Trim Tabs on Avon Searider 4M

[Mextli]

Hi all

Has anyone ever mounted "proper" adjustable trim tabs on a 4m Searider? Not talking about the automatic ones but the electrical ones.

Id love to be able to push the bow deeper into the waves in head seas, and Im afraid my weight distribution is slightly off to the rear.

[Pikey Dave]

Try putting a 25kg bag of sand in the anchor locker

[jeffstevens763@g]

Don't forget your inducing drag with the tabs, what in terms of weight is making it sit stern down if that's your boat in the picture driving position well forward I guess fuel under the seat so engine trim should sort a level plane. You need the bow to climb the wave or you risk stuffing and losing speed/ momentum or sudden stop if bow heavy. Some boat builders put ceramic balls in resin at the keel in the anchor locker but it has to be worked out properly,personnely I would sooner move kit forward to achieve balance OMO

[Mextli]

I have a 40l fuel tank at the transom, thats my problem, and usually some kit behind the console as well.

Here is a picture



Concerning drag and stuffing issues, shouldnt it be possible to fully retract the tabs?

[breezeblock]

move the tank towards the front ?

[Mextli]

Tank wont fit in front of the console, its too fat :/ been thinking about two 25l tanks but that would neccesitate a lot of pipework (which is quite short now) and the fuel gauge would not fit as well as they would be harder to tie down securely.
My console is very far foreward as I need the deck space.

Power Trim would propably solve all my issues. I can trim the bow down by manually trimming the engine but this makes it very prone to stuffing in following seas. Just for tackling on head seas this would suffice, but you can hardly stop every now and then and retrim your engine manually, as the trim thing is below the waterline and very awkward to reach and adjust.

I have been looking for used power trim units for my Yam but unfortunately they seem quite rare.

Trim tabs wouldnt be as practical, but the seem cheaper (most PTT units i
found are either in the states or above 600 quid or both.)

[willk]

Originally Posted by Mextli

Concerning drag and stuffing issues, shouldnt it be possible to fully retract the tabs?

Tabs are approximately in line with the hull in the "fully retracted" position, so there will still be some (very little) drag. IMO putting fully controllable tabs on a SR4 is overthinking a problem - moving a little weight around will do the same job. With your helm so far forward even the extra pies you ate over Christmas may do the trick!

[Mextli]

Originally Posted by willk

Tabs are approximately in line with the hull in the "fully retracted" position, so there will still be some (very little) drag. IMO putting fully controllable tabs on a SR4 is overthinking a problem - moving a little weight around will do the same job. With your helm so far forward even the extra pies you ate over Christmas may do the trick!

Hopefully.

Overthithinking the problem sounds nice though. [emoji23]

[Pikey Dave]

I hadn't realised that your engine wasn't PTT, therein lies the problem. There's no reason why you couldn't add trim tabs, but this isn't resolving the underlying cause of your problem.

[Mextli]

Finding light 50 HP engines with PTT that arent too costly is unfortunately rather hard [emoji22]

PTT would definitly improve the trim issues.

[beamishken]

Wouldn't it be more cost effective to sell the manual trim engine and buy a power trim engine. Probably not a lot different in money terms than adding trim tabs and should solve you problem
Make the boat a totally different animal

[Mextli]

Originally Posted by beamishken

Wouldn't it be more cost effective to sell the manual trim engine and buy a power trim engine. Probably not a lot different in money terms than adding trim tabs and should solve you problem
Make the boat a totally different animal

Got the engine very cheap and did a lot of restoring work to it, so Id be very reluctant to part with it. Especially that yam or honda 50s with PTT arent exactly cheap.

[Last Tango]

A bit outside the box........but, instead of a bag of sand how about a ballast tank "ski-boat" style and some pumping arrangement to fill and empty it?

[Mextli]

Would be an interesting idea, but after Pikey Daves post I decided to bite the bullet and bought a used PTT unit that should fit my engine from the States. If it works and fits it would be perfect, if not one can still sell it over here.

So for now, no more trim tabs. Will think about them once PTT project is done and i have some more boat money.

Once my trim unit has arrived Ill report back.

[beamishken]

I understand about not wanting to part with the engine you know but how about buying a running power trim engine and swapping the bits over then reselling it as a none power trim engine or even breaking it for spares
Yours looks like a 2 cylinder 50? If it is then at that age even a power trim engine is probably worth not much more than your being qouted for a used power trim unit
The other thing to consider is has the foam in the rear buoyancy module under the deck become saturated and weighing the stern down

[Pikey Dave]

Originally Posted by Last Tango

A bit outside the box........but, instead of a bag of sand how about a ballast tank "ski-boat" style and some pumping arrangement to fill and empty it?

+1 cracking idea[emoji106]. You could integrate it into the flux capacitor circuit & control it via the di-lithium matrix.

[willk]

Originally Posted by Pikey Dave

+1 cracking idea[emoji106]. You could integrate it into the flux capacitor circuit & control it via the di-lithium matrix.

That's just silly.

If it was me, I'd glass a rail into the deck and rig a pulley system to run a block of lead fore and aft. You could use a sailing winch. Not sure where I'd store the handle when not in use. It's a can of worms.

[matt h]

You just covering up the issue, which is 40kgs of fuel/extra weight on the transom/stern, the Hulk tanks fit nicely under that consol, 22L if i remember and if you need to carry an extra fuel capacity then add a Hulk tank 12L or the 22L up front as shown.
Thus leaving your stern light as it should be especially with out PTT.
SR4 's are small slim boats and don't take kindly stacking weight up on its arse!

If you want it to handle better, your going to have to move the fuel or counteract a 40kg problem dude

[Last Tango]

Originally Posted by Pikey Dave

You could integrate it into the flux capacitor circuit & control it via the di-lithium matrix.

That would be almost as much over the top as fitting trim tabs to a 4 mtr boat.
A simple switch or lever like Mastercraft, Ski Nautique, Malibu or the RLNI use would do fine.

[Mextli]

Originally Posted by beamishken

I understand about not wanting to part with the engine you know but how about buying a running power trim engine and swapping the bits over then reselling it as a none power trim engine or even breaking it for spares
Yours looks like a 2 cylinder 50? If it is then at that age even a power trim engine is probably worth not much more than your being qouted for a used power trim unit
The other thing to consider is has the foam in the rear buoyancy module under the deck become saturated and weighing the stern down

Yep, it's the 2 cyl 55 HP engine.

afaik any PTT from a Yamaha up to 90 HP from the 90's would fit, those are the three cylinder 2-Stroke Autolube engines and they don't go cheap, they are in fact quite hard to get for a reasonable price(It's the reason I run the 2-Cyl, because it cost a third of the same HP model with 3-cylinders, PTT and Autolube.)

As much as I'd love to move the fuel tank foreward, it would either cost me range(which I really can't go without) or deck space(As the console would have to move back which would involve major work, which is not an option either)