title_body: Unrecognised ESC motor connector
upvoted_answer: I agree, it looks like a Micro Deans plug. They're good for about 10amps. A red JST plug is good for about 5amps. A speed 400 is pretty inefficient over about 5amps.
  Personally I'd junk both the ESC and motor and go brushless. You'll save weight, gain efficiency, be able to use a bigger prop and it won't wear out. And that ESC probably doesn't have a lipo-friendly low voltage cut-off.