New To Tin Boats Need help with Stabilization.

Sharkbite · Mar 11, 2009

Hey guys I'm John from NJ. I have a 12' Starcraft. Its pushed by a 3 HP Mercury. My concern is when I take turn and go back to striaght the vessel wobbles back and forth. I am thinking about using PVC capped off and mounting it to the side a inch obove the water line.

Any one do this before? I am opean to anything thanx

Waterwings · Mar 11, 2009

Welcome Aboard! 8)

How fast are you going when you take the turns, and how narrow is the boat?

ben2go · Mar 11, 2009

:WELCOME:

Sharkbite · Mar 11, 2009

Waterwings said:
Welcome Aboard! 8)

How fast are you going when you take the turns, and how narrow is the boat?

I haven't measured the beam but it around 3'. I'll be goin bout half throttle when it starts to have problem.

ben2go · Mar 11, 2009

Sounds like the outboard may be loose in it's mount or the transom mount is loose.Is this a V hull with a flat floor at the transom?It may have a hooked hull.Make sure the bottom of the hull is flat and straight where it meets the transom.This is the area that the hull rides on when it's up on plane.

Sharkbite · Mar 12, 2009

here is a pic of the boat bro

russ010 · Mar 12, 2009

hopefully bassboy1 can input on this - I think he had a jon similar to that one

Sharkbite · Mar 12, 2009

the transom

Ouachita · Mar 12, 2009

Are you sitting up on that pedestal when you are running the outboard? If so, that is more than likely contributing to your wobble. That is a pretty high center of gravity for that narrow of a boat.

bassboy1 · Mar 12, 2009

Ouachita said:
Are you sitting up on that pedestal when you are running the outboard? If so, that is more than likely contributing to your wobble. That is a pretty high center of gravity for that narrow of a boat.

Those are my thoughts exactly.
I had both a 12 foot Grumman, and a 12 foot Sea King, powered by a 4 horse Evinrude. The Grumman was 5 inches wide (at widest point), and the Sea King was about 48, at the absolute wides point. We had a swivel seat mounted straight atop the bench on both of them. Never any of the problems you speak of. My guess is your pedestals are causing trouble.

grizzly · Mar 12, 2009

nice boat, i'd deck it out. that would add weight and lower your center of gravity. i had the same problem and the decking really made a difference in my 12 footer. i only have my rear seat on a swivel, and it works for me. if you really want that height you could use a pin pedestal that you can pull easily when you're running so you can sit lower. my boat is the "12' smokercraft shallow vee", dont know how to link to it.

Anthony Sisk · Mar 12, 2009

My buddy has a boat identical to that;with9.9 tohatsu and it is as stable as anything ive been on.He cut the bench's out and put a deck all the way across.It made the seats have a lower center of gravity.

redbug · Mar 12, 2009

i also think if you are sitting on the seats while running that is causing your wobble. most boats say d not sit while under power

Waterwings · Mar 12, 2009

bassboy1 said:
Ouachita said:

Are you sitting up on that pedestal when you are running the outboard? If so, that is more than likely contributing to your wobble. That is a pretty high center of gravity for that narrow of a boat.

Click to expand...

Those are my thoughts exactly.
I had both a 12 foot Grumman, and a 12 foot Sea King, powered by a 4 horse Evinrude. The Grumman was 5 inches wide (at widest point), and the Sea King was about 48, at the absolute wides point. We had a swivel seat mounted straight atop the bench on both of them. Never any of the problems you speak of. My guess is your pedestals are causing trouble.

Exactly my thoughts also when I saw the pics. Concur 100% with the comments above.

ben2go · Mar 12, 2009

Waterwings said:
bassboy1 said:

Ouachita said:

Are you sitting up on that pedestal when you are running the outboard? If so, that is more than likely contributing to your wobble. That is a pretty high center of gravity for that narrow of a boat.

Click to expand...

Those are my thoughts exactly.
I had both a 12 foot Grumman, and a 12 foot Sea King, powered by a 4 horse Evinrude. The Grumman was 5 inches wide (at widest point), and the Sea King was about 48, at the absolute wides point. We had a swivel seat mounted straight atop the bench on both of them. Never any of the problems you speak of. My guess is your pedestals are causing trouble.

Click to expand...

Exactly my thoughts also when I saw the pics. Concur 100% with the comments above.

I am in on this also.My other post is still valid but the seat height is most likely the wobbly culprit.I didn't have this info available to me when I made my first post.

Sharkbite · Mar 12, 2009

Dam really guys you think the seats are to high? That does make sence. Do they make lower petastools the the 7'' I have?

Sharkbite · Mar 12, 2009

grizzly said:
nice boat, i'd deck it out. that would add weight and lower your center of gravity. i had the same problem and the decking really made a difference in my 12 footer. i only have my rear seat on a swivel, and it works for me. if you really want that height you could use a pin pedestal that you can pull easily when you're running so you can sit lower. my boat is the "12' smokercraft shallow vee", dont know how to link to it.

You mean build a deck flush with the highest part of the boat? Then were do I put the seats? Could the seats still be on a patastool then? Can't I build some type of out riggers for it at all? What if I built a deck flush with the bench below the seats? I was thinking not the whole length of the boat but maybe from the front seat foward. Would it then be better? So by adding weight it increases stability?

Andy · Mar 12, 2009

I have a 12 foot Starcraft also. No problems with being stable. I would have to agree with others about the seat height causing the wobble.
As far as decks, you could do it several different ways. Personally on my boat, I thaught about doing a floor deck, just a few inches off the floor, leaving the bench seats where they are, putting pedistal mounts on the floor deck with long posts and still having the benches to sit on when using the outboard. You can go through all the boat mod threads and get some ideas to help ya out.
Another thing you might want to think about is adding some flotation under the bench seats. Something like this.
My deck plans is for the floor to be even with the bottom of the flotation boxes.

:beer:

Sharkbite · Mar 13, 2009

Andy said:
I have a 12 foot Starcraft also. No problems with being stable. I would have to agree with others about the seat height causing the wobble.
As far as decks, you could do it several different ways. Personally on my boat, I thaught about doing a floor deck, just a few inches off the floor, leaving the bench seats where they are, putting pedistal mounts on the floor deck with long posts and still having the benches to sit on when using the outboard. You can go through all the boat mod threads and get some ideas to help ya out.
Another thing you might want to think about is adding some flotation under the bench seats. Something like this.
My deck plans is for the floor to be even with the bottom of the flotation boxes.

:beer:

Yeah I hear ya I might try dropping the seats then and see how it runs . You know that ridge that runs along the sides of the boat. Well that if for putting in a floor if you wanted to install a floor on yours. FYI

Andy · Mar 13, 2009

Yeah, I thaught about decking at that point, but want to go lower. (more stable)
Thanks for the FYI though.

New To Tin Boats Need help with Stabilization.

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