HP needed to plane a 1436 jon boat?

[sutor623]

Hey fellas,

Got a 1436 jon boat. Weight tag calls for 625 persons, motor, gear. Had a 5hp, two guys, two batteries, two trolling motors, some fishing rods. Front deck is made with aluminum bracing and 3/4" ply top. With all of this the boat was weighed down to 625lbs, for sure. Got 6mph out of her. Could tell motor was really lugging. Maybe a prop pitch change is in order? Only issue is it is a small Tomos air cooled motor and parts are VERY hard to find.

Next trip out, I used a good friends 15hp outboard. We went flathead fishing, which forced me to put my 10 gallon bait tank (live bream) on board. Then the guy I took this time was maybe 50lbs heavier and HAD to bring his YETI loaded to the brim. Probably another 100lbs. there. I know its a big no-no, but the boat probably had 900lbs. on board. Still felt stable, and floated great, but did NOT want to plane out, even with the 15hp. Motor was bogging down for sure!!!!

So here is the big question. I have two boats. Other boat has a big 130hp and we can take her to the big water. This boat mainly fishes electric only lakes. Sometimes I take it to a lake that only allows 9.9hp engines. Sometimes I take it to another small gas lake, and other times I take it to the river, that is 3-4ft. deep and the chance of smacking a rock on plane is a very REAL concern. Without a jet boat, I probably wouldn't break plane in fear of smacking open a lower unit.

I have three choices here.

1.) Get a very small gas engine that will push me up and down the river without worrying about trolling battery power.

2.) Get a larger outboard (9.9-15hp) so that I can plane with a light load, and putter when I want to.

3.) Get a long tail mud motor kit and build a 10-15hp engine that can run in shallow water, but is a PITA all other times.........

 

[fhhuber]

25 hp will plane it with about 350 to 400 lb of people and gear. Not sure about heavier loaded.

As you add load you make it harder to get the boat up on plane. Also weight distribution can affect results.

A friend has a 1436 with a 25 4-stroke and that's about where we are when we take it out. It gets up on plane without any trouble.

 

[sutor623]

Thanks for the input.

I forgot to mention, the transom calls for a 15hp motor. I know 4 strokes are heavier and have less torque, so I would imagine a 2 stroke 15 would be optimal.

 

[sutor623]

Do you guys think there would be much difference in say a 2.5hp vs an 8hp if neither one will plane the boat? I have heard that displacement speed is displacement speed. Maybe you would just have some more torque for current etc.

 

[Scott Danforth]

no, at displacement speed, you wont see much difference between an 8hp and the 2.5hp.

My first thought is to get a bigger boat with a bit more capacity.

 

[sutor623]

no, at displacement speed, you wont see much difference between an 8hp and the 2.5hp.

My first thought is to get a bigger boat with a bit more capacity.

Thanks man, thats what I figured. Id like a bigger boat, but this one is set up great.

I actually have 2 boats. My other rig is a 20'er and I use it quite often to fish big water or hang with family/friends.

That being said, the reason I even got this one was to get into some tighter fishing areas, and electric only lakes/ponds. Just want some versatility with gas.

I have friends that let me borrow their motors but I don't want to break them. A mans fishin motor is dear to him!!

 

[fhhuber]

Or a stronger transom version of the 1436... My friend's is an Alumicraft, all welded and rated for the 25. Yes, there are some not rated for as much power due to not being as strong.

 

[sutor623]

I had a 1432 loaded down and with two people an old 9.5 sportwin would plane it out.

 

[preventec47]

Do the model numbers mean anything ..... like is the 1436 a sixteen foot long boat ?
and 1432 a twelve foot long boat ?

 

[Texasmark]

Back when i was a youngster I went to visit folks living near Holly Grove, Arkansas. Nearby was the White River. 90% of the boats I saw were just as you describe. The largest engine I saw on the trip was a black and silver Marlin (brand) 6 hp and it was on the same style boat with 3 folks, clipping right along. I could get my sponsor's boat of such description on plane with their alternate firing 3 hp Johnson twin.....if I moved forward momentarily to get it up.

 

[flyingscott]

Do the model numbers mean anything ..... like is the 1436 a sixteen foot long boat ?
and 1432 a twelve foot long boat ?

Both boats are 14' long one is 36" wide at it's widest point same with the 32" beam.

 

[sutor623]

no, at displacement speed, you wont see much difference between an 8hp and the 2.5hp.

My first thought is to get a bigger boat with a bit more capacity.

Well Scott, I went ahead and did it. I run skinny water a lot so I found me a good all-welded 1648 Polar Kraft with a 20hp Merc factory jet. (20hp out of the jet)

Motor and boat were in such great shape I just could not pass it up. Found a buyer for my jon boat in 2 days, and got this girl for a great price.

We like to keep it light up the rivers here. This little motor only weighs in at 125lbs. It is pullstart so no need for a starter motor and a battery. I also took the trolling motor and front battery off unless I will use it somewhere I actually need it.

She planed out great with a top speed of 18mph with the following load: Boat (330lbs.) motor (125lbs.) 2 batteries (100lbs.) trolling motor (25lbs.) cooler (10lbs.) two anchors (25lbs.) and two people (310lbs.) for a total weight of 925lbs. I'm not kidding, we were running in 6-8" of water with no issues at all.

Next time out I brought a bigger bud with me. He weighs 50lbs. more. Boat still planed out well, but I could tell if I had added maybe another 100lbs. she would not have been doing so well. The weight up front brought the bow down some and my jet spray was coming out of the water more than I would have liked. Maybe if I play with trim it will help.

Anyways, shes no speed demon, but this light little boat will hum up and down the rivers with not issues. Running the rapids is pretty fun. Simplicity is key here. Other boat is about as complex as it gets Here she is:

 

[garbageguy]

That's pretty cool! Thanks for sharing

 

[Scott Danforth]

cool.....so what your saying now its not the boat keeping you from getting fish..... LOL

 

[sutor623]

cool.....so what your saying now its not the boat keeping you from getting fish..... LOL

Thats right!!!

It would have costed me at least $700-1000 to get a good used 9.9-15hp engine around these parts. I had to shell out 2 grand on top of what I sold the other boat for, so I think I made out really well. Sometimes you just have to know when to give up on a boat and make a move!! Thanks guys!!