Welcome to the forum.
There are tons of posts on this very subject if you choose to peruse the pages and look through them.
You will get answers like mine in which I will tell you to go for it and never look back and you will get answers about adhering to the rated horsepower plate. Your choice. Probably also get the couple of usual answers about being stopped and checked. I have never had it happen nor have I ever known anyone to be checked for additional horsepower.
On almost every small boat I own I have, usually, double the rated horsepower or around it. Boat manufacturers are very conservative on ratings due to the sue happy society we live in.
The most fun boat I run with too much HP is my Gheenoe Classic. A 15'6" fiberglass canoe with a planing hull. Rated for 15hp. It has never seen that small of an engine. Currently has a 3-cyl. Johnson 25hp on it and has had a 3-cyl. Suzuki 30hp, Evinrude Speeditwin (22.5hp), Evinrude Speedifour (33.4HP 4-cyl) and will soon have a 3 cyl. 35hp on it as well as a vintage Johnson RDS-20 35hp on it. Runs great with them. Common sense prevails of course!
I run a 12 Alumacraft Model R with a Johnson 25Hp on it all the time as well although this boat is equipped with steering and controls.
