I just wanted to thank everyone for the ideas and feedback. So I had 3 causes, alignment, stuffing box lubricant and a loose prop.
As noted above, the alignment was in fact a major issue. I had thought it was aligned but using the laser guides helped me realize that when I was tightening the bolts it was pulling it slightly off alignment. I adjusted the mount and it's very close to dead center, dramatic reduction in noise.
There was also a slight noise coming from the stuffing box nut. It wasn't dripping enough. I loosened up the nut so I had a drip ever 5 seconds and this got rid of that noise.
Re: prop loose: after free-diving it took me an hour to pull the cotter ping out of the castle nut to see that the prop was in fact loose. I tapped the prop back up the tapered prop shaft about 1/2 inch. Space now between the cutlass bearing and the prop is about 1 inch. I was able to use my hand to tighten up the bolt to where it was touching the prop and then a large wrench to tighten it a 1/4 turn to align up the cotter pin. This was a bit difficult free diving to do all this as my face mask kept fogging up
but I got the job done.
Way less noise, no knocking sounds. I also had a vibration at certain RPM which is reduced dramatically now.
I'll check it after a few times motoring in and out of the slip to make sure nothing is slipping and then next time I'm out will take the prop pff and inspect if it has a key or not in the prop. I still have some whooshing noises at about 2KW but I think they related to the water being pulled across the boat while at anchor and not an issue. I don't hear this while moving, only at anchor.
Again thanks!
Dan
