Bill:
Not sure what your point is!!
I agree with you that normally engine speed not an issue.
This situation is NOT normal! There is a problem somewhere.
Also, why are you saying the fins do not flop because of pressure bleed.
This suggests that they are normally in the flop mode when engine is stopped - simply not correct. Normal position is maintained when engine is stopped for extended period.
Was just trying help and do not want to get into pissing contest, so I am done here!
Geez, calm down. I'm not trying to have a pissing contest.
The OP never answered my questions directly so I'm still not sure exactly what is going on and when. We don't even know how old his system is or what upgrades he may or may not have.
Fins most certainly can/do move around when the engine is stopped if you don't have the self pinning type. I've seen it many, many times. In fact I've seen it on the boat I currently run. That is one of the reasons for the self centering feature at slow speeds. And it takes hydraulic pressure to keep them centered.
If they don't self pin and the system is off while manuvering the fins can move all around due to the force of the water pressure on them. In fact they can interfere with how your boat manuvers. And out of the water you can rotate them by hand in many cases. They might be stiff but they can be moved.
So I don't know what is normally in the OPs case.
The OP said, "In CENTER mode they are centered. When activated they rotate to one side. I thought I may have picked something up on the fins but the problem occurs when the boat is stopped. "
Does "stopped" mean engines stopped and no system pressure? Or just no motion thtough the water but the engine/s are on and the system has pressure? Do they only go over to one side when the boat is stopped but the engines are on and the system has pressure? Or any time the are set to active/on?
I don't know. Not having a complete picture of what is or is not going on and when makes it hard to give answers that are more then just shots in the dark don't you think?
If they go to center when set to center but move all the way to one side when set to active/on, I would think its not a seal issue.
It sounds more like a gyro or settings issue.