I hope that little excercise didn't damage your new ESC. If there was smoke as you say, I think it probably did.
These are the motors I run in a couple of 6s boats, Which are larger hulls than the impulse. A good price and a free water jacket.
http://www.offshoreelectrics.com/pro...p?prod=tp-4050
But I feel that the impulse is a bit small for a 6s set up. A 4s system is plenty for that hull.