Trim tab not suffice to counter-act prop torque - steering too loose?

muncedog

Seaman
Joined
Nov 13, 2014
Messages
67
So I have fully adjusted my trim tab above the prop as far as it will go and while it helps the pull to port (Edit - I meant starboard sorry!), it hasn't removed it - you certainly wouldn't want to let go of the wheel at speed!

Two questions -
Iis there a steering stiffness adjustment to deal with this such that if you let go of the wheel it wouldn't violently swing to port?

Could this effect be due to hull shape/prop selection or motor height - I have recently checked height it looks like the plate is around 1inch above water when planing - seems about right!

Thanks in advance!
 
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64osby

Admiral
Joined
Jul 28, 2009
Messages
6,799
What type of mechanism do you have?

I'm not aware of any tension adjustment on steering systems, unless you count corrosion. :watermelon:

An NFB (no feed back) system may be the cure. After installing one the prop steer is no longer an issue.
 

Slip Away

Lieutenant
Joined
May 11, 2010
Messages
1,431
Put a 4 blade prop on the boat to minimize the pull. Tabs should not really help the prop steer, no matter how you adjust it/them
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,030
Your boat pulls to port? Do you have a left handed prop? If she pulls hard, NFB steering will hold the steering straight, but turning the wheel will still require you to overcome the steering torque, when turning to starboard. I presume you have a high-speed/performance boat?

A torque-tab should help. You might do a search for them and see if it works. I fabricated one out of a "discus-shaped" zinc anode, for my speedboat. It works very well, but took some trial and error to get the right size and thickness.
 

Natesms

Chief Petty Officer
Joined
Sep 8, 2012
Messages
464
On my old boat I had bad pull when it was trimmed all the way down. Trimming up reduced the pull significantly. Might try adjusting the trim to see if that helps.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
I've seen folks screw a small thin metal plate to the trailing edge of their skeg and bent in the right direction to help overcome torque steering....it's very similar to the ones on the vertical stabilizers of aircraft for trim purposes....Some Yamaha outboards actually have curved skegs to help with torque steering.....The perfect solution(but expensive) would be to add hydraulic steering which would eliminate the torque steering.....
 

Watermann

Starmada Splash of the Year 2014
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Jan 12, 2013
Messages
13,747
Motor info and boat would help but most steering torque is overcome trimming the motor out after getting on a plane. If you don't have a TnT unit then you can try moving the thrust bar up a notch.
 

mr 88

Commander
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Nov 3, 2010
Messages
2,115
I have a mercruiser outdrive without PS and it pulls hard to the port side as well.
 

JimS123

Fleet Admiral
Joined
Jul 27, 2007
Messages
7,952
You adjusted the tab the wrong way.
The tab is broken off.
The tab is the wrong one for the motor.
The lower unit is damaged.

All possibilites, but likely your motor is set too high.

You have provided little data! OB or I/O? HP, etc...
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Let's see a picture of your tab.

If your boat wants to go to port, you need the front edge of the tab pointing to starboard.

pulling to port seems odd, should pull to starboard
Agreed. Most engines with right hand props are going to want to go to starboard naturally.
 

muncedog

Seaman
Joined
Nov 13, 2014
Messages
67
Hi all,
Many thanks for many answers- firstly, my apologies, I am a muppet -it is starboard it pulls to, not port - I have edited my original post to reflect this!

To answer the questions in turn:

-The mechanism is mechanical rack and pinion cable steering.
-What I have called 'trim tab' others have called torque tab, the small adjustable fin above the propeller that came with the outboard. Its rear end is toward the starboard side of the boat, the opposite of what a rudder would point to get the same effect (the counter-intuitive but correct way). It is fully adjusted this way.
-4 blade prop sounds interesting, I am thinking of getting another prop at some point for good hole shot (starting wake boarding)
-The outboard is a 130HP Johnson 1999 on a 17ft cuddy cabin boat (buccaneer 510 1990 hull)
-Interesting comments on trimming up, I will try this out.

To be honest Its my first boat I have only been out on a handful of times. At sea (say 1-2ft chop) is it reasonable to expect to plane at what speed,given it cuts in and out of the chop - can you trim effectively on this chop? They always show ideal flat lake water on video tutorials and there is me bouncing on chop at 25 knots!

As for steering starboard, its not 'super-hard', your not fighting the wheel, just I certainly wouldn't want to let go even for a second at any sort of speed, perhaps this is normal!?

Thanks again!
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,030
Torque tabs are a different thing than the aluminum fin that most Johnnyrude's have. A torque tab is a wedge of metal that is bolted or riveted to the skeg, usually on the starboard side.

With your setup, I would not expect you to need one, and that the fin you have should be able to correct the issue.
 

muncedog

Seaman
Joined
Nov 13, 2014
Messages
67
Ahh that makes sense - so what is the correct name for the fin I have, is there one!?

Anyway, for some reason mine fully tilted doesn't seem enough to fully cancel the steering torque - I will try adjusting the (actual) trim and see what affect that has.

It doesn't hugely concern me - its a used boat and motor - perhaps the set-up has changed over time (propeller etc).

Just better not let go of the steering wheel at any point!
 

smokeonthewater

Fleet Admiral
Joined
Dec 3, 2009
Messages
9,838
you were right from the start it IS a trim tab... there are ALSO trim tabs that mount on the hull and serve a totally different purpose... the people who mentioned them either didn't pay attention to your question or didn't know obout the steering trim tab.

You might also look into a bigger tab... they come in multiple sizes for many motors and drives....

As mentioned if your motor is trimmed all the way down that may cause this problem...

Understand that the trim tab adjustment it a trade off... it will be adjusted for a certain speed and will under or over compensate at other speeds...

Look into a NFB helm for your boat..... best thing since sliced bread... You can literally let go of the wheel at any time and any speed and it won't budge a bit.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,019
The other question that has not been asked........ Do you happen to have a "Doal fin" or similar fin on the motor? Does your cuddy have any trim tabs mounted to the boat?

The rack and pinion steering is not a NFB (No feed back) system.

None of the adjusting or testing can be done in choppy water ;)
 

smokeonthewater

Fleet Admiral
Joined
Dec 3, 2009
Messages
9,838
Bob, if you are saying that a NFB helm isn't available in the rack style, actually they are..... If you were just saying he doesn't currently have one then nevermind ;)
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
Not saying you don't know what you are doing but did you make sure you turned the tab in the correct direction? My last boat didn't have power steering and I was able to correct the pull with just a small adjustment of the tab.
 

dan02gt

Chief Petty Officer
Joined
Aug 30, 2012
Messages
463
Hi all,
Many thanks for many answers- firstly, my apologies, I am a muppet -it is starboard it pulls to, not port - I have edited my original post to reflect this!

To answer the questions in turn:

-The mechanism is mechanical rack and pinion cable steering.
-What I have called 'trim tab' others have called torque tab, the small adjustable fin above the propeller that came with the outboard. Its rear end is toward the starboard side of the boat, the opposite of what a rudder would point to get the same effect (the counter-intuitive but correct way). It is fully adjusted this way.
-4 blade prop sounds interesting, I am thinking of getting another prop at some point for good hole shot (starting wake boarding)
-The outboard is a 130HP Johnson 1999 on a 17ft cuddy cabin boat (buccaneer 510 1990 hull)
-Interesting comments on trimming up, I will try this out.

To be honest Its my first boat I have only been out on a handful of times. At sea (say 1-2ft chop) is it reasonable to expect to plane at what speed,given it cuts in and out of the chop - can you trim effectively on this chop? They always show ideal flat lake water on video tutorials and there is me bouncing on chop at 25 knots!

As for steering starboard, its not 'super-hard', your not fighting the wheel, just I certainly wouldn't want to let go even for a second at any sort of speed, perhaps this is normal!?

Thanks again!

If you're not trimming up that's your problem. Your boat is bow steering. Bump the trim up a little once you get on plane and you're going to have a whole new boat. Honestly, it may be a good idea to have a friend that is a experienced boater take you out and show you a few of the "tricks" .
 
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