sf655 southwind boat porpoising

hi

anyone own a sf655 southwind?

can anyone help with poroising problems?

i have a southwind sf655 with the 200hp yammy on the back with a hydro foil on the donk as well.

when in a little bit of choppy weather i can only get about 20knts befor it starts to porpoise(bounce at the front) with the motor trimmed all the way down. when you fill the live wells this gets worse.

i have been told to put a 5-8 degree  wedge in between the motor and hull to get a little bit more trim into it, but i was also told the southwind did not need this and there must be other issuses as yamaha had tested the boat all round.

i know if i slow down solves the problem but when you see the same size boats cruise pass you  there must be a way of getting a smoother ride at a faster speed.

has any one tried the wedge? or any other ideas?

thanks ron 

 


just dhu it's picture

Posts: 1081

Date Joined: 14/05/09

take fin off

Tue, 2009-12-29 19:31

I would suggest taking off the fin and not triming your motor out so far, the other thing to check would be your prop and then weight distribution in your boat, its okay getting the bow up , but your fin is trying to get it down and coming of a following sea you need a light bow but also one thats working as designed, my mates running a 200 yammy on his 655 sf not problems at all with out the fin

wide open's picture

Posts: 444

Date Joined: 24/12/09

take off the hydrofoil

Tue, 2009-12-29 19:38

take off the hydrofoil see if it solves ur problems

fisho-ron's picture

Posts: 2539

Date Joined: 26/09/09

no probs in a following sea,

Tue, 2009-12-29 19:40

no probs in a following sea, i can get the bow up a bit and its a smooth ride at the same speed, its when heading into it it gets a bit hard.

i have been told by two boat shops not to remove the foil as it will make the problem worse..

when heading out, over 20knts i cant keep the bow down, its wants to slam down on top of the waves instead of pushing through them.

if possible i would like to talk with your mate with his sf655?

cheers ron

just dhu it's picture

Posts: 1081

Date Joined: 14/05/09

call

Tue, 2009-12-29 19:49

fisho ron , i will call him as he is not a F W memeber and see if he will talk to you about your problem. hes pretty easy going so it wont be an issue, will find out if hes in town

Posts: 401

Date Joined: 01/02/09

Not enough wieght

Tue, 2009-12-29 19:50

Check your wieght distribution. Pull your esky to the front of the boat. Sounds like all your wieght is too far back. On that hydro foil, tear if off and check the quality of ride and fuel consumtion as they create some drag in the water. Another thing to check is motor position. When I got my boat I dropped the motor down by one hole so that the motor sat deeper in the water. I lost speed 42knts down to 38knts but improved the ride by 30-40%.

Andy's picture

Posts: 522

Date Joined: 08/10/05

motor height

Wed, 2009-12-30 10:10

I would look at dropping the motor one hole. is that fails look at a set of wedges for the engine.

fisho-ron's picture

Posts: 2539

Date Joined: 26/09/09

thanks andy the motor is as

Wed, 2009-12-30 11:30

thanks andy

the motor is as low as it can go already, might have to try the wedges.

cheers

Posts: 812

Date Joined: 09/10/06

mate l would be looking at

Wed, 2009-12-30 15:02

mate l would be looking at props.
some thing that gives the boat more stern lift.
a bigger bladed prop will do this for you.
ring around the prop shops and see what they say.
paul

fishy fingers's picture

Posts: 1719

Date Joined: 28/04/07

Fremantle Yamaha

Wed, 2009-12-30 17:49

Why dont you give these guy's a call from memory they used to be the agents for southwind maybe they can help.

fisho-ron's picture

Posts: 2539

Date Joined: 26/09/09

thanks fishy fingers but

Wed, 2009-12-30 18:09

thanks fishy fingers

but they have been shut down for a while now, would be good to know were they work now.

Will Trading tookover 1 part of the bussiness but no ones there knows anything about the southwinds

cheers for the info anyway

ron

Posts: 401

Date Joined: 01/02/09

Rang a mate

Thu, 2009-12-31 10:15

I asked one of my mates who fishes with a guy that has a southwind. He was saying that speed is a big factor with these types of hulls. The fella who has one has to get up quite a bit of speed to get he's "V" cutting through the water. I have to do the same with mine. Too slow and mine porposus  as well. Hope this helps mate.

fisho-ron's picture

Posts: 2539

Date Joined: 26/09/09

took the boat out today for

Fri, 2010-01-01 20:52

took the boat out today for some testing,  with the foil on and placed all weight up front as far as poss i got 38knts@5200rpm, and definatly a better ride with the extra weight forward.

with the foil removed at wot 43knts@5600rpm but found it to be a little bit more unstable,  also to get on the plane at a slower speed was worse.

the foil definatly makes a differance for the better?

(but dont let your mates hold the bolts for the foil because they might drop them in the water?????? not mentioning any names)

thanks to Rod for the info and ideas mate, it was very helpful. i looked at raising the motor like you said but there was no spray coming of at all, so i think the motor is at the right height.

it seems that if i  play around with some extra weight forward might solve the problem.

also i am proberly expecting a little bit to much out of what i got anyway,,,,,  i just want to start fishing quicker!

thanks to everyone  

Cammos's picture

Posts: 606

Date Joined: 30/06/09

Rod @ Boatshack

Fri, 2010-01-01 21:19

Sounds like you have got him already, but if not try Rod in Joondalup. He seems to know these Southwinds. I am interested to hear what you say because I am picking up my new (2nd hand) SF20 (almost the same as SF655) next week from.......you guessed it.......Rod at Boatshack. Mine has the 200hp Yammie too, maybe we should race?

fisho-ron's picture

Posts: 2539

Date Joined: 26/09/09

hi cammos yer i was talking

Fri, 2010-01-01 21:33

hi cammos

yer i was talking to rod about your boat yesterday, he knows his stuff.

i would love to hear from you once you get it to see what you think. i think you will love it.

i have been happy with mine since i got it, i just wana go faster!!!

RACE sounds good if its out to a fishn spot.

good luck with your new boat and stay intouch.

ron

Faulkner Family's picture

Posts: 18084

Date Joined: 11/03/08

you could try it with less

Fri, 2010-01-01 23:21

you could try it with less trim and getting the front down a bit so it will cut through the water instead of bouncing off it , had a similar prob with a 18foot fraser. 

____________________________________________________________________________

RUSS and SANDY. A family that fishes together stays together

Posts: 92

Date Joined: 02/11/09

I have seen simillar problems with long narrow hulls before

Sat, 2010-01-02 14:22

I would ditch the wing and install a set of trim tabs. This will allow you to trim the motor out and drop the tabs to lift the arse..........should sort your prob. I doubt that the prop is in any way affecting .

 

Mick