As you move the weight further back it has more leverage - so it will tend to dunk the motor further in the water, waves coming into the stern dont provide any lift until after they have passed under the motor ie the motor get a lot wetter and if you haven't got a high transom you can end up getting heaps of water over the back which drops it even further and thats always when some big fat scuba diver is trying to climb on board - Just my thoughts, I wouldn't do it unless you had high sides and transom.