Prop slip??

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.