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Hi everyone, I have a 1978 Boston Whaler 13 sport. Do I need to put a tail on my engine because when I sit in the back and my friend sits next to me the boat doesn't plain well. the bow points up and I have to tell him to move up front to plain. i have nothing in the boat so no extra weight and I have a 30hp fourstroke.

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I prefer smart tabs to the fin but either will improve your situation. Be sure you have the best prop and mounting height for your motor first.

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Mason -

A foil should not be necessary. There are several recommendations owners have found that can make the difference.

Move some weight forward. I presume you have a battery and fuel tank in the rear of the boat. Consider moving the fuel tank forward to either under your seat or the seat in front of you.

Engine Mounting. Check that the motor is mounted at least 2 holes up. A buried engine will have a slower time-to-plane speed. See
http://www.whalercentral.com/articles...cle_id=106

Throttle technique - Four strokes have a shallow torque band compared to a 2 stroke or DFI motor. Quicker acceleration with the throttle will get you up on plane and lower the bow sooner.

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Thanks guy for the advice. I was looking into moving the gas tank to the front and the battery box up and I think Im gonna do that.

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No need to move the battery. If your engine is mounted and trimmed properly it will plane well with two men aft. Moving the fuel tank forward may help depending upon it's capacity/weight. It's also possible you're using the wrong propeller.

I would absolutely not put a "tail" on your engine.

Follow what Phil said.

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Im using the factory prop, what type of prop should I use?

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Mason, the boat works fine until you try to plane with your buddy in the boat. Have your buddy move up until you plane. That is a small boat and that is what you have to do.

I had one of those with a 20 hp engine and it was still the most fun I ever had with any boat.

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Mason,
I agree with MG56 in regards to having your buddy move forward to plane the boat and personally, I would not waste time and money relocating your battery and fuel tank as it is not enough weight to make a marked difference. 2 stroke or 4 stroke, 1 person or two, it does not matter, every 13 foot sport I have owned or ridden in has the same slow to plain issues, excessive bow rise, and not so great slower speed handling. "tails" as you call them or otherwise known as Dole Fins, Shark Fins, or a miriad of other trade names to included any other devise that mounts to the lower end of an outboard to improve planning ability also comes along with other undesirable traits such as increased porpoising, decreased top end and tougher steering. If you want to improve this type of performance on your 13, perform a site search under the main drop down box on this website for smart tabs. Myself and others on this site have had excellent results using these tabs and after having them on my last 13 foot sport and 15 foot dauntless, I can honestly say I have never had such a night and day difference in the planning and slow speed handling characteristics of a small boat for $100-$120 investment. Some on this site are weary about smart tabs as you must drill holes in your boat, but if done properly I have had no issues and neither has the owner of my old 13 foot sport which has had Smart tabs on it for 10 years now and my 15 foot Dauntless that has had them installed for 5 years.

Jim G.

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Mason,

I'm amazed that on an almost 40 year old boat you know the propeller on your boat's engine was the one supplied by the factory. I'm under the impression that Boston Whaler didn't ship boats with engines or propellers in those days. The engine choice was usually left to the buyer or the dealer.

In order to determine the best or right propeller for your engine/boat setup it is necessary to go through some owner testing. The first stage is do do what Phil suggested, starting with the recommended engine mounting location. Once that has been done, report back with the outcome and we'll see how it's going.

Having said all the above, there is nothing wrong with adding smart tabs if you don't mind a possibly unnecessary expense. Following Phil's advice could very well solve your problem.

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Mason,
With all due respect to other contributors on this thread, I believe most of them have experience with slightly bigger whalers. I would assume that your boat being powered with a 4 stroke is not the original 40 year old motor, and that what you mean by the factory prop is the one that came with the boat. I would also assume that you do not have a tachometer so changing and buying props in different pitches that are $100-$300 each probably wont tell you if any of the other issues mentioned such as prop size and engine mounting height will be more difficult to fine tune. As a rule of thumb, your engine should be mounted close to or all the way up when you are repowering a classic 13 foot sport that was originally designed for higher torque lower weight 2 stroke power. If you have no tach, get a speedometer app on your smartphone and perform some speed runs with just you and then you and your buddy on the boat. Record the top end speed at Wide Open Throttle and count how many seconds it takes you to plane out for both scenarios. If indeed you do have a tach, then record the RPM's at WOT and check the manufacturers specs to make sure you are in the, "Sweet Spot. Report back the performance and get some feedback before you go chasing your tail with everything recommended as I believe what you will find is that if the boat is setup correctly and the performance is on par with others, what your boat is suffering from is more weight from the four stroke versus original 2 stroke weight on the transom than the boat was original designed for and this is the performance issue. Again, if this proves to be the issue, which I suspect and have experienced in the past, my recommendation would still be the same.

Jim G.

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Jim,

We do have a 1981 Sport 13 with a 30 HP Mercury EFI 4 Stroke with tilt and trim. That's a pretty fair bit of weight on the transom. Our battery is mounted aft but the 6 gallon fuel tank is secured beneath the forward thwart.

With only my wife and I aboard we can ease up onto plane by gradually increasing throttle. The bow does get a bit high for a few seconds but we soon level out as RPM increases. If we immediately go from a full stop to WOT the little boat fairly jumps onto plane with almost no bow lift. I qualify this by stating the engine is tucked under the hull fully until we trim out and reduce throttle as speed increases to more than we want. With me at 175 pounds and two friends aboard weighing about 210 pounds each I only use the WOT method to achieve planing speed. We get the bow high for perhaps 3 or four seconds in that case.

We have no tabs.

We were lucky to have bought this boat with the engine installed at a good height and a stainless steel propeller that performs well.

In my experience at least one local dealer is willing to loan out propellers as long as you buy the first one. Then when testing is complete and a choice is made any price differential is resolved.

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You have a very similar setup to me, except my 4-stroke is 25hp. my boat planes well, but I am always surprised how sensitive it is to head-on wind, and waves from certain directions. I carry up to two husky adults, a 50 lb. dog, as well as fuel ( battery in the stern. Proper motor height and prop are essential, as is trim.

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Butch,
Again, respectfully, the performance you are speaking of is kind of subjective. The fact that this boat planes out fine with just one person it leads me to believe it is pretty close to a good setup or suffering from a heavier than most 4 stroke as the weights very widely. I used my 13 foot sport on Lake Michigan which even on a calm day will have 2 foot rollers, so planing quick and at even a lower speed that tabs allow can make the difference of a fun ride or launching from wave to wave and getting slammed around a lot. The amount of planning time you are describing fully loaded is not really great performance to me. If you are having to play with the throttle to have the boat plane well in certain situations and having a 4 second planning time fully loaded, and you believe your boat is setup right, then I believe you would also see a marked difference with tabs. I do agree that the boat has to be set up to perform optimally on its own, but no matter what size boat, I do not think you will find anyone who can say they put trim tabs on their boat and it performed worse. Also, in most cases, traditional tabs cost thousands to install to see the performance enhancement. These cost around $100-$125 bucks and I do believe they do or at least used to have a money back guarantee. The result is that there really is no planning time. The boat just seems to lift and accelerate with virtually no bow rise. The boat also stays on plane with more weight or if lightly loaded at a lower speed which again is better for the average conditions I am in. I have experienced these results on both 13 foot and 15 foot hulls.

Jim G.