Re: Does new engine turn you off.
Not always.
If the boat was sold originally underpowered then absolutely no, we have all seen the 24'-25' bowrider with a 5.0L motor, and that is underpowered for most buyers, if that same boat was cared for properly over its lifetime and is in good or great shape, it is the perfect boat for a repower, plus it would make it more valuable on the US market.
But I agree with you that the majority of time, it certainly causes me to wonder what the owner did wrong, and what else could the owner have done.
But the fact is that most of the time US owners are all about horsepower, those that look for fuel efficient boats are very much in the minority, add to that the fact that bigger motors in bigger boats can be more fuel efficient then smaller motors in the same boat and uneducated new buyers with lots of money and you have a perfect storm for underpowered large boats.
So I guess for me the answer is Yes and No?!