The OP has several issues contributing to his overheating:

1) He is using the wrong motor, the Kv is too high for 4S, it is more suitable for 3S but still high. A Kv of 1800-2200 would be suitable for his model on 4S.

2) Running the boat extensively at part throttle is VERY hard on the ESC and will overheat it. The hotter the setup the worse the overheating will be.

3) The battery is inadequate, today a 30C battery has excessive internal resistance, that is one reason the battery is hot.

4). The power wires to the ESC may be too long/too small in diameter. Or the connectors may have too high resistance. Or both.

5) The caps are hot because the battery cannot supply enough current under high load, this is most commonly caused by long/thin battery wires or weak batteries, or both.

The simplest solution for the OP is to try a larger prop on 2S with his current setup. And reset the transmitter to give full throttle, remembering to avoid excessive part throttle running.


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