Mac how long have you been using the prop? If it is new to you then it could be the wrong pitch. However if you have been using it for a while with no problems then it sounds like a hub to me.

I would only question it because of the time it is taking to go. I have spun four of them through my boating years (two on my V20). Usually they go completely after 3-5 take-offs, leaving you with an idle speed.

Try another prop, borrow one for an hour if you need to.
Don't think it would be the trim tabs at all.