Boat unstable on plane

[.Bennett]

I have an '01 Key Largo 172 CC powered by a '95 Evinrude 88SPL (90HP). I'm having a stability issue when the boat is on plane and the water is anything but calm. There is a small bay (mile wide) on the river I fish and when crossing it with any wind, the boat jerks side-to-side abruptly when going across (perpendicular) the small swells. I use the term "swells" lightly because they aren't even white-caps and are 6" at absolute most.

It is very difficult and somewhat scary to drive in these very minor conditions because the boat jerks/turns itself so abruptly that I've nearly lost passengers. I've varied speeds between 18-30mph and that doesn't help. Only coming off plane stabilizes it.

What could be the problem here? Seems like the steering might be too free to allow this to happen, but I really don't know. I've tried various trim angles as well with no luck (no trim tabs though). Help me out y'all!!

Thanks!

 

[BigBoatinOkie]

Re: Boat unstable on plane

Wow. I wish I could help out. That sounds scary, somethin aint right. Good luck.

 

[njrextreme]

Re: Boat unstable on plane

Do you have tilt/trim? It sounds like you have to much boat out of the water. Trim it to drop the front down some. Or if the front is all the way down, trim it up.

 

[dockwrecker]

Re: Boat unstable on plane

Tabs baby tabs! The Smart tabs seem to be the ticket for fixing this issue for boats your size, I haven't heard a comment here yet that was negative about them.

 

[capt sam]

Re: Boat unstable on plane

that boat is pretty light and when you power across the waves you're going to go side to side, slow down some, not all boats can fly thru a chop, work with what you have.

 

[Bifflefan]

Re: Boat unstable on plane

My old 16' used to do something simular in that it would flop one one side or the other after it got on plane.
I thought about using smart tabs, but opted for a new boat.
Id give the smart tabs a try and see how they do.
Or you can do like i did and get a new boat.

P.S. mine scared the he** out of me a couple times.

 

[Bondo]

Re: Boat unstable on plane

Ayuh,.... Learn how to drive a Boat....

A Straight line to your destination is Not always the Best way to get there....

 

[109jb]

Re: Boat unstable on plane

Trim it in a little to help.

 

[Lrider]

Re: Boat unstable on plane

My old 16' used to do something similar in that it would flop one one side or the other after it got on plane.
I thought about using smart tabs, but opted for a new boat.

Excellent Option, wish I woulda thought of that

 

[.Bennett]

Re: Boat unstable on plane

Ayuh,.... Learn how to drive a Boat....

A Straight line to your destination is Not always the Best way to get there....

lol I realize that. And unless you have a computer on your boat, you spend way more time posting than you do on the water. So feel free to get off your high horse at any time.

Like I've mentioned, I've played with the tilt/trim a fair amount and can't seem to get it. I'm not trying to go warp speed here, 18mph isn't unreasonable IMO and seems far too slow to be having these issues.

I was guessing tabs would be my next step but I figured if there was a cheaper/easier fix, I'd try that first.

Thanks for the replies guys (most of you). And lol at getting a new boat to solve the problem.....if only

 

[ziggy]

Re: Boat unstable on plane

lol I realize that. And unless you have a computer on your boat, you spend way more time posting than you do on the water. So feel free to get off your high horse at any time.

i don't think he's on a high horse. my boat had/has some less than desirable handling anomalies. it took me a couple years to learn how my boat handled. when it does things don't want it to do, i try not to put it in a condition that causes the problem. whatever the condition, whatever it takes to cure it. slow down. don't drive perpendicular to the waves. to me, that's one of the the more dangerous ways to take waves too.

 

[.Bennett]

Re: Boat unstable on plane

whatever the condition, whatever it takes to cure it. slow down. don't drive perpendicular to the waves. to me, that's one of the the more dangerous ways to take waves too.

Yeah that's what I've been doing. I'm certainly not trying to get in another situation that's dangerous at all. I know how to avoid it and how to get safely to and from my fishing spots, I was just curious if this was normal because it doesn't seem so to me.

This bay is a very high traffic area and most boats go flying thru there without apparent issue. Every setup/boat is unique, I know, but it seems odd to me so I thought I'd see what y'all thought.

Nauticus is the Smart Tab maker everyone is referring to, correct?

 

[URDADDY]

Re: Boat unstable on plane

Learn to drive a boat may have been a little rough... I grew up on a lake running boats in some very rough water and since I learned there never really had any issues. After 15+ years off the water I recently got back. And first couple of runs out I also had a little trouble dealing with waves. Like a bike it came back pretty quick. Not having much trouble now. So I would say give it a little time, try hitting the waves a little different until you see what works for your boat. Every boat is different and sometimes it takes a little time to learn the new boat. (no matter how "godlike" ) some think they are on here.

 

[4JawChuck]

Re: Boat unstable on plane

18mph on 6" waves, and people are in danger of falling out of the boat?

Something is seriously wrong, take it in or have someone experienced ride with you and drive the boat. Is the motor tight on the transom? Does the steering have a lot of play? Have you ever owned a boat before?

Sounds like an accident waiting to happen.

Is this your boat?

 

[capt sam]

Re: Boat unstable on plane

18mph can be way too fast depending on how the chop is, especially in a light weight boat. Don't try and force it, it's how things get broken, try running at an angle, people are always talking about running 40mph thru 4' waves here in smaller boats, I've never seen it done in a safe manner.

 

[kenmyfam]

Re: Boat unstable on plane

lol I realize that. And unless you have a computer on your boat, you spend way more time posting than you do on the water. So feel free to get off your high horse at any time.

Believe it or not, every response has been trying to help you and the one you are referring to here was actually the best advice and easiest to try. Compare it to driving a high sided vehicle in a strong side wind if you can as opposed to a head or tail wind.
You asked the question, people responded with their thoughts and experiences. If you can not be civil in return then don't respond at all.
My 2 cents.

 

[JB]

Re: Boat unstable on plane

"lol I realize that. And unless you have a computer on your boat, you spend way more time posting than you do on the water. So feel free to get off your high horse at any time."

You have probably figured out from the responses of other members that this is not iboats style. Please make an effort to be more courteous. The comments you were responding to may have been more direct that you would have preferred, but they were bull's eye accurate.

 

[marcortez]

Re: Boat unstable on plane

"lol I realize that. And unless you have a computer on your boat, you spend way more time posting than you do on the water. So feel free to get off your high horse at any time."

You have probably figured out from the responses of other members that this is not iboats style. Please make an effort to be more courteous. The comments you were responding to may have been more direct that you would have preferred, but they were bull's eye accurate.

As long as your touting courtesy among the ranks on here, Mr Bond-O should be at the top of your "courtesy watch"
He responds with a grunting "AYUH" and then condescendly, tells the OP to learn to drive his boat.

Although that may be the solution, an explanation as to why it's a solution, would, in my opinion, be a "courteous" response.

 

[tx1961whaler]

Re: Boat unstable on plane

18mph on 6" waves, and people are in danger of falling out of the boat?

Something is seriously wrong, take it in or have someone experienced ride with you and drive the boat. Is the motor tight on the transom? Does the steering have a lot of play? Have you ever owned a boat before?

^^^ Agree with 4Jaw on bringing someone else more experienced for a ride and drive to see if there is an actual problem here. The performance could be within the normal expected behavior. Light boats can slam around quite a bit when on plane in chop and it's normal.
Or your motor could be ready to fall off. Kind of hard to tell over the internet.

 

[Bondo]

Re: Boat unstable on plane

Quote:
Originally Posted by JB
"lol I realize that. And unless you have a computer on your boat, you spend way more time posting than you do on the water. So feel free to get off your high horse at any time."

You have probably figured out from the responses of other members that this is not iboats style. Please make an effort to be more courteous. The comments you were responding to may have been more direct that you would have preferred, but they were bull's eye accurate.
----------------------------------------------------------------------------------

As long as your touting courtesy among the ranks on here, Mr Bond-O should be at the top of your "courtesy watch"
He responds with a grunting "AYUH" and then condescendly, tells the OP to learn to drive his boat.

Although that may be the solution, an explanation as to why it's a solution, would, in my opinion, be a "courteous" response.

Ayuh,.... I'm a single digit typist,... That don't like Horses....
If you want a Warm Fuzzy feelin', rather than Rock Solid Advice,....
I won't post to your questions....
Short to the point answers are the Best you'll get from Myself,...

I also won't argue that I spend WAY too much time on iboats, trying to Help, sometimes Unappreciative posters....
But,...
I was born with a 9/16ths" wrench in My hand,+ have been boatin' for nearly a 1/2 Century....
If you find My posts Offensive, I believe there's an Ignore option in your user CP....
Use it...

I'm done here........

Btw,..... Thank you to My Friends who've defended My response.....