Mamba max / dx3r problem

[streethot]

I had have a problem very similar on my Kyosho TF5, I turned it on and every time I steer the car, mamba turned itseld off.......so.......to not harm the esc.....i put a external bec.....solved.......every time i tried to steer it was worst then before until the esc didnt turn on nevermore........i dont know the problem but i wont risk a good mm because its bec........btw i think mm bec is weak......and should be 6V not 5V......