I know that it will effect RPM and top speed, but will a lower pitch make a change in the wake? Also I'm looking at going from a 3 blade to a 4 blade on a Force 120, will that make a difference. thanks <BR>

It could make a difference in the center of the wake, in the turbulance, airation, "rooster tail", etc. I would expect a four bladed prop to yield a smoother center. <BR> <BR> The shape of the wake is established by the hull of the boat, the weight, and the torque from the motor. Going to a four bladed prop will increase the drag slightly, which in turn will cause a slight increase in torque, which could make the boat lean slightly differently. I would expect these effects to be so small that I doubt that you would notice any difference.