any tips for planing a 14ft jon boat?

[DJ Grimes]

have a 14 foot fiberglass john boat v hull design with 9.5 evinrude sportwin gas motor
for some reason planing is a head ache trim up nose raises an stays trim down ribs on the nose trim half tries but no sucess anyone got any tips or trick

 

[Grub54891]

Re: any tips for planing a 14ft jon boat?

Throw some weight up front,the motor probably cant get enough speed to get er over the hump..

 

[JimS123]

Re: any tips for planing a 14ft jon boat?

That long unpunctuated sentence was hard to decipher, but if I understand you correctly you probably have the wrong pitch prop. An engine rpm study would help in the diagnosis.

Short of that, don't add weight because that will make it run even slower. Just move around the weight you already have, with the engine trimmed so the anti-vent plate is parallell with the bottom.

But before you do anything, be sure the engine is running on both cylinders.

 

[tomhath]

Re: any tips for planing a 14ft jon boat?

Make sure motor is firing on both cylinders. It can run pretty well on just one.

 

[Solittle]

Re: any tips for planing a 14ft jon boat?

A 9.9 will plane two people in a 12' aluminum. A 9.5 in a fiberglass 14'er - maybe not no matter what you do.

 

[fishrdan]

Re: any tips for planing a 14ft jon boat?

have a 14 foot fiberglass john boat v hull design

Is it a jon boat (flat bottom), or a V-hull, or a modified jon with the V up front and the back flat? Pics if you have them... A jon boat will plane much easier than a V-hull, so we need to know exactly what you have.

I agree with the above posts, weight forward, check that the outboard is performing as it should.

I'm going to throw out the "hydro-foil" thing... I have a Sting Ray Jr. on my 14' aluminum jon boat and it works very well to get the boat on plane. I wouldn't run the boat without it.

 

[pafree]

Re: any tips for planing a 14ft jon boat?

not sure what year motor you have but my 1969 9.5 is having simular problems and i found that the outside metal part of the prop is slipping on the rubber center hub.

 

[kfa4303]

Re: any tips for planing a 14ft jon boat?

One trick is to make a tiller extender out of a length of PVC. Simply take a piece of PVC, cut a few slits in one end and slip it over the stock tiller and secure with a couple pipe clamps. It will allow you to sit, stand and shift your weight around as needed and only costs about $5. Of course, they make fancy carbon fiber and aluminum versions, but that would be overkill. You can also add some fixed/adjustable trim tabs on the stern as well.

 

[V153]

Re: any tips for planing a 14ft jon boat?

How heavy is the hull? Is it waterlogged?

Tasking a 9.5 with planing a 14' FG boat is asking a lot imo. Particularly with any amount of load onboard. Think you'd be much better off with a 30 - 40 HP motor.

 

[metriccrescentwrench]

Re: any tips for planing a 14ft jon boat?

....
Tasking a 9.5 with planing a 14' FG boat is asking a lot imo. Particularly with any amount of load onboard. Think you'd be much better off with a 30 - 40 HP motor.

I was thinking the same thing. Many many years ago my family had a 14 ft. aluminum boat (rated for 25 hp) with just a Johnson 7.5 and while it wasn't any speed demon it did ok with just me. Throw in a couple of adults and it took me quite a while to coax it to plane. I'm thinking a fiberglass hull would be a good bit heavier than aluminum, and probably getting to the point of being extremely marginal with a 9.5.

But definitely make sure the engine's running on both cylinders, check for the prop hub slipping, etc. just to rule out those possibilities.

 

[Home Cookin']

Re: any tips for planing a 14ft jon boat?

there are 14' fiberglass hulls that are just a skin like an aluminum and there are solid core like whaler and there are deckover bilge like MFG (I think they made them that small; I remember 15's). I think it was the Sears Gamefisher we had that was just a skin--very light.

There's a skill to standing up and putting your weight forward until you plane, kinda like getting up on a slalom ski and almost as tricky for non-boaters. the tiller extender helps tremendously--as does putting the gas tank and cooler forward. I never used a battery with a motor under 25.

 

[V153]

Re: any tips for planing a 14ft jon boat?

I think it was the Sears Gamefisher we had that was just a skin--very light

Believe those lil Gamefishers were plastic, not fiberglass.

Personally I don't think you can build a fiberglass jon boat any lighter than an aluminum one. 'Less'n ya spend alotta money'n make it outa carbon fiber, composite, etc.

Fwiw as a kid I had a 8' alum jon boat, 'overpowered' with a 6hp Evinrude. Think it was rated for like 2, but the old man beefed up the transom a lil. Fastest jon boat in Keystone Point. Me'n my lil brother could pull each other on tandem ski's behind it. No BS. Well, we were like 8 & 9 at the time ...

 

[Home Cookin']

Re: any tips for planing a 14ft jon boat?

Believe those lil Gamefishers were plastic, not fiberglass.

Personally I don't think you can build a fiberglass jon boat any lighter than an aluminum one. 'Less'n ya spend alotta money'n make it outa carbon fiber, composite, etc.

...

You're right but same idea.

 

[jhenschen]

Re: any tips for planing a 14ft jon boat?

I have a similar problem. I have a 10hp Honda with a 14ft aluminum flat bottom. My issue is that I'm a big guy - 6'3 about 320lbs - and sitting in the boat is fine, but start that engine and it raises so high that I can't even come close to seeing over it. I've been looking in the Dole-fin hydrofoil options and it seems like that's just a hit or miss option and I don't know if I want to invest the time and money into that if there's a little chance it will work. Other say trim tabs are the way to go. However, looking at how much those cost, those would be the most expensive thing on the boat if I went that route.

My brother has a metal fab shop (with drop/scrap aluminum plate I could have for free) so I could take the boat there and maybe weld on some bent pieces of aluminum plate. I don't know... thoughts on cheap ways to fix with considering I have access to a metal fab shop?

Thanks!

 

[kahuna123]

Re: any tips for planing a 14ft jon boat?

I have a 40 year 14ft v-hull gamefisher style boat. I replaced the transom. I weigh 230 and my son is 120. With my yamaha 15 it screams.

 

[JimS123]

Re: any tips for planing a 14ft jon boat?

I have a similar problem. I have a 10hp Honda with a 14ft aluminum flat bottom. My issue is that I'm a big guy - 6'3 about 320lbs - and sitting in the boat is fine, but start that engine and it raises so high that I can't even come close to seeing over it. I've been looking in the Dole-fin hydrofoil options and it seems like that's just a hit or miss option and I don't know if I want to invest the time and money into that if there's a little chance it will work. Other say trim tabs are the way to go. However, looking at how much those cost, those would be the most expensive thing on the boat if I went that route.

My brother has a metal fab shop (with drop/scrap aluminum plate I could have for free) so I could take the boat there and maybe weld on some bent pieces of aluminum plate. I don't know... thoughts on cheap ways to fix with considering I have access to a metal fab shop?

Thanks!

In my opinion your type of hull is not suitable for trim tabs because of the design of your transom. They belong on bigger fiberglass boats.

The "hit or miss" reasoning is due to the naysayers that haven't done it right.

Yours is a classic example of what the DoelFin was invented for.

 

[limitout]

Re: any tips for planing a 14ft jon boat?

on my 14ft flat I had a 15hp Yamaha and it would only plane with just me in it, it struggled to do that and adding another person it would barely just plane off if the other person went to the bow after we started off (not before)

with 3 people it was like a barge and never even tried to plane off

in my opinion if you want to plane off you need nothing less then a 15hp and better to have a 20hp +

if a motor change isn't feasible then just settle for the 10-15mph you get pushing it thru the water

 

[JimS123]

Re: any tips for planing a 14ft jon boat?

on my 14ft flat I had a 15hp Yamaha and it would only plane with just me in it, it struggled to do that and adding another person it would barely just plane off if the other person went to the bow after we started off (not before)

with 3 people it was like a barge and never even tried to plane off

in my opinion if you want to plane off you need nothing less then a 15hp and better to have a 20hp +

if a motor change isn't feasible then just settle for the 10-15mph you get pushing it thru the water

Boy, lots of tag-a-longs on this thread.....LOL.

My old 14' flat would plane like a banshee with FOUR aboard. Obvioulsy, you are totally propped wrong! Add a fin to that and you'd fly.....LOL.

If you can't get a 14 to plane with a 15 you got some work to do!