[ringadingh]

To me the fact that the squeeling stops when you clean the filter, makes it seem to be more of a design problem by Kawasaki.
The pump is not the problem, its the filter assembly as you already found out.
Normally you shouldn't be replacing the pump or cleaning the filter as often as you are. This leads me to beleive that you have dirty fuel that is causing this to happen.
I don't think there is much you can do about that, if that is the case.
Try to find a gas station that has clean tanks if you can.