I'm no engineer, but there is a reason that many EDF jet have larger openings on the intake ducting, or on some, have cheater holes on the bottom or sides of the jet. Those intake openings you have on your model look small, even smaller than what would be scale to me. There is some science and engineering in airflow into intake ducting, flowing through the fan, and openings as the flow leaves the rear of the jet....

Think of it this way... Imagine trying to breath through a straw, and then imagine trying through a paper towel roll. I would think that if the hole is not big enough, then the motor would be pulling extra amps trying to "suck" in air through the ducting, just like you would have a hard time breathing through a straw.