Trim tabs or engine trim?

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Danfarry

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Hi everyone. Took my antares 8.8 out for its first run today on a beautiful day in conwy.

After pooling out of the channel I increased speed. The boat started to list to port. I tried to counteract this with the trim tabs but wasn't successful. I had the outboard 'all the way down' and was wondering if trimming it up would help level it out?

I'm new to powerboats and I am learning as I go!
 
Trim tabs in my opinion. If it's listing to port (as my Monterey did) you need to drop the left trim tab until the boat levels. Do it bit by bit say in 3 second presses of the button.

If you don't have them fitted, the trim tab indicators was the best £500 I ever spent on my boat. The previous owner had the same problems with listing as there were a couple of small invoices for sea trials. The answer on the bottom of them was "normal".
 
If it's windy the boat will have a natural lean into the wind.
In that case I've found raising the leg a bit makes a big difference.

If it's not due to the wind, then either the trim tabs are needed, or on some legs there could be a trim tab you may need to adjust or replace as this is also a sacrificial anode.
 
Confused replies.

The tab on single prop outdrives is used to counteract the effect of the prop rotation, not the trim.

Drive trim would not normally affect list. Check your trim tabs are working; one of mine leaked and dumped all the fluid in the sea. once repaired and relaunched, the inlet line at the cylinder began leaking ( looks like engine out t replace it !
 
As has has been said, lean is unlikely to be affected by the trim of of the outboard; it's a trim tab issue.

It wouldn't be unheard of for the tabs to be wired the opposite way round to the tabs themselves - in fact, it happens all the time!

Next time you're out, if what you think is the right way isn't working, try the opposite side.
 
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It is possible that the motor was trimmed too far in, pushing the nose down, and raising the stern planing surface so as to become unstable..

I had a similar problem years ago with a very powerful single shaft drive that on full power, pushed the nose down and did much the same..

Great in a head sea, but wet..

Next time out put trim tabs to neutral, and play with the engine trim..

Too much tab is not good on some boats, because as they become unstable , if it is the above... It tends to make it worse..
 
David2452 said:
In fact, that is how they should be wired.
Click to expand...

Yup-on my recent Sunseeker if you pushed down forwards the RHS rocker( of a pair next to each other ) the Port tab would go down .
The effect was the boat 1- would start to lean to the R same side as the switch pair AND push the bow down some what .

So with 2 switches one could trim it in X winds and or head sea s -using both -to get more of the Vee down into the waves but at a drop in speed = more comfy ride .
 
With trim tabs, don't confuse yourself with what trim tab goes down when you press a particular switch - and then attempt to quickly calculate the effect in the boat trim (ie Port switch affects Starboard trim tab position, which then raises or lowers the opposite hand of the hull).

Simply put - Press the Port Button to push the Port side/ nose down. Press the Starbiard button to lower the Starboard side/nose.

It is the case on all boats, that they end up leaning into a crosswind. This happens due to you having to steer into the wind, effectively putting your boat into a slow turn into the wind, which is counteracted by the wind pushing the boat/nose downwind - and thus having a straight heading.

On high sided motorboats it can be quite a lean.

So, if you have a wind on the Starboard side, to counteract the boat being pushed to port, you need to steer to Starboard to keep a straight heading. As a consequence, the boat will lean to Starboard. To level out the lean, press the Port trim tab to lower the Port side/nose.

Trimming the leg up or down might have some minor effect on the lean, but only trim tabs, or redistributing the load on the boat, will fix it (such as getting everyone to move to one side of the cabin or other.)
 
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Although the workings of trim tabs is a fascinating subject..

The original tread post asked the simple question..

With the outboard trimmed right down a list to port occurred, which was not correctable by the use of the trim tabs.

Would running on less of a fully trimmed down outboard make a difference..

The answer to that one is in my opinion probably Yes..

The cavitation plate on the leg is a very powerful tool, pushing the nose down together with the trust of the prop, plus the rotational force would induce a list to port..

When installing race tuned BMW engines in powerboats, we offset the engines about 3 inches on single legs to loose the problem caused by this leverage.
 
Thanks for all the replies everyone.
Went down to the boat this evening. The tabs I think are wired the wrong way down. When I press bow down on the port control, the starboard tab lowers and vice versa.
I also think I need to raise the engine more after reading online about my boat. This would I hope allow the tabs to be more effective by sticking them in more so to speak, and also not lift the stern as much.
 
Danfarry , heres what yer do
Initially you set off with the outboard in the 'down' postion
Then once on the plane you may find it's best to trim the motor up a tad and see whats what
Then use the trim tabs
However until you are on the Plane and happy leave everything alone until you are 'flying' strait and level
It doesn't matter which way round stuff is wired as long as you know, ref the tabs
I,m only up the road, if you want I can come over and go out with you and explain better ref outboard trim de blah de blah, cos that's what I do
Cost yer though
20 Bensons maybe and a bottle of Grog
Cheers
K
:encouragement:;)
 
Thanks for the offer, will probably take you up on it! You can show me through the straits too!
Conwy wasn't as tricky as I expected, just follow the buoys, keep an eye on the plotter/chart/cruising guide.
 
Danfarry said:
Thanks for all the replies everyone.
Went down to the boat this evening. The tabs I think are wired the wrong way down. When I press bow down on the port control, the starboard tab lowers and vice versa.
I also think I need to raise the engine more after reading online about my boat. This would I hope allow the tabs to be more effective by sticking them in more so to speak, and also not lift the stern as much.
Click to expand...

That is wired the correct way - Port button lowers the starboard tab, lowering the port side/nose.
 
Yep they are wired correctly as kennyh says.

I dont have specific knowledge of your hull, but in general it is possible for the engine trim position to affect the lean of the boat. For instance the Fletcher sports cruiser has a significant lean at all throttle levels untill you trim it up, then the hull sits perfectly level.
 
kennyh said:
That is wired the correct way - Port button lowers the starboard tab, lowering the port side/nose.
Click to expand...
Well, if you find that more intuitive, good for you.
But saying that this is the correct way, impliying the most obvious way is wrong, is a bit of a stretch.
It doesn't take a Ph.D. at the MIT to guess what happens by lowering/raising one tab, and operate the switches accordingly...
And FWIW, I can think of several boats where I've seen the tabs controls wired in what you might consider the wrong way:
Sunseeker, Donzi, Fairline, Cigarette, Cranchi, Fountain, Azimut, Ferretti, Hampton, Riva, Pershing - just to name a few of the most well known....
 
David2452 said:
In fact, that is how they should be wired.
Click to expand...

Fair enough, badly worded. By that I meant that it seems natural that you should push the port switch down for the port tab to deploy but it may be wired that the port switch lowers the starboard tab to lean the boat to port.
 
MapisM said:
Well, if you find that more intuitive, good for you.
But saying that this is the correct way, impliying the most obvious way is wrong, is a bit of a stretch.
It doesn't take a Ph.D. at the MIT to guess what happens by lowering/raising one tab, and operate the switches accordingly...
And FWIW, I can think of several boats where I've seen the tabs controls wired in what you might consider the wrong way:
Sunseeker, Donzi, Fairline, Cigarette, Cranchi, Fountain, Azimut, Ferretti, Hampton, Riva, Pershing - just to name a few of the most well known....
Click to expand...

Mine was wired up the "wrong" way round according to this. Press the port button on my boat and the port trim tab lowered. Which seems right in my head anyway - not sure my brain could cope with the other way round
 
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