Help

[Mikey B]

I

[Paul D]

Mike,

 

They do work well. I have a pair fitted to Neo and they certainly help to eliminate / reduce any porpoising.

The size you need for a 520 are the ST980-40 tabs ( the man from Nauticus told me ).

 

Also they should be fitted in the position as shown ( also sent by the man from Nauticus ).

 

Just be careful when launching in shallow water as you will probably have read I managed to bend my tab in a 90degree right angle and also managed to break the actuator on the other tab ( superglued this back together and has held for past 2 years ).

 

 

 

[TomBettle]

The flip side is that whilst you gain in particular sea conditions you will lose out considerably in others.

 

To get the best of all worlds you need adjustable (hydraulic or electronic) trim tabs.

 

Tom

 

PS: If a boat is porpoisiong it is usually over trimmed on the engine or badly balanced in the first place.

[Mikey B]

Tom, my Orkney seams to ride bow high most of the time at anthing above displacement speed.

 

I appreciate the hull is semi displacement but I feel its a little light in the bow, would adding some ballast help?

 

All the weight is at the stern with the weight of a 4 stroke outboard, the fuel tank and a pair of 85amp batteries in the lockers just forward of the outboard well.

 

Mikey B

 

 

[djredrupp]

make sure that your engine is fully down (though usually the problem is getting the nose up at planing speeds), and what about keeping an anchor/ chain up front! that would help!

 

Dan

[Paul D]

All the weight is at the stern with the weight of a 4 stroke outboard, the fuel tank and a pair of 85amp batteries in the lockers just forward of the outboard well.

 

That was exactly the issue I had with mine. One you start adding the extra battery and also, in my case, the spare 10litres of fuel plus a livebait tank with say 50 litres of fuel, this starts making the boat stern heavy.

 

As Tom says due to the above the setup was out of balance, I could then induce porpoising over anything like 15/16 knots unless I trimmed the engine in fully ( and at that position the whole setup is not running as efficiently plus with the large prop on the e-tec you get oodles of torque steer and the boat tries to tilt badly and eject the crew - Mark B will testify ! - when the engine is fully trimmed in ).

 

I decided to try some Smart Tabs out and they worked a treat. However, Orkney's are designed to run with the bow fairly high, so not much you can do about that I suspect.

 

This is Neo at speed without trim tabs ( first with the E-Tec and second picture with the Honda 4 stroke ) :-

 

 

 

I will have to get someone to take a picture with trim tabs fitted.

 

[Mikey B]

Thanks Paul, Good pictures.

 

I'll give the smart tabs a try with a set of 40lb actuators.

 

I will let you know how I get on.

 

Will try and get a few photos of before and after fitting the trim tabs.

 

Mikey B

 

[Coddy]

Hi Mikey

 

If you do go ahead with the trim tabs, can I ask a favour and provide me with a report on how you fitted them with any pictures, before, during and after so I can add it to my web site. Fishing Boats & Equipment.

 

Thanks for any help you can provide.

 

Coddy

[Mikey B]

Coddy,

 

I will do my best but I may need help from Paul with photos etc

 

Mikey B