"Porposing"-4.3Merc-Alpha 1

[Woody-jh]

The packaging for aftermarket "fins" says that it will solve "porpoising" (bow lift), and that "fins" provide faster planing to benefit skiers and tubers. My 1995 Regal (4.3Merc, Alpha 1) has those problems. I make sure that I distribute the weight of my passengers to help the cause, but until the speed is up and the boat planed, there is only so much I can do.
Question: Do the fins work? I am reluctant to drill holes into the outdrive...holes that Mercruiser didn't put there in the first place. Thanks
(PS: If there is another forum that I should be in, let me know- I didn't see it on the list)

 

[Sherminator]

Re: "Porposing"-4.3Merc-Alpha 1

the fin does help with bow lift and help get on plane a little faster. however you can still porpoise if you have too much trim.

porpoising is when the bow of the boat keeps going up and down and up and down when on plane, all i do when that happens i trim the motor down a little bit and it goes away.

 

[ziggy]

Re: "Porposing"-4.3Merc-Alpha 1

i think the consenses here will be leaning towards smart tabs.

i think the quote is friends don't let friends use hydrofoils.

i had a hydofoil, once. all it did for me was break my anti ventalation plate.

the final thought for me not useing hydrofoils was the undue pressues that are put on the drive from haveing one. just think of the stress that is put on yer drive when ya hammer it and yer bow high and that whale tale is running at 45* in the water pushin on yer drive tryin to push yer bow down.....just don't seem like the place for the pressue to by applied. smart tabs or reg. tabs cures that notion.....

holes that Mercruiser didn't put there in the first place.

that seems like a pretty good clue right there too not to use a hydrofoil too......

 

[BRG25]

Re: "Porposing"-4.3Merc-Alpha 1

My 19' Stingray with 4.3 porpoised badly when I bought it and I installed Smart Tabs. They made a dramatic improvment. I was hesitant about drilling holes in my transom but installation was straightforward. You just need to take your time and pay attention to detail.

 

[QC]

Re: "Porposing"-4.3Merc-Alpha 1

Friends don't let friends use hydrofoils . . .

Go with Smart Tabs or some other adjustable trim tab. Your transom has lots of holes in it, one that is a LOT bigger. Little ones are easy . . .

Porpoising is about weight balance, but boats are fastest right at the point of porpoise. Set the boat up (shifting weight around) so that she will porpoise slightly at WOT and full trim height. Control that with the Smart Tabs. The Smart Tabs will also give you much lower planing speeds and an amazing solid feel at low speeds. Do it. Buy them now. Don't think about it anymore