I don't know what gear redcution you have but a 16 by 16 three blade sounds like way too much prop. On the V-40's we found a 15 by 10 three blade (as I keep recommending) worked best. I think the reduct ws 2.57 to 1 as I recall. You can go with a two blade prop at the size I have already recommended but I don't think that will "fix" anything but it will give you the engine rpms you need and good boat speed. Your excessive prop walk may have to do with all that pitch you now have. What you have now is what we call a "square prop" and they seldom work well.
Gotcha, thanks for the info I will see what I can do to find a prop matching what you say.
Also, the ratio is 2:51 to 1.