy motors and an ArduPilot Legacy which features an ATmega328p.

The motors are connected to pins 3 and 11 on the Arduino. From what I know, these pins are running at 976.5625Hz. My ESC's are made for 10Khz. I have to say, all the pins are already soldered on the board, so no change regarding them is possible.
The problem is that I cannot command the motor with a higher frequency than 166Hz. (6ms) I suppose the problem is related to the Arduino/ESC's timing.

I'm giving here my sketch code, for a better understanding.

void setup()
{
  Serial.begin(38400);
  pinMode(3,OUTPUT);
  pinMode(11,OUTPUT);
  analogWrite(3,0);
  analogWrite(11,0);
  delay(3000);
}

void loop()
{
  increase(0,128);
  decrease(128,0);
}

byte increase(byte from, byte till)
{
  for(byte i=from; i<=till; i++)
  {
    analogWrite(3,i);
    analogWrite(11,i);
    delay(6);
  }
}

byte decrease(byte from, byte till)
{
  for(byte i=from; i>=till; --i)
  {
    analogWrite(3,i);
    analogWrite(11,i);
    delay(6);
  }
}

What could be the solution for this situation?

Thank you for the assistance,
RobertEagle

EDIT: 1.Just for the record, I don't understand why I can't command the motors with values lower than 60-80. Don't blame the real voltages, they're okay.
2.I also found I can command them with 5.85ms and 1.3ms delay.
3.Do I have to increment the duty cycle gradually, or is just a particularity generated by my Arduino's frequency?