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I purchased a 1996 15' Dauntless with a 40 HP 4S EFI Mercury. I knew the boat was under-powered but I had shopped for 3 months and ending up stealing it. I posted some hole/prop/pitch questions a couple of weeks ago and quite a few folks came back and stated they needed more information. I absolutely had to do something as the boat would not plane with 2 people topping the Toledos at 460 lbs-unless of course someone moved forward. I may have done things a little backward but after reading as much as I possibly regarding Smart Tabs I decided to give 'em a shot. I put them on yesterday and it was fairly painless despite minor obstacles with a swim ladder and a transducer.

Now....I wanna say something. For me this was a huge decision. I weighed the pros and cons from posts but there was something that kept nagging at me. How many people are going to put 12 screws in the back of their BW to hang these mickey-mouse looking pieces of tin off the back of their boat and then say geez they don't work and I shouldn't have done it? I made a commitment to myself that I would do before and after tests and then post the exact results even if I wound up looking like an idiot.

Before Smart Tab Install

With just me in the boat it would plane in 7 seconds and turn 6100 RPMs WOT. It idles at 1000. Top end trimmed out was 30 MPH.
With 2 guys at 460 aboard it wouldn't plane at all hit 29 MPH and 5100 RPMs.

After install

With me in the boat it planed in 5 seconds and hit 5800 RPMs at 29 MPH.
With me and my buddy in the boat we planed in 12 seconds hit 5100 RPMs and topped at 26.

The purpose of this novella is 2-fold. I wanted to educate others as to Smart-Tab facts for my boat but selfishly I'm asking for some prop/pitch advice. I've read a lot and as far as I'm concerned...pitch/prop surely a science. In my case...rocket science. My expert boating buddy has read books on it and still doesn't get it. He calls it black magic. The Dauntless has the factory Black Max prop pitched at 13. I am very confident the engine is optimally mounted located in the second position from the top of 5 holes. I really need to get 4 people in the boat and run some more tests because for my purposes we will occasionally have 4 on board. With 2 people I'm OK with the plane now but I just have to believe there is a better prop and want to get the most out of what I have.

Prop/pitch pin-sticking voodoo gurus... Thoughts...advice...? If it were your boat which prop would you use?

BTW I'd like to thank dauntless-n-miami for giving me confidence by posting a much more complicated ST installation on his project page.
DSQ is online now Report Post

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Hello GW1996,

Glad to read that your making progress. Yes, my trim tab install was a mission and if I would have given it much more serious thought I would have eliminated the tabs altogether. Whoever did the tab install originally literally butchered the job. When they stripped out a #10 fastener a #12 was forced into that spot. The transom assemblies were poorly sealed thus the moisture weeping when I removed the hardware.

GW 1996, I have yet to fully use my tabs as they are hydraulic (slow action and the Dauntless 15 is very sensitive to their input) fortunately my Dauntless with my current prop jumps out on plane and the 90hp helps tremendously.

Your smart tabs are always deployed and auto-adjust based on the load/force placed on them which is a very efficient method and being able to change/adjust the ram dampening is a plus. Balancing the load on deck (family and gear) has helped me a bunch.

Question for you, where is your battery located? I gather your fuel storage is located within your helm seat housing? What is your fuel capacity? If your battery is at the stern consider relocating within your console. The fuel capacity question is just to know how much extra weight are you carrying aboard.

What is the WOT RPM range for your Mercury 40 four stroke? What is your prop diameter? Is this the max diameter for that O/B? You stated a current pitch of 13 inches...correct? Remember that a single pitch change (up or down) influences your rpm by roughly 150-200 rpm's and diameter changes will also have similar performance influences. These types of adjustment/tests should be considered with no more than two occupants (preferably only one) on the vessel.

Unfortunately because you are at the lower end of rated horsepower for the Dauntless 15 and due to your boating needs a perfect (or rather appropriate) prop selection will require test and tune time which may or may not be financially feasible.

Best regards,
Angel M.

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Can you elaborate on these numbers? Can't understand that at 29mph it wasn't planing. Cant understand a 1000 rpm discrepancy with a 1 mph difference.

Also curious which actuators you chose, how many #?

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Your idle # looks wrong. Too high.

What is the prop (Make, model, size and material)?

Where is the old thread for reference?

Reads to me you have the totally wrong prop for the motor/engine/weight combination.

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It almost sounds like you are asking forgiveness instead of permission for putting the trim tabs on. No worries, they did what you needed them to do and your post about it was clear and educational. So thank you.

But you stated you bought the boat for a bargain price, at least in part because it is underpowered. I'm afraid you won't find any significant value in adjusting the height of the engine nor changing props. I think you have the boat as good as it is going to get with that power.

I'd be looking into trading the existing outboard in for more HP, even if it was for a used engine. If that is something you don't want to do I'd sell the boat as is and buy something that works for you.

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You already have many answers on this same question as is still ongoing.
http://www.whalercentral.com/forum/vi...d_id=22818

Please do not have 2 threads on the same subject as it gets confusing for many of us.
This thread is locked so go back and continue this discussion on the above thread in the link.