Where are the trim tabs at full up?

[inohv8]

I recently purchased a 20.5 foot four winns. it has what looks to to be newer trim tabs and a new hydrolic system for it..
I have never had a boat with tabs before but when both tabs are full up, they sit down below the hull by about 20 degrees which does not seem right to me... I went the boat show her in toronto and tryed to ask the people there, but they said its different for every boat, which sounds like BS to me as it's not logical... I assume that the tabs at full up should be at least level with the hull line and down from there...
does anyone have some info on where it should be???
just to let you know, when I am running and look back, I can see 3 rooster tails, one from the outdrive and two smaller ones from the tabs when they are suppose to be up...
Feedback is appreicated...

 

[QC]

Re: Where are the trim tabs at full up?

That is BS!!!! They should be slightly angled "up" compared to the flat plane of your bottom. They are either not working properly, not being properly applied (switch use) or they have been installed wrong (worst situation).

Please let us know what model these are. You said hydraulic, so they are probably Bennett's, but there a few other hydraulic trim tab manufacturers as well. I have a Bennett Manual in pdf format. PM me your emaill addy and I'll send it to you, it has a spec for this, and I think it is actually a measurement of how high the aft edge should be above a straight edge placed on the bottom as opposed to a degree spec . . . The fact is that it really doesn't matter what manufacturer for this, but it would be nice to know.

I mentioned switch use. If wired correctly, they work opposite to what you might initially think. I can;t imagine that you would not "see" the difference, but are you sure that you are looking at full up? 20 degrees is a LOT. How far down can they go from there?

 

[Dhadley]

Re: Where are the trim tabs at full up?

At full up they should be above level with the hull. They should also be mounted so the base is at least a 1/4" above the bottom. Most everyone mounts them flush.

If the tabs won't come up above the hull you can never "lose" them and they will always be trying to push the bow down. Even if they come up past the hull only slightly, they will still always affect the ride attitude. Remember, water comes off the hull at an upwards angle.

In my opinion (for whatever that's worth) the only correct way to mount remote movable (electric or hydraulic) tabs is to have them recessed. Smart Tabs are usually an excellent choice for transom mounted tabs. The pressure cylinders are custom chosen and adjusted for a given installation. But they still have to be mounted correctly.

 

[QC]

Re: Where are the trim tabs at full up?

I like Smart Tabs for some users and applications too. Frankly, my biggest concern is that you can never completely "lose" them as Dhadley put so well . . .

 

[stevens]

Re: Where are the trim tabs at full up?

As several have already mentioned:

Many tabs are wired so that when pressing the upper part of the switch (often labelled "Bow Down") the tabs go down, and vice versa. May seem counter-intuitive at first. Could it be that you've accidentally measured the angle in the full down position instead of the full up position?

Or: You did say Hydraulic tabs, but if by chance they happen to be Smart Tabs, they should rest at an approx. 25 degree angle.

Or: somebody inept simply mounted these wrongly, in which case you'll need to reposition the upper strut mount to the correct position, and properly seal the old holes.

 

[dingbat]

Re: Where are the trim tabs at full up?

 

[Dhadley]

Re: Where are the trim tabs at full up?

Great pic! Prime example of tabs barely mounted high enough assuming the bottom of the tab at the transom is indeed 1/4" above the straightedge. And further assuming the tabs are at full up, not nearly enough "Up" travel.

 

[mattttt25]

Re: Where are the trim tabs at full up?

i wonder if stevens was on to something. tab controls can be a little misleading the first time around. especially realizing the port switch controls the starboard tab. hopefully it was just that- pushing them the wrong way.

 

[Dhadley]

Re: Where are the trim tabs at full up?

Agreed, 20* down in the full up position can't be right (let's hope). While stevens is probably dead on as to the switch direction it's brought up a great overall point about trim tab mounting and how little sales people really know about them, as demonstrated in inohv8's conversation with folks at the show he attended.

 

[HighTrim]

Re: Where are the trim tabs at full up?

Inohv8....went to the TO boat show yesterday as well. Was greatly pleased with the turnout and new products. What I was not impressed with was the fact that the knowledge from the salesmen and dealers was mediocre at best. Many were admitted "yard boys" there to make some money as salesmen for the weekend.

 

[QC]

Re: Where are the trim tabs at full up?

If I had a dollar for every boat show puke that told me "this hull doesn't need trim tabs". Or "you don't need the V8", or "this boat easily does 60" I'd have, well, uh, maybe $75 . . . Anyway, it is amazing to me how little they know. I guess it's the same thing at the Auto show too. You need to find the shop guys or an engineer.

BTW, I want credit for first suggesting switch operation ^^^^ Stevens is a great fellow trim tab proponent, but he simply stole my suggestion

 

[Dhadley]

Re: Where are the trim tabs at full up?

OK, he did indeed pick up on what you were saying. I picked up on the "works opposite" thing but was thinking about the starboard switch runs the port tab deal. You're absolutely correct when comparing a trim tab switch to an engine trim switch. "Bow up" on the switches is opposite. Good point.

I guess I'm used to what each switch does and never think about it. Trim tabs provide negative trim (bow down) and no positive trim (bow up). Trimming the outboard or outdrive provides some negative trim but is mainly designed for positive trim. Tabs do provide the ability to adjust the ride side to side too.

 

[stevens]

Re: Where are the trim tabs at full up?

BTW, I want credit for first suggesting switch operation ^^^^ Stevens is a great fellow trim tab proponent, but he simply stole my suggestion

Nah, no theft here, I merely expanded on your previous suggestion. The credit is all yours!

 

[inohv8]

Re: Where are the trim tabs at full up?

HI folks.
Thank you soooo much for your information... I should give you some highlites that led me to the question..
When I had the boat out of the water, I had my son flip the switches in both directions until the pump grunted.. and for sure the full up was still about 20 degree or so under the hull line... I also asked him to hit both switches simaltaniously and the one closer to the pump, hit dead stop before the other.. Starbrd, went faster.. so I guess the plumbing is all screwed up as well... It's hard to get at the pump to even see where to add more fluid.
One of you asked me for my emal to send the pdf for the tabs... I greatly appreciate it.. it's weisbeker@yahoo.ca....
Right now she's in winter storage and partially under snow so it's a bit to get the manufacturer of the tabs, and pump... but will try to get up there when I get back from holidays... I am leaving sat ..to places warmer than this place...
Thanks so much for your feedback and help...

 

[Jdeagro]

Re: Where are the trim tabs at full up?

I just can't take it anymore. A post on Trim Tabs I have not been involved. I am going through withdrawal.

I read somewhere that the length of the hydraulic line from the pump to the actuator should be the same. If not the actuators will react at different rates.

My $.02!

One more side note. I too have been told hundreds of times that this or that boat does not need trim tabs by "experts" at shows, dealerships, and even factories.

I feel soooo guilty now, because we have sold thousand of trim tabs to people when they did not need them. However, I am not alone, so has Bennett, Lenco, Trim Master, Volvo, Insta Trim and more. Funny thing is they all seem happy with the resulting improvements in boat handling , performance and economy. Strange, people just do not want to make the sacrifice and endure the porpoising, high bow rise, listing, poor acceleration, reduced fuel economy, and poor handling. Isn't that what makes boating fun?
The "experts" must think so, and they know best.

 

[QC]

Re: Where are the trim tabs at full up?

OK inohv8, I just sent you the Bennett manual. Some of it will apply to some other tabs as well, but it is for Bennett's specifically.

A couple of thoughts came to mind from your last post. I have some non-Bennett hydraulic tabs now. Very similar system. My tabs do not fully retract on the trailer unless I actually lift them while someone else holds the switch down (down is up). The spring in the hydraulic actuator/cylinder are simply not strong enough without water helping to push them back up . . . I would follow Bennett's troubleshooting guide where frankly the spring is not mentioned. However, I know that mine are weak and you could check by having your son push the switch for trim tab while simultaneously lifting. Works on mine if I forget to get them all of the way up before I put her on the trailer. I can also do it alone, but lifting and then hitting the switch repeatedly. Again, non-issue while underway for me, the water is my assistant . . .

Also, be very careful about using the switches, they should NEVER be used "against" each other i.e. one pushed up and the other pushed down simultaneously. That asks the pump to run opposite directions and it will blow the breaker and or fuse depending on how it's protected. Bennett makes a little electronic box thing that helps automatically block this, but if it is not installed . . .

Edit: Hey John, long time no post . . .

 

[inohv8]

Re: Where are the trim tabs at full up?

thanks for that info... I am printing all info down for when I go up to check on the boat in a couple of weeks (weather permitting)... I want to install a couiple of waterproof switches on the side of the swim platform to adjust the tilt and tabs remotely at that time and will check all movements and go from there... I really appreciate the feedback I getting, this is a first for me with tabs and I/O.. I have always been a 2 stroke bowrider nut... it's nice not to hear the engine rumbling ..

 

[QC]

Re: Where are the trim tabs at full up?

I have always been a 2 stroke bowrider nut... it's nice not to hear the engine rumbling ..

Yup. I/Os are a pain in the arse, but they are probably the best for family boating if you have sun bathers, swimmers, ever like to beach it, and like deep Vs for a good ride. Very few IBs or OBs do all that as well as an I/O. They are an engineering clusterflip, but they deliver best what momma, dadda and junior all want . . .

 

[inohv8]

Re: Where are the trim tabs at full up?

my lady wanted a cuddy but after the boat show? oh-oh..
lol

 

[Dhadley]

Re: Where are the trim tabs at full up?

John -- where ya been????