Boat leans to one side

[solar7647]

I am having an issue with my boat leaning to the left side when at WOT and the trim is all the way down. If I bring the trim up it centers but still leans a little to the left, but with trim down its real bad . Now I have a 1987 four winns sundowner, 3.7l merc, alpha 1 drive. 4 blade prop 14 1/2 inch diameter. Now I know its not the trim tab anode because there is none i have a flat plate, i dont think its prop torque because its leans to the left and the rotation of the prop is to the right. I dont think it is a weight problem becuase the boat is level when standing still or at no wake speeds. There dosent seem to be any issues with the hull ether. Now I do have a hydrofoil, it looks centered, my question is has any one else had this issue using a hydrofoil and it causing this problem? Also would a bent skag cause this, it looks a little off to the left. Or does any one have and suggestions, I am clean out of Ideas!!

Thanks a lot!

 

[cbavier]

Re: Boat leans to one side

I don't think the skeg would cause it to lean. I almost destroyed mine on rocks at an unfamiliar lake. It had no effect but I did have it removed and repaired. The main purpose of the skeg (bottom) is to protect the prop.

My first thought was soaked or wet foam but if it sets level when at idle or parked it's not that.
My second thought was the trim anode.
Third could be steering but I don't think that would cause it to list.
Fourth.
It has to be in your hydrofoil. Question is it spring loaded or fixed? If it's spring loaded then that could be the problem. The spring plate may not be coming up when in motion. ???
At the bottom of this post is a list of similar subjects. You might read those and see if anyone else who has had this problem posted anything with what they discovered was causing their problem.

I'm only trying to help.

 

[Phantom_II]

Re: Boat leans to one side

I would say it's almost certainly the hydrofoil.

Mine did that too if I left the trim all the way down at any speed.

Scared the bejeezus out of me first time it did that. I thought the boat was going to flip.

 

[solar7647]

Re: Boat leans to one side

Thanks alot, I will remove the hydroil the next time i take it out. It is a fixed, stingray XII. My steering does seem a little weird, real touchy to the right and when you turn left there is more play in the wheel. Is there a way I can bleed the lines, do they have a bleed screw like brakes. Thanks again.

 

[cbavier]

Re: Boat leans to one side

Take the Hydrofoil off an dtry that before doing anything alse. If that doesn't fix the problem. Start a new post or come back to this one. No I don't think there is a screw to bleed like your thinking. The steering is with cables.

 

[solar7647]

Re: Boat leans to one side

I have a power steering set up. I was thinking that there may be air in the lines that is causing a pressure differance, since air can be compressed more that fluid. Thanks!

 

[cbavier]

Re: Boat leans to one side

I have power steering too but there are still cables. Did the problem just start or did it start after you added the hydrofoil?

 

[Jdeagro]

Re: Boat leans to one side

Solar7647;

First, without question the problem is caused by a torque list which is exagerated by (1) the full down trim (why you are running this way I do not know but would like to hear), (2) the hydrofoil, (3) the four bladed prop. This et up is just begging for a torque list to the left. Why?

1) the trim in the full down possition is causing the prop to lift the stern and make the boat ride too much on it's keel (like a teeter totter), 2) The hydrofoil is also lifting the boat at the stern from the center of the boat (even more at top speed than at slow speed) and this increases more as the speed increases, and 3) the four bladed prop adds 25% more resistance in the water than a three bladed prop. The resistance from the prop rotating clock wise, makes the boat list counter clockwise (it is trying to unwind). This is the main reason most helms are on the starboard side as it help to counter balance the prop torque.

Solution, remove the hydrofoil, trim the motor vertical when at cruising speeds. It is likely that you will not need to change the prop, but it is possible.

Now that the list is gone (when you do these things) the boat will have a more difficult time to plane, require more speed to stay on plane, and porpoise when cruising with the trim in the vertical position. You want the trim (prop) vertical because this is the most fuel efficient and power efficient possition). All of the are the reasons why the pProp was changed and the hydrofoil was added. Neither are the correct answer, they are just the common mistakes.

Now add trim tabs that can be or are automatically adjsutable. Prices range from $99.00 to about $500.00 per set depending on your choice. You will not have a listing problem, and the boat will handle better, run more efficiently, and ride better.

 

[solar7647]

Re: Boat leans to one side

Jdeagro- thanks for the break down, I didnt think of it that way.

Cbavier- Its been a while since i put the hydrofoil on so i dont remeber if and how bad it was. I am removing and going for a ride today so I will post my results thanks for the imput, very helpful.

 

[coastalcruiser]

Re: Boat leans to one side

Also would a bent skag cause this, it looks a little off to the left.

Yes that is your problem for sure.
use your trim tabs to balance the boat side to side, if you have a zink behind the prop make sure its strait and those can be adjusted right or left, but if your skeg is bent why not stand directly behind the boat take a photo, post it on here and lets see how bad it is.

 

[cbavier]

Re: Boat leans to one side

Yes that is your problem for sure.
use your trim tabs to balance the boat side to side, if you have a zink behind the prop make sure its strait and those can be adjusted right or left, but if your skeg is bent why not stand directly behind the boat take a photo, post it on here and lets see how bad it is.

"coastalcruiser" I beg to differ with you but a bent skeg will not cause the boat to list. It will or can effect the steering at slow speed however.

 

[coastalcruiser]

Re: Boat leans to one side

A skeg (or skag) is a sternward extension of the keel of boats and ships which have a rudder mounted on the centre line. The term also applies to the lowest point on an outboard motor or the outdrive of an inboard/outboard. In more recent years, the name has been used for a fin on a surfboard which improves directional stability

its bent thats a fact right?
are we trying to help the poster or what? I think I know about boats, I have been boating my whole life and install sterndrives I dont give bad advice and have been on the water for 40 years

 

[solar7647]

Re: Boat leans to one side

Well i removed the Hydrofoil and the it helped a bit. I pulled the boat back out and looking at the skeg it looked even more bent then with the hydrofoil on (hydrofoil was screwing with seeing it stright on) I would say that it was about an inch off center. It was a real slite bend so I bent it back by gentaly tappinig it with a rubber malet careful not to damge anything else, dropped it in and its as level as can be in the water. Thank you so much for the tips and advise, I hope i may be able to help you guys when you run into trouble! Thanks Again. Sorry no pic of skeg i got it strieght before i saw the request.

 

[QC]

Re: Boat leans to one side

It does not help the poster to proclaim "that is the problem for sure". Whether or not you have all of the experience in the world, we never know "for sure" until the problem has been solved. All of these factors may be contributing. I doubt he has trim tabs or he would've mentioned them. Let's also keep our heads please . . .

It does in fact sound like the skeg and the foil were helping each other list to port, but I repeat, "for sure" is impossible to know and should be avoided.

 

[bassman284]

Re: Boat leans to one side

Just a thought - Is there anything like a sonar transducer or speedometer remote close enough to center in front of the prop to be causing the prop to ventilate slightly? A long time ago I saw this happen with a Lund that would lean way over left at speed. Turned out his transducer was directly in front of one side or the other of the prop (don't rmember which). Something to check.

 

[coastalcruiser]

Re: Boat leans to one side

as far as tabs go, maybe think about getting them because they really help keep the boat level at all speeds as well as keeping the bow down in heavy seas. they prevent porpoising and once you have tabs set up right you will know why everyone loves them.
He said he doesn't have a zink skeg and that is wrong because unless its a duo prop, they are necessary for single prop drives and adjustable.
I hope that helps.

 

[QC]

Re: Boat leans to one side

He said he doesn't have a zink skeg and that is wrong because unless its a duo prop, they are necessary for single prop drives

Mercruiser does not use steering tabs on any drives with Power steering anymore, Alphas or Bravos . . .