constant boat drift from side to side

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: constant boat drift from side to side

have you tried replacing the flat anodic plate with the older style fin one? it sometimes helps if you do. try it hard left,hard right and centered. make sure you have prop clearence though/
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: constant boat drift from side to side

You don't have to give up outdrive boats. Just get rid of that Mercruiser and OMC and Volvo single prop drives and move up the the Volvo Duo Prop drives..... Notice I didn't say anything about the Bravo 3's..... anyway. The problem is almost completely eliminated, only minor corrections needed to run a straight course at 600 to 650 rpm. Much better getting on step and a lot more effecient than the single props (Even the Volvo single props).<br />But if you have the, uhhh how does rodbolt put it, oh yea, Black Anchors, then you are stuck with low speed operation that will have the CG checking you for drunk driving.
 

Richard Petersen

Senior Chief Petty Officer
Joined
Dec 17, 2004
Messages
778
Re: constant boat drift from side to side

To all of you that I have offended by my constant , pesky, nitty gritty, redundant details about my problems or friends boat problems. -----------------Before I retired I made a living by modernizing old production machines of all types. The only way I could improve them was to find out all the good and bad features of them. Then go back to the same people at all levels and ask what they think would improve the machine. Funny thing, they all had the complete knowledge between themselves but were never given the oppertunity to express that knowledge or try the obvious best parts in the machine. ------------I will get under the skin of some of you, but you are really helping many people you will never meet. And you are helping the many viewers who watch and never ask directly here. A few " hijack " on to a post. We are not all "tough as nails" like Quietcat or me. The toughest part of these postings is to keep answering the same problems over and over. To those of us who keep doing that, thanks very much for making the mental sacrifices. IT is very appreciated.---------------------Cyclops2
 

Richard Petersen

Senior Chief Petty Officer
Joined
Dec 17, 2004
Messages
778
Re: constant boat drift from side to side

Rodbolt . It is funny that you mention using the plate with the adjustable trim tab. The first lady at Mercruiser suggested that then realized I did not have one on mine. I WIll definately by and try it. If I lose 5 per hour top end great , if I go almost straight. I assume there is only one size tab? I would go right to the largest one if more than 1 is availabe. Does anyone know the part # 's of what I need to do the job the right way the first time. I am getting juiced up about keep her!! Thanks for the hope. My mind is acting up. Stop.
 

Richard Petersen

Senior Chief Petty Officer
Joined
Dec 17, 2004
Messages
778
Re: constant boat drift from side to side

Don S. We first rode a Sea Ray with duo and I did not dock it because the marina had too many turns and I did not want to bang something going in. Asked people and some then said it was no big deal at the time. Rush to buy a boat bit me. Haste makes waste. Thanks for the up date.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: constant boat drift from side to side

cyclops2,<br /><br />I am sorry if I came off harsh. I have read a lot about low speed wander and even the Volvo duo-props applications wander. IMHO it is not an I/O design thing as much as you felt, I have read complaints from many brand and I/O combos. I have been on the manufacturer side (truck engines) for 28 years and it gets under my skin when owners think they understand these products better than the engineers that designed them, so you kinda touched a nerve. Again, sorry.<br /><br />The sizing thing is best investigated on Bennett's web site.<br /><br /> http://www.bennetttrimtabs.com/ <br /><br />There are a couple of other manufacturers too, but these guys are very good and well known. There are also "passive" trim tabs (Smart Tabs) that appear to work well, but I personally LOVE the ability to adjust the tabs while underway for a list from side to side etc. The Smart Tabs will help the low speed wander, time to plane, and stability at higher speeds. Both styles (adjustable and "passive") may even increase top speed if it allows you to trim out the drive any higher at WOT (tabs eliminate the porpoising). If you like fine tuning, go adjustable, if you simply want to go and not think about it, go Smart Tabs (they're cheaper and easier to install too).<br /><br />I am not completely familiar with your transom although I have been playing with a couple of larger Chaparrals lately. I believe the pic below is yours and it will require some careful planning for getting the right tabs. Good luck!!!<br /><br />
Gil%20transom%20resize.JPG
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: constant boat drift from side to side

You're going to get some wander in every boat. Even the 41' Islander Freeport sail boat with a full keel would wander a little bit.<br />These things aren't stuck to a road with rubber tires. Wind, current, waves, anything will effect the steering.<br />The DuoProps do eliminate a LOT of it, as compared to a single prop outdrive. Just because of the counter rotating props not having the prop walk of a single prop.
 

pocoloco

Cadet
Joined
Aug 20, 2005
Messages
23
Re: constant boat drift from side to side

thanks all for you valuable posts!!!<br /><br />i will change the prop and see if there's any difference.<br /><br />cheers!
 

I/O WALDO

Petty Officer 1st Class
Joined
Nov 16, 2005
Messages
320
Re: constant boat drift from side to side

Alpha1 drives have a pair of 9/16 head bolts at the top of the outdrive facing aft which chinch closed a clevis type fitting in the top of the gimbal ring holding the steering pin tightly in place.Hold the wheel steady & try to move the outdrive left & right and see how much play U have.Should be only a few degrees.The bolts should be torqued to bout 40lbs.If allowed to wallow like this too long,it will ruin the gimgal ring(bout$1000+to fix!)
 

Scaaty

Vice Admiral
Joined
May 31, 2004
Messages
5,180
Re: constant boat drift from side to side

Originally posted by pocoloco:<br />at slow speed up to speed on plane the boat drifts left, then right, then left, then right and it does this in a fairly extreme way, making manouverability difficult. When on plane the boat keeps steady.
Maybe this boat left the factory with a "hook" or a "bow" in the hull, or misplaced stringers, and it will never track straight
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: constant boat drift from side to side

every deep v hull i've ever had since the early 60's has had this problem. Deep V Drift.
 

pocoloco

Cadet
Joined
Aug 20, 2005
Messages
23
Re: constant boat drift from side to side

i know what the problem is: steering swivel has slop... Questions on that, I ll post anew...
 

hvac6470

Cadet
Joined
May 25, 2005
Messages
25
Re: constant boat drift from side to side

New to this to but could it be the little trim tab behind prop<br />Not set to a little right or left and a little overcorrecting?<br /><br /> web page
 

sumcat1

Petty Officer 2nd Class
Joined
Jun 27, 2005
Messages
106
Re: constant boat drift from side to side

I had the same problem on a 19' bowrider. Smart Tabs took care of the problem. Also reduced bow rise,on plane speed and porpoising. Best money I ever spent on a boat.
 

I/O WALDO

Petty Officer 1st Class
Joined
Nov 16, 2005
Messages
320
Re: constant boat drift from side to side

what is a steering swivel!!??
 
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