Would a Castle bec help?
 

I have been running the castle mamba max pro esc with a castle 1415 motor in my Losi Ten-SCTE. I recently got a Tekin Pro 4 4600 kv motor. The motor runs great but right out of the box I noticed that the motor was to hot to touch after running and that my esc was pretty warm. I also found that with this new motor I can barely run 7 minutes before my battery is dead, with the castle motor i could run 12 minutes. I'm running a 13 tooth pinion gear and my batterys are orion 5000mah 90c lipos. Does anyone know whether a Castle bec would help or not?

Nothing's wrong. Just ROAR'S stupid 2s rule causing all those effects. Since you have ran the castle 1415 you already know how much better of a setup it is. Most of us using high Kv/2s setups get less than 10 mins. Don't need an external bec, just a bigger mah battery. As for the post under me, no need to switch brands. There's nothing wrong.

The BEC won't help as it is for a different problem. I had a problem with my castle esc and high amp draw with a similar switch. Once I switched to a different brand of ESC with my new motor, the problem went away.