2S batteries with that motor/ESC/prop!
Used a Turnigy Nano-Tech 1800 2S 25C and noticed a much nimbler airframe. Lost a 110g too. I haven't flown it with the 2500 3S since! Ordered some of the slightly bigger 2200 2S 35C Nano-Tech's to keep me airborne more. Swapt out rudder servo works flawlessly, as it should.
CG is between 3 and 3-1/4", fyi.