I noticed a vibration while only trimming down this weekend. The RPM was around 4000 and the speed was around 40. It does not do it while going slower or while turning.

Engine 496HO w/ X drive

The first time (new hull) we had it out on the water I was backing into a friend's slip and had no idea there was a lift in the water that was not all the way down or even if it was set up to allow backing in. I was in neutral when I found out but when I bumped it forward to get away the engine stopped (which I DID NOT LIKE) and there is a very slight ding in the prop (23P). I am pulling the prop today to get fixed.

For what it is wroth, we had the boat out that weekend as well as the following week and did not notice or feel anything. It wasn't until the last outing this weekend that it was noticed.

Is there anything else I should look for?

I would check for a bent prop shaft

That is what I was afraid of.

Now I do not know if this is a stupid question. I am sure if was really bent I could see it while running it out of the water. But if it is a minor bend, is this something I could see with the naked eye?

She is in the shop and the prop is getting repaired and cupped. I will let you know what they say. Right now some are also thinking it may be the U-joints.