h.p. for 20 ft jon boat

My cousin has ordered a 20 ft Xpress jon boat. It is rated at 115hp with console. The boat is open in the middle but plans are to build a livewell. My question is does a 115 sound like to much? And how fast do you think it would run on the water? Thanks,Brian.

Well, to give you an idea here, years ago we ran a 24' Carolina Skiff (flat bottom) with a 1989 Johnson 40hp. Boat planed off immediately but naturally wasn't a speed demon at around 30-32mph. That boat was used as a duck hunting boat until we finally realized it took darn near a forest of palmetto leaves to camo it. It would carry a ton in it an not lose performance. In your case the boat would move respectfully with a 70hp on up as it is either a flat bottom or almost flat which is very efficient for what you want it for.

What I've heard is you want 70% of the rated hp as the minimum. That would be 80hp.

Thanks for the input. My cousin already bought an older bass boat for the motor a 115 Johnson.I told him I thought around 85hp would be plenty. We,re going to use it for catfishing on the Tennessee river. Thats one reason he got such a big boat because some of the boats that pass you while you,re anchored are huge. I guess if he runs it sparingley it wont be to scary fast. Thanks,Brian.

Well my advice is hold on tight. It should push that boat hard.

Bufford

I had a 22' seaark bought new in 97 put a 115 merc on it and it ran about 44mph. When i first got it i had a new 55 hp Yamaha it got on plane slow and it topped out about 28. I hit less rocks with the 115 because it was on plane instantly no stern squat