Doel-Fin ?

Doel-Fin ?

Post by Nits » Tue, 09 Feb 1999 04:00:00


Hi,

I have seen this "Doel-Fin" in the stores (Plastic/*** fin that attaches to
the outdrive above the prop).  They claim it does all sorts of wonderful things
(improves gas mileage, increases top end speed, makes you plane faster, etc.).
I am wondering if this is a bullshit complete waste of money or in fact a good
inexpensive modification.  Does anybody have any direct experience with this
thing ?  Does it do what they claim or am I a victim of marketing ?

Thanks,

 
 
 

Doel-Fin ?

Post by (phil » Tue, 09 Feb 1999 04:00:00

Quote:

>Hi,

>I have seen this "Doel-Fin" in the stores (Plastic/*** fin that attaches to
>the outdrive above the prop).  They claim it does all sorts of wonderful things
>(improves gas mileage, increases top end speed, makes you plane faster, etc.).
>I am wondering if this is a bullshit complete waste of money or in fact a good
>inexpensive modification.  Does anybody have any direct experience with this
>thing ?  Does it do what they claim or am I a victim of marketing ?

>Thanks,


I have a Stingray outfitted to my 17' 3.0L(130HP).  Up on plane
instant and works great.  Skiers are up in a heartbeat.   However, I
heard you should not use these on boats greater that 230Hp.

Works fine... last long time.

Phil

 
 
 

Doel-Fin ?

Post by FISHEYE3 » Tue, 09 Feb 1999 04:00:00

Worked wonders on my 21' starcraft aluminum CC w/95HP OB.  Reduced porpising in
rough water and added about 4 or 5 mph to the top end.  On my 25 ft Thompson
Off Shore it seemed to have no significant effect but the boat is way under
powered anyway with its 230 HP GM V-8.  It still flounders like a dying carp.
So it has been my experience that it depends on what your starting with!

 
 
 

Doel-Fin ?

Post by BikeMa » Wed, 10 Feb 1999 04:00:00

yes very worht it. use it on my 18 foot sea ray with a 135hp
 
 
 

Doel-Fin ?

Post by Steve Barne » Wed, 10 Feb 1999 04:00:00

Steve wrote; If you have trim, waste of money!!!!
 Master Marine Technician Mer. Products
Quote:

> yes very worht it. use it on my 18 foot sea ray with a 135hp

 
 
 

Doel-Fin ?

Post by Boatbas » Wed, 10 Feb 1999 04:00:00

Quote:
>Steve wrote; If you have trim, waste of money!!!!
> Master Marine Technician Mer. Products

Steve, poor advise like that won't convince me you are a Master at anything.  I
have a 1997 90 hp Mariner on one of our 19 foot  skiffs.  It certainly has full
trim.  The boat had a severe porposing problem at any positive trim setting
over 25mph.  The hull was not designed for higher speeds.  We experimented with
changing the engine height. with no avail.  I added a set of Doel-fin knock
offs that I had in the shop.  The boat can be trimmed quite a bit now without
porposing.  Top speed was increased, and the stern lift gives a smoother drier
ride.  In short, the most improvements with a absolute minimum of expense.  A
more accurate statement from you might have read:  If your boat and engine
combo works well without it, do not use the Dole-fins,  but in certain
applications, such as with poor hull designs, or overloaded, stern heavy boats,
the benifits may be tremendous.   They are certainly not cure-alls for any
situation, otherwise they would come equipped on every outboard sold.  On the
other hand, they are certainly not a waste of money for some boats even with
power trim.
 
 
 

Doel-Fin ?

Post by Jim Gall » Wed, 10 Feb 1999 04:00:00

It depends on the type of boat that you intend to use the "Doel-Fin" on.  I
used one on my 17' Larson bowrider and didn't notice any appreciable
difference in performance.  My next boat was a 23' Baretta cuddy cabin and
that boat had a great deal of bow rise coming out of the hole.  Installation
of a "Doel Fin" substantially reduced the bow rise.

Jim Gallo

Quote:

>Hi,

>I have seen this "Doel-Fin" in the stores (Plastic/*** fin that attaches
to
>the outdrive above the prop).  They claim it does all sorts of wonderful
things
>(improves gas mileage, increases top end speed, makes you plane faster,
etc.).
>I am wondering if this is a bullshit complete waste of money or in fact a
good
>inexpensive modification.  Does anybody have any direct experience with
this
>thing ?  Does it do what they claim or am I a victim of marketing ?

>Thanks,


 
 
 

Doel-Fin ?

Post by Steve Barne » Thu, 11 Feb 1999 04:00:00

Steve wrote;  I'm not trying to convince anybody about my static's, I`m stating
facts
    See i  have a prop shop , and i can try all different types of props.
    When people have to to install Doel-fins or anything else to correct the
problem, this tells me something is wrong, in the set up etc!!!!!!!!
I had the  same type of boat in last year at my place with the same problem, we try
same thing you did it made it worst, this what i did.  Put some weight to the
front, and change the prop that gave stern lift, works very well!!!!
Yes  you are right , if it works use it!!!!!!!!!!!! What i should have said may not
work on all boat types, motor set ups etc. ( In my opining this is still a band-aid
fix)
 Take care, happy boating
Master Marine Technician Mer.Products
Quote:

> >Steve wrote; If you have trim, waste of money!!!!
> > Master Marine Technician Mer. Products

> Steve, poor advise like that won't convince me you are a Master at anything.  I
> have a 1997 90 hp Mariner on one of our 19 foot  skiffs.  It certainly has full
> trim.  The boat had a severe porposing problem at any positive trim setting
> over 25mph.  The hull was not designed for higher speeds.  We experimented with
> changing the engine height. with no avail.  I added a set of Doel-fin knock
> offs that I had in the shop.  The boat can be trimmed quite a bit now without
> porposing.  Top speed was increased, and the stern lift gives a smoother drier
> ride.  In short, the most improvements with a absolute minimum of expense.  A
> more accurate statement from you might have read:  If your boat and engine
> combo works well without it, do not use the Dole-fins,  but in certain
> applications, such as with poor hull designs, or overloaded, stern heavy boats,
> the benifits may be tremendous.   They are certainly not cure-alls for any
> situation, otherwise they would come equipped on every outboard sold.  On the
> other hand, they are certainly not a waste of money for some boats even with
> power trim.

 
 
 

Doel-Fin ?

Post by hkraus » Thu, 11 Feb 1999 04:00:00

Quote:

> Steve wrote;  I'm not trying to convince anybody about my static's, I`m stating
> facts
>     See i  have a prop shop , and i can try all different types of props.
>     When people have to to install Doel-fins or anything else to correct the
> problem, this tells me something is wrong, in the set up etc!!!!!!!!
> I had the  same type of boat in last year at my place with the same problem, we try
> same thing you did it made it worst, this what i did.  Put some weight to the
> front, and change the prop that gave stern lift, works very well!!!!

What do you look for or specify in a prop that gives stern lift?
 
 
 

Doel-Fin ?

Post by User8515 » Thu, 11 Feb 1999 04:00:00

Quote:
>Steve wrote;  I'm not trying to convince anybody about my static's, I`m
>stating
>facts
>    See i  have a prop shop , and i can try all different types of props.
>    When people have to to install Doel-fins or anything else to correct the
>problem, this tells me something is wrong, in the set up etc!!!!!!!!
>I had the  same type of boat in last year at my place with the same problem,
>we try
>same thing you did it made it worst, this what i did.  Put some weight to the
>front, and change the prop that gave stern lift, works very well!!!!
>Yes  you are right , if it works use it!!!!!!!!!!!! What i should have said
>may not
>work on all boat types, motor set ups etc. ( In my opining this is still a
>band-aid
>fix)
> Take care, happy boating
>Master Marine Technician Mer.Products


I'm with you. I don't like Dole Fins. They remind me of air shocks in a car,
the wrong way to fix a saggy spring problem. I prefer to fix the problem as you
do with weight distribution, prop, trim tabs etc. Some like Dole Fins, if they
work for you ,go for it.

my $.02
Brian

 
 
 

Doel-Fin ?

Post by Steve Barne » Thu, 11 Feb 1999 04:00:00

Steve wrote; I would install hydraulic trims for your problem!!!
                   You will fine that you can control the boat better in rough
water.
                    This style will stabilize your boat better.
                    Hope this will help you.
Quote:

> >I'm with you. I don't like Dole Fins. They remind me of air shocks in a car,
> >the wrong way to fix a saggy spring problem

> The jury is still out for me. since installing them on my 20 ft Reinell 5.0L
> 190 hp V8 my time to plane seems to have improved some. However is I have a
> semi to strong sea coming to the side it seems to push my boat. It pushes it in
> a way that if it were to flip would flip into the swell. I have had it out in
> some really strong seas with this condition and flipping into the swell seemed
> possible at times. I ended navigating as if i were in very high seas. Turning
> into swells when i shouldn't have had too.

> Any suggestions
> ?

> SA

> http://www.twow.com/bluefin/mothership.html
> Help Find Rachel Newhouse Goto  http://www.gracenote.com/rachel

 
 
 

Doel-Fin ?

Post by Sma42 » Fri, 12 Feb 1999 04:00:00

Quote:
>I'm with you. I don't like Dole Fins. They remind me of air shocks in a car,
>the wrong way to fix a saggy spring problem

The jury is still out for me. since installing them on my 20 ft Reinell 5.0L
190 hp V8 my time to plane seems to have improved some. However is I have a
semi to strong sea coming to the side it seems to push my boat. It pushes it in
a way that if it were to flip would flip into the swell. I have had it out in
some really strong seas with this condition and flipping into the swell seemed
possible at times. I ended navigating as if i were in very high seas. Turning
into swells when i shouldn't have had too.

Any suggestions
?

SA

http://www.twow.com/bluefin/mothership.html
Help Find Rachel Newhouse Goto  http://www.gracenote.com/rachel

 
 
 

Doel-Fin ?

Post by JPulley4 » Fri, 12 Feb 1999 04:00:00

They work better on uder powered boats from my experince. 1st boat was a 17ft
w/90hp ob. after putting it on I would swear by them on my 2ed boat 20ft 210hp
IO I took it off after the second trip. It did help some what when pulling the
kids in the tube but I felt more vibrations (assumed from the exhuast out of
the prop) but was using the Sport 300 model that time which is longer out the
back. If your under powered, you will like it.
 
 
 

Doel-Fin ?

Post by Steve Barne » Sat, 13 Feb 1999 04:00:00

Steve wrote;  Hi  hkrause i can give you the different types of props that will, give bow

Quote:


> > Steve wrote;  I'm not trying to convince anybody about my static's, I`m stating
> > facts
> >     See i  have a prop shop , and i can try all different types of props.
> >     When people have to to install Doel-fins or anything else to correct the
> > problem, this tells me something is wrong, in the set up etc!!!!!!!!
> > I had the  same type of boat in last year at my place with the same problem, we try
> > same thing you did it made it worst, this what i did.  Put some weight to the
> > front, and change the prop that gave stern lift, works very well!!!!

> What do you look for or specify in a prop that gives stern lift?

 
 
 

Doel-Fin ?

Post by hkraus » Sat, 13 Feb 1999 04:00:00

Quote:

> Steve wrote;  Hi  hkrause i can give you the different types of props that will, give bow



> > > Steve wrote;  I'm not trying to convince anybody about my static's, I`m stating
> > > facts
> > >     See i  have a prop shop , and i can try all different types of props.
> > >     When people have to to install Doel-fins or anything else to correct the
> > > problem, this tells me something is wrong, in the set up etc!!!!!!!!
> > > I had the  same type of boat in last year at my place with the same problem, we try
> > > same thing you did it made it worst, this what i did.  Put some weight to the
> > > front, and change the prop that gave stern lift, works very well!!!!

> > What do you look for or specify in a prop that gives stern lift?

Tell me something about "stern lift" props. I really am interested. I
have a friend with an I/O that squats.

--

Harry Krause
- - - - - - - - - - - -
Arrogance is the obstruction of wisdom.