This looks very much like a bayonet... which i dont mind but... if you look at the bayonet the back of it where the engines are are well done. This however... the engines are quite exposed. There is nothing to hid them and therefore the back to me looks quite unpleasant. Since that is the part that we will look at the most I would suggest adding some sexyness to the back please.
Add some curve element to it. You know the part of a bike that is supposed to block dirt from coming up with the wheel? maybe have something like that to hide the engines? Or make the engines maybe 4 exhaust or something. Right now they are tiny and boxy... and not elegant.