Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Outrage 20 porpoising fix

Posted by arthureld on 06/04/07 - 1:57 AM
#1

I finally got a 1984 Outrage 20 and I read some info that says this model can have a problem with porpoising.

I read about adjusting the height of the motor or adding a edge hydrofoil.

I will be taking the boat in for bottom paint and motor service soon so I'd like to deal with this while it's in the shop.

Can you guys please let me know what would help this?

Posted by Jeff on 06/04/07 - 4:58 AM
#2

ROGER,

CONGRATS! I would actually look into adding a set of Lenco Trim Tabs over a foil. I added them on my 22 and it was a easy 1 day project. Yes a foil will help the porpoising however, that is it. The tabs will help with the porpoising and all of the side to side trim and bow height issues that occur do to how the boat is loaded with people. It will also allow for low speed planing.

I just had the 22 out for the first time with mine and it was amazing the difference they made. The best part was the boat would plane off at 10 - 12 mph and stay on plane.

Post some pictures when you can.

Edited by Jeff on 06/04/07 - 6:34 AM

Posted by arthureld on 06/04/07 - 5:09 AM
#3

Thanks Jeff,
That is exactly the kind of info I was hoping for. :D
I actually haven't taken possession of it yet, but I will get it tonight or tomorrow.
Pics will be posted soon.

Posted by Joe Kriz on 06/04/07 - 10:36 AM
#4

Roger,

I wouldn't do anything until you test the boat out.
If you do find any problems with porpoising, then first try engine height and then propellors.

Then, and only then, would I try looking at something else....

Posted by arthureld on 06/04/07 - 11:22 AM
#5

Thanks Joe,
I did a search for trim tabs and saw your recommendations to others.
I'll take your advice and try it as is this season.
I have noticed the this one and the other one I rode in tended to lean and it would be nice to have a way to compinsate.
Also, on our 13' w/40 hp we have a thing on the motor that looks like a whale tale. I think that is to stop the porpoising too. That 13 footer jumps on plane so easy.
But I really don't have much experiance so I'll just test the new one out as is for a while. B)

Posted by Jeff Cunningham on 06/05/07 - 7:03 AM
#6

Roger,

I have a 1989 20' Outrage with a 200 HP engine and rear stern seat and I don't experience any porpoising. My batteries are in the center console. The boat does not have trim tabs or a doel fin.


Jeff

Posted by Craig on 06/05/07 - 7:51 AM
#7

Can Someone please explain the signs and symptoms of porpoising?

Posted by arthureld on 06/05/07 - 9:09 AM
#8

Craig, I think porpoising means standing on it's tail. The only reason I had some concern about it is because another site said it might be a problem.
Do you ever notice yours to seem high in the front?

Posted by Joe Kriz on 06/05/07 - 10:14 AM
#9

Porpoising is when your underway, the bow comes up, then down, then up, then down, and no matter what you do the bow keeps coming up and down.

My Outrage 17 II had a tendency to porpoise if I trimmed the engine out a little too far. I could correct it with the engine trim.
If you can't correct it with engine trim, then you need to try adjusting the height of your engine or try a different prop.
Many people and some mechanics assume they MUST put on some sort of fin on the engine or trim tabs.
NOT always true.
That is the easy way out and requires little thought process. Many times the fins will reduce overall efficiency and performance. I see far too many boats with the fin on the engine... Why?

As you can probably tell, I hate fins on an engine. I'm sure there may be a need for them for some people and some Whalers.... But not very many....

Posted by Jeff Cunningham on 06/05/07 - 10:24 AM
#10

I failed to mention that my engine is mounted in the third set of holes.

Jeff

Posted by Joe Kriz on 06/05/07 - 10:52 AM
#11

Jeff,

When I got my Outrage 22' Cuddy, the engine was mounted in the 2nd hole up. The engine was too low because the cavitation plate was creating too much spray. I raised the engine to the 3rd hole up like yours and the boat seemed to be just right.

The Outrage Cuddy would jump right up on plane and seemed to perform properly.

Posted by Craig on 06/05/07 - 11:29 AM
#12

Last year when we had our outrage 20" empowered with a 2004 Yamaha two stroke 150 I inquired about the fin on the motor above the prop. The mechanic told me the fins force the bow down resulting in loss of top speed and more labor for the engine? I am sure this is unique to different setups? I have never had a problem with the boat standing on its tail or rising and lowering while underway. If at all, bow rise happens minimally and can be corrected with the trim of the motor.