Boat has a 115 merc on it just not enough power for me lol its rated for a 150 but there isnt a weight diffrence in a 175 and a 150? Anyone have a little boat with big motor?

There are reasons there are max hp on boats. It is not just the weight of the motor.

Do NOT go over the rated power.

As long as the transom is structurally sound I wouldn't think there'd be an issue with it holding it. However, over rating a boat can be a bad thing as they won't allow you to insure it and the fact that if you're ever in an accident, your fault or not, they can come after you for negligence and possibly found at fault for the accident.  

Legally it's not worth the hassle.

You will be liable for any thing that happens while you are operating it.

You will not be able to insure it.

I wouldn't trailer it without insurance.