Boat motor peeps?

[Spurhunter]

I've always called those "trim tabs". I knew they were anodes also. I pulled my manual just to verify, because I though it talked about adjusting it to help with veering/steering issues.

Absolutely. They have a huge impact on steering. I'm surprised someone with any boat experience at all would argue that.

 

[Pilchard]

Incorrect. If my trim tab is out of the water my motor is over trimmed. And everything impacts speed. Some guys lightly sand the running pad of their hull so it doesn't "stick" to the water.

We can agree to disagree. Here is a 100mph flats boat:

 

[Pilchard]

Absolutely. They have a huge impact on steering. I'm surprised someone with any boat experience at all would argue that.

Perhaps none of my boats needed adjustment? I've owned some very fast boats.

Where I come from a trim tab is a hydraulic tab on each side of the boat on the transom. The part we are referring to was always referred to a a zinc. Anyways, back to hunting.

 

[7mm08]

These are sacrificial anodes meant to protect metallic parts from corrosion caused by electrolysis. They are most important in saltwater as they catch corrosion that would otherwise cause serious problems.

In fact they are made of different materials depending on salt vs fresh. Zinc vs magnesium perhaps?

I'd argue that if that part of your lower unit is in the water while your on plane, you aren't running your boat for top speed due to it being improperly trimmed/jacked. They definitely do not impact speed.

On big boats you may have dozens of these anodes. On a small outboard, usually just one or two. They have nothing to do with steering or boat control. Only designed in that shape to eliminate drag at low speeds.

Exactomundo!

 

[WTM]

have no clue. id rather pay someone to do it. my luck the lower unit would fall of half way up the river.

 

[Spurhunter]

We can agree to disagree. Here is a 100mph flats boat:

You had to find a 100 MPH flats boat, which, according to the guy's page is as rare as a dodo bird, to prove your point?

 

[hammer33]

That Skeg, tab, zinc or whatever you want to call it plays a vital role in controlling steering torque.

My old bass boat with a 115 was tuned for almost zero torque at max speed with motor trimmed up.
When you trimmed the motor down it would about pull your arm out of socket the torque was so bad. If you let go, the boat would slam the motor full stop to the right and could flip the boat at full throttle.
We adjusted the skeg to reduce the torque at regular trim levels and it was MUCH easier to steer AND was MUCH MUCH safer. It wouldn't hammer over into an uncontrollable spin.

 

[Pilchard]

I'll admit, I learned something here. Never knew the zinc trim tab was used for this purpose. Never had an issue on any of my boats.

Whatever you do, please don't remove them though. They aren't "optional" and serve another very important purpose.

 

[Spurhunter]

I'll admit, I learned something here. Never knew the zinc trim tab was used for this purpose. Never had an issue on any of my boats.

Whatever you do, please don't remove them though. They aren't "optional" and serve another very important purpose.

*in saltwater*

 

[Doecrusher]

Or if you keep your boat in the water for long periods of time.

 

[Pilchard]

*in saltwater*

About Freshwater Anodes - Martyr Anodes

martyranodes.com

 

[TRIGGER]

The "trim" part of the trim tab is not needed with hydrologic steering. It helps with cable or tiller steer to counter act the torque of the motor.

 

[Pilchard]

The "trim" part of the trim tab is not needed with hydrologic steering. It helps with cable or tiller steer to counter act the torque of the motor.

And there you have it.... I never owned a boat without hydraulic steering but I do remember running a few that would want to turn hard over if you let go of the wheel. Perhaps those would have benefited from rotating the zinc.

One of my bigger boats(300 Yami) had a flat zinc with no fin on it now that I think of it.

 

[TRIGGER]

Now that I look at it I'm not sure what "hydrologic" steering is lol