I rewind brushless 4250 650kv motors .
original winding is 6 turns , rewind it to 3 turns , so it convert to 1300 kv motor.
kv means rpm/volt , means 1 volt = 1300 rpm
when we change winding for double kv rating then current of motor willnot double it will be square root , means I² so power of motor will also increase.