Could I use this?

[Scottydawg]

I have a 12' Jonboat (Aluminum). Can I use a 25hp motor on it or will that be way to big and not safe?

Thanks in advance.

 

[RotaryRacer]

Re: Could I use this?

I would guess that the boat is probably only rated for 10hp. If it doesn't have a capacity plate I wouldn't go over 10hp. Otherwise, go by what is on the capacity plate.

 

[scoutabout]

Re: Could I use this?

Yeah -- I think you'd find that way too much weight and power. My 14 foot tinny is rated for 17.5 (yuh -- you read it right. ). I put a 20 on it for a couple minutes once and it wasn't good...

 

[Scottydawg]

Re: Could I use this?

Thanks for the info. The reason I was wondering is a friend gave me a 25 and I was contemplating on whether to sell it and by one smaller or keep it.

 

[Scottydawg]

Re: Could I use this?

Thanks for the answer. The reason I was wondering is a friend gave me a 25 and I was contemplating on whether to sell it and by one smaller or keep it.

 

[scoutabout]

Re: Could I use this?

Looks like you have a couple of options. Find a motor for the boat you have or find a boat for the motor you have.

Seriously, if you expect to carry much more than you on a regular basis that 12 footer will seem small pretty quick. I see you have a much bigger boat in your sig so perhaps this jon boat doesn't need to haul the family. You still have water and weather considerations where you plan to do most of your boating and might want something with higher sides a bit more heft.
If the 12 footer is indeed right for you, though, you could probably get a pretty good dollar for the 25 and put it towards a 9.9 which would do just fine on that boat.

 

[Chris1956]

Re: Could I use this?

I had a 12 Jon boat(36" beam). A 5HP motor pushed it OK. A 7.5HP motor lifted the bow so much I was concerned I would backflip. I would think a 25HP motor would be way too much power.

 

[jay_merrill]

Re: Could I use this?

Using the 25hp motor with that boat would not be a good idea. Its probably rated for about 6 - 8 horse power, unless it is exceptionally wide for a 12' jon.

Measure the width of the boat at the bottom and let us know what the measurement is. That will give us a better ability to make an educated guess as to what you allowable HP rating is.

If you can tell us the manufacturer name too, one of us might even be able to find the actual rating on the net somewhere.

 

[Scottydawg]

Re: Could I use this?

The bottom of the transom is 32". The top is 40" and the depth is 14". May be that helps?

 

[arks]

Re: Could I use this?

The bottom of the transom is 32". The top is 40" and the depth is 14". May be that helps?

Well, for comparison, I have a 14' "Big Jon" which has taller sides and is 48" wide at the floor. It's rated for 25HP maximum and is what I use.
I think a 25 is too much for a 12 footer.

 

[jay_merrill]

Re: Could I use this?

The beam of a flat bottom jon boat is typically described in terms of the bottom width - your's would be described in a sales brochure, etc., as a 12x32. This gives me an understanding of just what you have.

Putting a 25hp motor on your boat would result in overpowering it by a factor of at least 2.5. Not a good idea.

 

[Scottydawg]

Re: Could I use this?

Thank you all for so much response so quickly. It was very helpful.