Couple of issues wih my Mamba Max

[BrianG]

LOL, the problem with using a smaller motor is that it will be loaded more and still draw the current to heat the ESC. It's really the mass of the truck that's the problem IMO. It takes power to get the truck moving. You'd have more motor options if the ESC handled more than 4s safely. If you don't mind using a fan, I'd stick to what you have and just use the fan and/or more heatsink area.

You might also try to reduce the timing and/or "start power" to the lowest setting. That will ease the burden somewhat and should help temps.