Alignment issues?

[zippy83]

Hi All,

I have a problem with my 95 16' Lowe fisherman serries boat. Sometimes it seams like when I am at full speed (25-30mp/h) that the boat is pulling me to the right, when that starts hapenning and when I ease down on the throttle it keeps pulling me more and more to the right and I feel like almost flipping to the side. I have checked the boat ballance usually when I am alone I shift my gass tank to the opposite side so that everything is ballanced, om the opposite side I have my battery and all of my equipment. I am not sure what is causing the issue?

Thanks
Zipp

 

[thumpar]

Re: Alignment issues?

What do you have for a motor? Does it have a fin anode that you can turn?

 

[tazrig]

Re: Alignment issues?

Zip, if memory serves you have a 50hp merc. if the boat is balanced correctly (level) then what you are experiencing is prop torque. That is normal. To correct it what you need to do is get an anode with a fin on it that looks like the one in this photo just in back of the prop. You want to instal it one or two clicks to the right facing the back of the engine and try it. If that is not enough to counter the torque then move it one more click and re-try keep moving it over a click at a time until the boat goes straight

Let us know how you make out.

 

[zippy83]

Re: Alignment issues?

Zip, if memory serves you have a 50hp merc. if the boat is balanced correctly (level) then what you are experiencing is prop torque. That is normal. To correct it what you need to do is get an anode with a fin on it that looks like the one in this photo just in back of the prop. You want to instal it one or two clicks to the right facing the back of the engine and try it. If that is not enough to counter the torque then move it one more click and re-try keep moving it over a click at a time until the boat goes straight View attachment 223409

Let us know how you make out.

Taz, yes your memory serves you well. its the 50hp merc. Are you refering to the little fin that is upside down?

one of these?

Replacement Trim Tab Anodes For Mercury/Mariner, Force Part Number 31640 - iboats

 

[tazrig]

Re: Alignment issues?

Yes those are the fins. Just call iboats at 1-800-743-1123. give them the make model and year of your engine and let them know whether you are using the motor in salt or fresh water or both and they will tell you which one you need.

 

[Knot Waiting]

Re: Alignment issues?

Taz, yes your memory serves you well. its the 50hp merc. Are you refering to the little fin that is upside down?

one of these?

Replacement Trim Tab Anodes For Mercury/Mariner, Force Part Number 31640 - iboats

Yep, that's the one he's talking about. Called a trim anode and is adjustable with an allen wrench. Loosen it and rotate it slightly left to offset the effect of the propwash. It's normal for a boat to pull slightly because of said prop wash. Also why most helms are located on starboard, to reduce the affect the torque has on raising one side of the boat over the other.

 

[zippy83]

Re: Alignment issues?

Thanks All,

So when I install those I should slightly turn it to the right (the side that pulls)?

 

[Knot Waiting]

Re: Alignment issues?

Thanks All,

So when I install those I should slightly turn it to the right (the side that pulls)?

To the left. We are operating under the theory that the propwash is cause for the pull so you need to offset force of the wash. If you angle it right it will increase your pull (if wash is the cause).

 

[R DAVIS]

Re: Alignment issues?

Thanks All,

So when I install those I should slightly turn it to the right (the side that pulls)?

Turn the TRAILING edge of the tab in the direction the boat tends to pull. In your case to the right.

 

[zippy83]

Re: Alignment issues?

Ok thanks... I just got home and noticed that I allready have the anode installed, however I dont see any way that this anode can be turned to any side.. Any special tricks I need to try?

 

[thumpar]

Re: Alignment issues?

It is screwed on somehow. You need to loosen it and turn then tighten it up.

 

[tazrig]

Re: Alignment issues?

look either under the fin or on top of the engine where the center of the circle part of the fin would come through the motor. You may have to remove a cap to access either an allen screw or bolt. Loosen this bolt until you can pivot the fin. standing in back of the fin facing the back of the motor pivot the fin counter clockwise and then tight the bolt or screw. you will have to adjust it and play with it to get it right but always stand in back and rotate it more counter clockwise each time you need more.

 

[zippy83]

Re: Alignment issues?

Taz,

Yes there is a bolt on the top of the lower unit. I will try turning it between 12 and 1 oclock. Maybe that is too much but I will play with it.

Thanks all

 

[Bob_VT]

Re: Alignment issues?

The limits on a trim tab to adjust it are very small. I usually like to over-adjust in one direction (I max the fin to one side)...... run the boat and start making finer adjustments from there.

If your boat is loaded with many of the fish in your avatar picture....... then you deserve to have it pull you......I am jealous - nice fish!

 

[zippy83]

Re: Alignment issues?

The limits on a trim tab to adjust it are very small. I usually like to over-adjust in one direction (I max the fin to one side)...... run the boat and start making finer adjustments from there.

If your boat is loaded with many of the fish in your avatar picture....... then you deserve to have it pull you......I am jealous - nice fish!

Roger that That sounds like a good idea to do while out on the water.

As for the fish I wish the boat was full of them but unfortinatly it has been a few yers since I got a nice big one

Thanks

 

[Fed]

Re: Alignment issues?

I will try turning it between 12 and 1 oclock.

Wrong way zippy.

 

[zippy83]

Re: Alignment issues?

Wrong way zippy.

Ok then it will be between 12 and 11

 

[tazrig]

Re: Alignment issues?

Zip, stand in back of the motor and rotate it counter clockwise. 12-11-10-9-8-7-6-5 etc

 

[zippy83]

Re: Alignment issues?

Roger that.
Thanks Taz

 

[UncleWillie]

Re: Alignment issues?

Yes there is a bolt on the Top of the lower unit. I will try turning it between 12 and 1 oclock...

Zip, stand in back of the motor and rotate it counter clockwise. 12-11-10-9-8-7-6-5 etc

Wrong way zippy.

Ok then it will be between 12 and 11

Now, even I am confused!

You want to induce a Left turn to counter the Right Turn tendency.
Even this simple explanation can cause confusion.

Let us assume a Tiller Steered OB Boat for simplicity sake.
To Turn Left, you push the Tiller to the right, causing the the aft end of the motor to swing to the Left as viewed from behind.
The Rudder and Prop Thrust push the aft end of the boat to the Right, the Bow swings to the Left and a Left turn ensues.

The direction you turn the Rudder Trim Tab depends on your Frame of Reference.
To induce a Left turn to the boat using the Rudder Trim Tab...

Turn it to the Left, Counterclockwise, looking Down from the Top.
Turn it to the Right, Clockwise, Looking Up from the Bottom.

This will push the aft end of the Drive Unit to the Left as viewed from behind.
The Aft end of the boat goes to the Right and the Bow Turns to the Left as intended.

The trim tab is not an extension of the rudder as common sense might assume. It works backwards.
The trim tab pushes the rudder to one side and the rudder pushes back moving the stern opposite the direction of the tab.
A "Right Rudder" set on the Tab causes the Main Rudder to be forced into a "Left Rudder" Position. And the Bow goes Left.
Confused? Read it again, Slowly!