How big of a motor for Jon Boat?

[ChalupaCabras]

How big of an outboard would be needed for a 20 foot, 760lb jon boat? I wouldn't be looking for speed, just enough to get around with. A boat like that is usually rated for 60+ horsepower, but would 20 be enough?

 

[360]

I would put at LEAST a 40 on it.

 

[rhart]

A 20 HP even pitched way down may not get it to plane out. Especially by the time you ad gear and beer.
If you already have the 20, you may give it a try with like a 10 pitch.

 

[bass pro]

a 20 will push it but will be sorta slow. it wont be enough to lift the front. i would suggest at least a 50

 

[thecanuck]

I'd say a 40-50 at least... I had a 16' Jon that I used as a duck boat and it had a 20 when I first got it and with gear, guys, dog and everything it struggled to get on plane. Depending on where you're going that might struggle in any fast current...

 

[southern.in.guy]

Get the biggest one you can get if its rated for a 60 thats what id get or something close to or it will be hard on motor

 

[cosermann]

It varies a bit with the hull design (and how motor hp is measured), but somewhere around 70 lb. of 'boat' / hp of motor should, on average, get you up on a plane (this 'boat' is all up loaded weight including, boat, motor, people, equipment, etc.). More hp than that makes you go faster. Less hp and you may be tooling around at hull speed.

Therefore, if your total, all up weight is 760, and the boat is flat bottomed and hard chined, a 20 hp motor should get you up on a plane as that would be only 30 lb. of rig/hp (well under 70). But, things tend to weigh more than people think, or they add stuff as they go along, and a few hundred pounds later things may not work so well.

I understand wanting a smaller motor for expense and fuel economy reasons.

I'd suggest taking your rig to a truck scale and actually weighing it (subtracting the weight of your tow vehicle and trailer of course). Should be able to find a scale if you look around at the truck stops and/or farm co-ops. You might be surprised how much the boat and associated stuff (don't forget to account for passengers) actually weighs.

 

[OutaAmmo]

boat motor

I have a 75 Yamaha 4 stroke on my bowfishing 20 ft flat bottom plate boat. Had a 40 Yamaha on it and it wasn't enough hp. It will run about 28 mph and I get 5 miles to the gallon. I have seen similar boats with uo to 200 hp motors for those that like to fast. Get the biggest you can aford, you won't be sorry.

 

[hickuleas]

Jon Boats

Are you mainly running rivers if so going against to current makes a difference. You want enough power to get you out of a bad situation. I run a 16' jon with a mercury 90 hp which is 65 jet hp and that isn't enough for me. If you will be in shallows take a look at jet motors. Go to a boat dealership they could probably help. Get the rated horse power for boat or you will regret it.

 

[rimfire_crazed]

75% of Maximum hull rated HP for bare minimum performance. If you go less than that you may not get the boat to plane and you'll be guzzling gas, throwing major wakes, and generally not having any fun.

 

[tuckdog]

I would put whatever your budget will allow. Of course the bigger the better!!!