Suggestions about boat not getting on plane and prop protection

toclimbk2

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Sep 8, 2022
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I have a 16 x 3 foot wooden flat bottom jon boat weighing about 250 lbs.

I have a 6hp 4 stroke outboard that I use to motor up river so that I can float back down.

When I'm able to open the throttle a bit, the front end raises so I'm not getting on plane. Some people that have notice me, offered the suggestion to put more weight in the front.

It's not like my 6hp will get the boat going to fast with myself and gear and at times another adult.

I was thinking of getting a hydrofoil but would that work in my case?

Also, I primarily boat in rocky rivers where I often have to get through a foot of water or less so I was thinking of some type of prop guard like below. Thoughts?

https://macs-prop-savers.myshopify.com/collections/river-runner
or
https://www.driftboatparts.com/product-p/smpg35.htm
 

dingbat

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Joined
Nov 20, 2001
Messages
14,252
I have a 16 x 3 foot wooden flat bottom jon boat weighing about 250 lbs.

I have a 6hp 4 stroke outboard that I use to motor up river so that I can float back down.

When I'm able to open the throttle a bit, the front end raises so I'm not getting on plane. Some people that have notice me, offered the suggestion to put more weight in the front.

It's not like my 6hp will get the boat going to fast with myself and gear and at times another adult.

I was thinking of getting a hydrofoil but would that work in my case?

Also, I primarily boat in rocky rivers where I often have to get through a foot of water or less so I was thinking of some type of prop guard like below. Thoughts?

https://macs-prop-savers.myshopify.com/collections/river-runner
or
https://www.driftboatparts.com/product-p/smpg35.htm
A John boat is not designed to plane.

Most around here literally use a “pitch fork”

1662672850941.jpeg
 

Bondo

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Apr 17, 2002
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Ayuh,.... Welcome Aboard,..... As dingbat says, it ain't a planin' hull,....

I suggest a jet-drive motor, 'n move the gas tank to the bow,.....
 

airshot

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Jul 22, 2008
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Make sure you are trimmed all the way in and put whatever you have in the front, dont think a 6 hp will ever get you up and runnin flat !!
 

toclimbk2

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Sep 8, 2022
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Thanks for the responses. This is my first boat and outboard experience.

I would love a jet engine but the most I can probably put on the transom is a 9hp and they don't make jets that small.

Seems the only thing to do is try to put more weight up front which would be tough to do if I'm by myself. Guess I could get some cinder blocks or something to put up there.
 

dingbat

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Nov 20, 2001
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Seems the only thing to do is try to put more weight up front which would be tough to do if I'm by myself. Guess I could get some cinder blocks or something to put up there.
Adding weight is self defeating…

A John boat is simply a 4 sided box flipped upside down. It will plane and is speed limited in its design.

Adding weight increases drag which requires even more HP to go a given speed. Add enough weight and it will run flatter simply because you run out of HP to attain the speed required to push the bow up

If you want to go faster you need a different hull design.
 

toclimbk2

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It's not so much about wanting to go faster but to lower the bow.
I wonder if one of those hydrofoil tails would help.
 

dingbat

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Nov 20, 2001
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It's not so much about wanting to go faster but to lower the bow.
I wonder if one of those hydrofoil tails would help.
Your typical 16' john boat is rated 25 - 35 HP......your dealing with 6 HP.

In theory, a whale tail would raise the transom, flattening the attack angle (to an extent), but a whale tail needs speed to generate lift.

The conundrum you face is that increasing your speed to generate lift also increases the size of the wave your trying to overcome.

As someone who has spent a considerable amount of time chugging along in heavy, under powered, crabbing skiffs, my advise would be......keep the cooler well stocked and within easy reach of the tiller. Find a cruising speed your comfortable with, reach in and grab a cold one, and sit back and enjoy the ride. ;)
 
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QBhoy

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Mar 10, 2016
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6,995
Your engine is simply not man enough. Get yourself a good old 2 cylinder Yamaha or merc 2 stroke. One that’s a big as you can manage to easily manage. Even an 8-15hp 2 stroke will see a huge difference over what you have. No doubt.
 

Texasmark

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Dec 20, 2005
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My grand daddy had just such a boat, planked flat bottom, sealed with lead and Okum (spelling) cord, powered by a 10 hp Johnson back in the mid 1950's. On occasions when I visited, I would move to the bow seat and the boat would barely plane. When coming home in the afternoons, the wind, always from astern, usually was up pretty good and the boat would do the ride and dive thing and the waves were running faster than the boat......to give you an idea as to what to expect with your available horsepower.

For the times he fished alone, he rigged a lever, operated from the center seat whereby he could steer from that seat and having moved his weight forward could plane....barely he said.
 

jimmbo

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May 24, 2004
Messages
11,076
When I was teenager, could get a 10ft car topper to plane with a 5 1/2, but certainly couldn't plane the 12ft car topper
A non-planing hull, aka Displacement Hull, takes very little power to push up to its' critical speed, once there, a 10 fold power increase isn't going to do much, except become dangerous
 
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