Outboard HP for boat size

Looking at a 21ft 1997 Cajun ski and fish boat hull. It's rated up to 200hp but can't find a minimum hp rating like on my current boat. I have a really solid 80's Evinrude 115 hp that I could put on it but would that even work? Any information would be helpful, thanks.

It would be way under powered.

If it's rated for a 200 then the 115 would really be lacking for power. HP ratings are based on beam width and hull length while over all weight of the boat and motor will determine the performance. The closer to the maximum HP you go with the better off you'll be. A 21' boat with a 200 HP outboard would probably be a 60 MPH boat or maybe a bit better depending on the hull weight. A 115 HP would probably be lucky to push that boat at 30 MPH. Your hole shot will be terrible and it will take a while to plane out. I ran a 125 HP on an 18' fish n ski that would bump 50 MPH barely. Prop pitch is a big player but a motor that much bellow the maximum rating changing prop pitch will never get you where you want to be. Just my opinion!

Better listen to Pat! With so little power, you'd be plowing badly and never get the hull up and "dry running". When you took a ride and got drenched by all the spray blowing over into the boat (with crosswind component) you'd understand why it would be a "wet boat". Fuel consumption would likely be horrible also.

Thanks for the replies

That cajun is a very heavy hull, I'd wager in the 1,800 lb class.
With a 200 on it, they typically run mid 50's setup correctly.
On average 10 hp = 2 mph so you're really looking at best case scenario high 30's, which is just plowing water.

Go find the right sized boat to hang your motor on, that one isn't it.

Thanks Pat. It is a Cajun Travis Edition and just seen a post where you advised to stay away from Travis Edition boats. Sucks but don't wanna end up with a can of worms down the road. Still searching...

Worms? Yeah, stay away from anything travis.