Loss of hole shot and performance plus vibration trouble

[jdklein001]

There are a few things going on. I suspect related but perhaps not.
This is on a 28’ regal express cruiser with twin merc 4.3 with alpha one gen one drives. Motors run well. Drives got me impellers and oil in the spring.

1. On the port side when the drive is trimmed all the way down I get a vibration when I’m under way. If I trim it up a bit it goes away. It goes away equally if I trim both sides up together or just the port and leave the other alone. The vibration seems to go away regardless up around cruising speed but perhaps I just can feel it any more.
2. Recently the water was low in the river I dock in my prop hit mud and stalled the engine, I can’t remember which side it was unfortunately. It was vibrating before this happened.
3. Some of the time (especially today) when I accelerate from headway speed the stern just sinks down and the engines rev but I just drag ass and can build up speed.
This was not the case last year or for my first real run this year. It seems to be getting worse although it seems to be somewhat intermittent (I’ll try again in the morning and perhaps it will have stopped being intermittent).
4. My trim tabs have stopped working in a bow down position.

Any thoughts about what’s happening? The boat stays in the water, I’ll get in there and do what I can. I hope to not haul it.

 

[QBhoy]

Hi. Hard to say not knowing what’s left of the props. But one of two things or both may be occurring.

1 you’ve spun the prop hub or hubs

2 you have lost that much of the prop it’s just not working well. For certain even a tiny sink in your prop will cause at least vibration and a loss in performance. They are precision cut and balanced things. As with most every rotational piece of machinery.

 

[jdklein001]

I’m jumping in the drink in the morning to have a look at the condition and see it it’s spun. I believe that would be a likely cause of both conditions