Boat leans when on plane

Navigator_Victory

Petty Officer 1st Class
Joined
Apr 3, 2011
Messages
284
Get up on plane and she leans to the right I trim her out some and get her level and all is good until I turn then it will either lean left or right depending on which way the wind is blowing.....is that normal?

almost every time when I get off plane the boat leans to the right.......there is a fresh water tank on that side and I am thinking I may need to leave it mostly empty?

I also get alot of effect from passengers moving from one side to the other.....again the boat will lean

first cabin cruiser to own and actually to ride on.....so I am not sure if these are norms or not.....I would think the boat would be a bit more stable?
 

rrhodes

Chief Petty Officer
Joined
Jun 24, 2008
Messages
636
Re: Boat leans when on plane

I will assume you have trim tabs, If so could they need to be rebuilt? If you have to keep adjusting your trim I would say the cylinders are leaking?? I am not expert but that is what it sounds like to me.
 

TyeeMan

Master Chief Petty Officer
Joined
Feb 27, 2006
Messages
849
Re: Boat leans when on plane

I have the same problem and I only have a 18 1/2 foot boat. Always wondered if that was normal or if there was a way to remedy that aside from adding trim tabs.
 

dsiekman

Senior Chief Petty Officer
Joined
Jul 7, 2010
Messages
798
Re: Boat leans when on plane

If you don't have tabs, it sounds like you could use them. If you do have tabs, it sounds like either: they're not working, you're not using them, they're not sized right, etc.

I had a similar issue with my boat last year which turned out to be bad trim cylinders on the stbd engine and a bad connection at the trim tab switch. At the end of the day, it probably has a lot to do with the hull shape of your boat. A 25' cruiser is going to tend to be tall for it's length and depth which equates to "top heavy".
 

Joshua Nichols

Lieutenant
Joined
Jun 29, 2009
Messages
1,431
Re: Boat leans when on plane

you may have more weight on the starboard side.. Are ya a big fella?? Take that, some other riders, a battery and the water tank you mentioned.. Starts sounding kinda heavy on the starboard side. HUH? Stick some folks on the other side and see if it makes a difference..
 

TyeeMan

Master Chief Petty Officer
Joined
Feb 27, 2006
Messages
849
Re: Boat leans when on plane

Ok I'm bigger than some, smaller than others, I run about 250. The deal is, no wind she runs pretty true, get a wind from the port side, on plain but barely cruising, and she's running with a stupid looking lean. Full tilt and she's runs straight and true.
My other boat had a Mercruiser drive and it kind of exibited these problems, my new (to me ) boat has a Volvo duo prop and the problem seems to be a bit "worse". Then again totally different boat, different drive, , who knows.

Sorry, didn't mean to hijack this thread, just thought it would contribute to the original posters problems.
 

the vision

Petty Officer 2nd Class
Joined
Apr 9, 2011
Messages
164
Re: Boat leans when on plane

Try moving some weight around to see if it helps. It doesn't take much my 7 year old abought 45lbs. has to stay in the center seat when it's just her the wife and myself. If she moves to one side the boat leans.
 

Ike-110722

Chief Petty Officer
Joined
Sep 3, 2007
Messages
408
Re: Boat leans when on plane

You are talking about a condition called dynamic instability. It all has to do with weight, trim and how much top hammer (superstructure) you have. The most famous case of this was a 1975 Bayliner Cruiser (I forget the length, 25 26, not sure) that would literally lay over on it's side at speed, and the USCG had a surfboat that would do this too if they ran it too fast.

Trim tabs help. Make sure they are big enough and working properly. keeping the weight low and aft helps. Part of the problem is simply the design is too tall. This produces a lot of sail area which makes the boat lean in a cross wind. The other problem is the amount of deadrise. Deep vee boats have more of a tendency to do this at speed than modified vees. It's about how much wetted surface you have when on a plane. The faster you go, the less wetted surface, and the narrow the surface supporting the boat. As the boat moves up, the center of buoyancy moves down away from the Center of gravity. This reduces stability. See http://newboatbuilders.com/docs/stability.pdf

Suggestions, Move all weight as low as possible. Fill that water tank. Don't use the flying bridge in a crosswind. If it starts to do this, slow down a little. That will allow the boat to settle a little and steady up. Get those trim tabs checked out. Oh yeah, make sure it is propped correctly. Props create torque. The wrong prop can create enough torque to create a force tending to make the boat lean.

Although this is unsettling the boat will probably not capsize because of this condition. (although in Bayliner's case it did) just learn to slow down a bit adn take it easier especially in cross winds. This also saves gas.
 

Art Bernard

Banned
Joined
May 4, 2011
Messages
333
Re: Boat leans when on plane

Sounds like you need to work on weight distribution around your boat. Trim tabs will help but do not buy the pre-set tabs, soon as someone moves, you're out of balance again. A good sized "whale's Tail" may also offer some relief.

Art
 

25thmustang

Lieutenant Commander
Joined
Mar 20, 2008
Messages
1,849
Re: Boat leans when on plane

I see this happening to a lot of the 8-8.5' wide express cruisers. They are tall and narrow and the weight can really throw them off balance. I think larger tabs would be the way to go.
 

Navigator_Victory

Petty Officer 1st Class
Joined
Apr 3, 2011
Messages
284
Re: Boat leans when on plane

Thanks for all the thoughts

I do have trim tabs that are not currently working they are both up and in the same position and I have checked before and after running and they are in the same up position. I assume they are frozen or as was said need new cylinders.

Guess I will add them to the list of fixes when I get it out of the water. I can hear the motor run but, the tabs do not move I just assumed it was from sitting so long they might need to be loosened?
 

Tabman

iboats.com Partner
Joined
Feb 21, 2002
Messages
566
Re: Boat leans when on plane

Thanks for all the thoughts

I do have trim tabs that are not currently working they are both up and in the same position and I have checked before and after running and they are in the same up position. I assume they are frozen or as was said need new cylinders.

Guess I will add them to the list of fixes when I get it out of the water. I can hear the motor run but, the tabs do not move I just assumed it was from sitting so long they might need to be loosened?

NV,

Your Trim Tabs are most likley Bennetts. It is pretty rare that an actuator (cylinder) needs to be replaced and most of the time troubleshooting can be done in the water.

I will be delighted to help you get them working. Below you will find the troubleshooting for the system.

Here is a link to a video that covers the basic system and general troubleshooting Link

Here is a link to a video that covers troubleshooting the pump Link

Take a look at step 3 below, it will walk you through the test I think will isolate your problem. Also make sure that both ends of the black ground wire at the pump are clean and tight as low voltage could also cause this problem.

Let me know what you find and I will be delighted to help you get the system running.

Tom McGow
Bennett Marine

Fluid: Automatic Transmission Fluid (ATF) any type. Hydraulic Power Unit is self bleeding, running the Trim Tabs up and down 3-4 times will purge air from the system.

Fuse: 12 volt system use 20 amp in-line fuse on positive. (24v & 32v use proportionately smaller)

Red= Port Valve
Green= Starboard Valve
Blue=Motor Forward (pump pressure)
Yellow= Motor Reverse (pump retract)
Black on HPU=Ground
Orange on Helm=Control Positive

Troubleshooting

1.If one side is not operating reverse hydraulic lines on the front of the Hydraulic Power Unit to determine if the malfunction is in HPU or actuator / hydraulic lines. If after reversing the lines symptom shifts to the other side the malfunction may exist in HPU. If the symptom remains on the same side, malfunction may exist with the actuator / hydraulic lines

2. Is the unit receiving a solid 12 volts? Low voltage will some times cause the solenoids to not open preventing the tabs from moving even though the pump motor is running.

3. Conduct the following test:
Remove the wires from the helm control and touch together as follows:
Operation=Reaction
Orange (+), blue, red= Port trim tab down
Orange (+), blue, green=Starboard trim tab down
Orange (+), blue, red, green= Both trim tabs down
Orange (+), yellow, red= Port trim tab up
Orange (+), yellow, green=Starboard trim tab up
Orange (+), yellow, red, green= Both trim tabs up

If the trim tabs function correctly for each wire grouping then the switch is at fault. Also note that any loose or missing screws on the back of the switch (whether a wire is connected there or not) can cause the pump to malfunction.

This test may also be done right at the pump by substituting a "hot lead" for orange. There is usually a connector to the wire harness within a foot or so of the pump. You want to check this connection for corrosion. You may wish to cut the connector off on the pump side and try the test on bare wires.

4. If you suspect corrosion on the wire connector near the pump, cut it out, test as above and reconnect using butt splices.

5. If you conclude the problem is in the pump, contact me. Bennett Trim Tab Systems carry a five year warranty.

6. Check to see if there is a relay in line on the wiring harness near the hydraulic power unit. If there is it is an Interrupter Relay (IR1000). It prevents the system fuse from blowing if you try to actuate one trim tab up and the other down at the same time. After you test as outlined above, try removing the relay from the wiring harness and retest the unit.(Note: the interrupter relay is no longer used in current Bennett Trim Tab systems and has been replaced with a Switches that "lock out" preventing a blown fuse).
 

emoney

Commander
Joined
Jul 19, 2010
Messages
2,551
Re: Boat leans when on plane

Sounds like you got it answered. Lot's of wind resistance coming from the cabin I'd assume. Hey, if you put a sail on it, you'll be glad when it "leans"!!!
 

partskenn

Petty Officer 1st Class
Joined
Jan 23, 2011
Messages
249
Re: Boat leans when on plane

Operable trim tabs would certainly help, but I think a few people were correct when they blamed it on the boat itself. I have a Sea Ray 268, 26.5 ft, 8.5 beam. It can act much the same way, especially if there is much of a wind. People moving around, full or empty water tank also affects my trim. I usually cruise with the bimini up, and when I turn, the wind uses it a sail, and I have to readjust the trim tabs almost every time. Oh well.
 

Navigator_Victory

Petty Officer 1st Class
Joined
Apr 3, 2011
Messages
284
Re: Boat leans when on plane

WOW what a troubleshooting guide THANK YOU!!!!

Glad to hear I am not the only person experiencing this issue.....
 

dockwrecker

Lieutenant
Joined
Mar 10, 2006
Messages
1,392
Re: Boat leans when on plane

Tabman to the rescue AGAIN!!! (ya gotta love Bennett...)
This is totally a tab issue and your familiarity with utilizing them while under power. No you're not alone. Express cruisers over 23' are a nightmare without good adjustable tabs. Your problem will be solved as soon as you fix them and learn to use them. Good Luck!
 

Mi duckdown

Commander
Joined
Apr 14, 2007
Messages
2,575
Re: Boat leans when on plane

With proper/ working bennet trim tabs, you can actually steer the boat with the tabs.
 

Mac525

Petty Officer 3rd Class
Joined
May 8, 2011
Messages
76
Re: Boat leans when on plane

This can also be caused by a stern lifting prop lifting the stern to high and or a drive mounted to low IE the anti cav plate below the bottom of the keel. ouboards are a fairly easy fix for the latter but if your a stern drive your kind of stuck with it try a prop with no lifting properties
 

smokeonthewater

Fleet Admiral
Joined
Dec 3, 2009
Messages
9,838
Re: Boat leans when on plane

I'll share another possible cause... My 26' Carver (8' beam flybridge cruiser) had this problem BAD with a whale tail on the outdrive (came with the drive so I tried it) but once I took it off the problem was nearly gone... The boat still had a tendency to lean in a crosswind and was sensitive to weight distribution but not nearly so bad.
 
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