When I had my MM, it would heat up quick even with an external BEC and 2 fans on it (a 90mm and a 40mm). The only thing I didn't try was the additional caps so I hope that's the answer to the heat issues. I was running off 3s and 12nimh too. I ended up sellingthe MM cuz I just couldn't keep it cool. On 3s I'd go with the 2650kv. Good luck.