Hydrafoil, Dol-fin????

Bosts1 · #1 03-19-2008, 03:23 PM

I have my 84' V20 with a 175 yamaha. Soooooooo I was wondering if i could get some input on a hydra foil for the engine. I know on our Scout 242 sportfish we ran one. helped it out a little. But do any of you guys have one on your V's???? and do they work??? What would it improve if anything at all?? Thanks

macojoe · #2 03-19-2008, 04:31 PM

I had a 1975 V20 Cuddy with a 1986 175 Yamaha. I used a hydro foil and it helped a lot with hole shots and getting up on plane faster. I did this when it was a I/O and then after I converted it to the outboard. I have never had a motor with out one since, except for the one I have now, but I just installed trim Tabs.

tsubaki · #3 03-19-2008, 04:58 PM

They do improve imperfections due to weight imbalance, incorrect motor height and probably a couple other things I may overlook.
It is best to adjust the motor or boat ballast but they are an easy fix for minor problems.
We usually remove them on larger motors (over 40 hp) and correct the problem but if they are on smaller ones we'll just leave them on due to frequent changing circumstances.
To make it short, they do what they profess. Slightly better hole shots, slightly better load balance and slightly better stability.
If they were really needed why aren't the motor mfr's extending their plates?

bradford · #4 03-19-2008, 11:13 PM

My engine came with it when I bought it. I leave it on so that I don't have the holes in the cavitation plate. I took it off for a while and it seems the boat trims out a little better with it. Sometimes I think they probably cause a slight bit of drag.

phester · #5 03-20-2008, 06:56 AM

there are two different designs to those dolefins. One that I had looked like a birds wing and when installed it was perpendicular to the cav. plate/lower unit. I thought it worked well, a good 39.00$ upgrade. The other design is that the "fin" looks kinda like a big flat paddle that mounts sorta inline with the cav. plate. On a larger, heavier boat I somehow think the second one mentioned would work better on a v20 or similar. Can't say I like how they look, but on my little 16' slickcraft w/ 85hp v-4 'rude it made a difference for the better.

jasoncooperpcola · #6 03-21-2008, 11:17 PM

Before i sold my 83 V-20 i installed the Doel-Fins on my Johnson 150. When we took the new owners out for a test ride i had to make sure i was in the right boat! It helped out with the hole shots and even seemed to lift the stern up. But that was the only time i've been riding in the boat since I installed them. Both the motors on my 250 Sportsman have them and i cant wait to see how they make the boat handle. I just have to get all this sanding patching sanding and painting done.

Skools Out · #7 03-22-2008, 12:28 AM

Quote:

Originally Posted by tsubaki

They do improve imperfections due to weight imbalance, incorrect motor height and probably a couple other things I may overlook.
It is best to adjust the motor or boat ballast but they are an easy fix for minor problems.
We usually remove them on larger motors (over 40 hp) and correct the problem but if they are on smaller ones we'll just leave them on due to frequent changing circumstances.
To make it short, they do what they profess. Slightly better hole shots, slightly better load balance and slightly better stability.
If they were really needed why aren't the motor mfr's extending their plates?

exactly i take them off all mine too and fix the motor and weight issue so it doesn't need one. better off without one. Best to fix the boat, sometimes it's just a prop issue. if your boat gets a better hole shot with one then your motor is to high on the boat.

THEFERMANATOR · #8 03-22-2008, 10:11 AM

I had to run them on my smaller boats simply due to the weight in the transom, but don't need it on my other ones. My 13 1/2' skiff with a 25HP SUZUKI was pretty stern heavy, so the fin did the trick as there was no place to put my tanks in the bow. And the amount of negative trim made it impossible to control without one. Some boats they work pretty well on, and others they don't.

charlie_the_tuna · #9 04-26-2008, 09:27 PM

i used the doel fin my first season and took it off my second.
it going back on for my third.
it allows me to get on plane faster and seems like it improves economy.
also seems like i can back it down more and plane at slower speeds.

bcmarinamanager · #10 04-27-2008, 06:32 PM

It's helped out a lot with mine too. If you don't want to install a full set of trim tabs the Doel-fin is a good fill-in. It actually trims the ride angle quite a bit when running on plane, and it does help with hole shots. It gives a little more top end speed due to the fact that you can trim the bow out of the water better than without it.