Trim Tabs - Problem- 170 Please Help

[HollyAqua]

Miguel

Hey,,,don't worry about how the installation look. I just want to see how you went about it. i'm not to good with instructions (tipical  guy). If see that picture will be alot better for me.

Look forward to the picture.

Once more thank you for all your help.

Hollyaqua.

[Miguel]

OK.  Let me see what I can do in the next few days.

[Miguel]

Here is the pic you requested.  Sorry for the messy boat.  I have not used it for a couple of months...  You can see the two little black tubing coming from the actuators outside.  That is more or less the height of the top of the actuators.  As you can see it would have been almost impossible to locate them below  the deck.

[HollyAqua]

Thank you ....thank you.

This picture really helped.

You are right there is no way to run the cable below the floor.

Let me ask you, is it really worth addition the trim tabs. Maybe my boat will be ok. I can trim with the engine.

I,m going to put older Mercury 115hp., six cylinder - 1986 " tower of power" around 325Lbs.

I,m trying to keep everything to as little and lightweight as possible.  I don't know if the bow wil be heavy.

Was it a big difference once the trim tab were on your boat?

What did you feel right away with the trim tabs working.

Once more thank so so much for the picture.

Really help me.

Hollyaqua

[Miguel]

The difference is huge!!!! The way I see it, trimming with the engine is not the same as being able to trim the hull.  That way you can adjust the attitude of the boat and maintain the optimum engine trim, thus not wasting power in trying to keep the nose up (or down).  I'm sure Tom the Tabman from Bennett can expain it a lot better than me.  He helps so many people that he probably forgot about the wealth of advise he gave me on THT.
I noticed the difference right away, first time out.  Running on a chop just felt a whole lot more comfortable.  You won't regret it.  It is probably the best piece of hardware you can add to a 170 or 175.

[Tabman]

I think Miguel explained it very well!

On my Aquasport the biggest difference was being able to hold the bow down at lower speeds.  This let me run much more comfortably in a chop.  

Tom
Bennett Marine

P.S. I remember helping you Miguel  

[Blue Agave]

Tabs will make a tremendous difference.  Go with the tabs.

[RickK]

When I was cruising the Okeechobee river this past weekend in the 230 I was certainly playing around with trim and watching the speed and gal/hr meters.  The river was flat so it was a perfect test.
The thought process is that the more of the boat that is out of the water the more efficient you are making her.  I trimmed the motor up and heard the rpms come up and saw the speed come up - gal/hr went up.  So I dropped the speed a little to get down to the speed I wanted - 25mph - and had the gal/hr "down" to 20    Then I repeated the process a little more until the engine started telling me she'd had enough. I was at this point "bow high" and very little of the boat in the water.  I was not tilted or anything so life was good.
So, at this point in my cruise I started thinking I could lower the bow with the tabs (bennetts) but that would stick more of the boat in the water and create more drag, thus lowering my efficiency.  I tried it and of course all of the above happened.
As I get below 25 I start sinking into the water (coming off plane) - at about 20 I am started to "mush".  I have heard that tabs will help you stay on plane at lower speeds but I have not seen this on the 230.

If I can lower the bow sufficently with just the trim I don't see the need for tabs.  I do see the need if I have an unbalanced load and am going down the waterway tilted - I can level it out with the tabs.  In this case I am not putting more of the boat in the water, just leveling her out.
At low speeds I have not played with the tabs so I don't know if there are benefits to tabs when off-plane.

My 170 has no tabs but haven't found a time when I thought I needed them - I can stick the bow into the water with just trim.  Maybe the hulls changed a bit in the 80's?

[seabob4]

Rick,
Think about this.  You were dropping the bow with engine trim, while at the same time trying to maintain speed to keep her on plane, to maintain efficiency.  Double duty on the motor.  Now, keep her trimmed out a bit to get good prop thrust, yet drop the bow with the tabs...get my drift?

[Capt. Bob]

While I haven't had a whole lot of seat time in the 210 WAC, I did find out a few things concerning the tabs while I was down in the Keys.

I tried to bring the boat on plane (four adults and gear) with the tabs full up. I had to use more throttle and it took longer to achieve plane. That was to be expected. Using 30% starboard and 40% port  (210 seems to have a slight port list) she planes quite quickly with less throttle. Again, what I expected. What I've found is that the Yamaha 200 likes 4100 rpm with 3+ on the trim gauge and the tabs running (depending on the chop) as low as 10% s, 20% p, giving 30 mph (GPS) with a 12 gal/hr (or a little less) fuel burn.

I think the tabs are slightly over-sized for this hull so it appears that less is more when running in a light chop.

I also have the auto-tab system which when you get it set up right, works very well for long runs in stable seas. It trims movement in the boat while underway nicely.

Off plane, I've left the tabs fully retracted. I'll have to experiment with that too.

Just another do-dad that I like.

[RickK]

Rick,
Think about this.  You were dropping the bow with engine trim, while at the same time trying to maintain speed to keep her on plane, to maintain efficiency.  Double duty on the motor.  Now, keep her trimmed out a bit to get good prop thrust, yet drop the bow with the tabs...get my drift?

Yes.
It is obviously still the belly of the boat in the water that is the inefficient part - so at higher speeds I think of them as side to side levelers.  The fore / aft tilt I can handle with the engine.
As CB said it does help the boat to plane quicker but I usually forget to put them down before I launch.  I have the "joystick" model of tab control so I really never know where the tabs are     I understand how to use the joystick but usually don't mess with it unless there is a side wind that is tilting me then it dawns on me that I have tabs that I can use  

On the 230 I am usually either running full on plane or not - not usually in between, which would be like 8-22mph - that's the inefficient part of the speed range for the 230. I guess, as Tabman mentioned about control at slower speed, as the boat sinks into the water coming off plane I hadn't thought about the high bow at that time - usually I come all the way off plane and down to under 8 mph.  I guess I should try the tabs at slower speed and see the affect.

CB you're getting great fuel efficiency.  At 25mph I'm at 18 to 19 g/h (trimmed wrong and it goes up) - at 30mph I'm at 22ish - 12 g/h would be wonderful!! Must be the bottom paint on mine?  The other boats on the run this past weekend didn't seem to use anywhere near the fuel I did - even a guy with twins.  

[Capt. Bob]

CB you're getting great fuel efficiency.  At 25mph I'm at 18 to 19 g/h (trimmed wrong and it goes up) - at 30mph I'm at 22ish - 12 g/h would be wonderful!! Must be the bottom paint on mine?  The other boats on the run this past weekend didn't seem to use anywhere near the fuel I did - even a guy with twins.  

I had assumed that the Yamaha would be similar to my Evinrude in fuel consumption. The owner's manual lists 20+ gal/hr @ WOT as the motor's burn rate. The boat will run 40 mph at 5500 but with fuel costs, it will rarely see that speed. 28-30 is what I'm doing these days and getting there  (just like me) a little slower. I agree, so far the tabs have been mostly used to level the boat.

I have the position indicator also and find it helps, along with everything else, to keep the boat in proper trim.