Reply
 
Thread Tools Search this Thread
 
Old 20 June 2021, 14:54   #1
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Ribeye leaning to Port when under power

Hi, just enjoying our recent purchase of a 2012 Ribeye 785s and have noticed that she is leaning over to port when under power regardless of tide/waves/wind conditionsÖ.so much so that the rear tube is bouncing in the water when we ride through slightly bigger waves. I have tried trimming right up and down and in between, but nothing seems to sort it. We have looked under the boat and cannot see any damage.

Is this to do with the propeller pitch or something else? I am a newbie so not experienced i am afraid. Thank you for any help.
__________________

__________________
Depdawg is offline   Reply With Quote
Old 20 June 2021, 14:56   #2
RIBnet supporter
 
C2 RIBS's Avatar
 
Country: UK - England
Town: Hants
Length: 8m +
Engine: 300hp plus
Join Date: Sep 2007
Posts: 3,041
Down to engine trim. Trim up at speed
__________________
C2 RIBS is offline   Reply With Quote
Old 20 June 2021, 15:33   #3
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Thank you

Thank you C2 Ribs. I will definitely make sure the engine is trimmed up when we are out this week.
__________________
Depdawg is offline   Reply With Quote
Old 20 June 2021, 15:51   #4
Member
 
Adam and Hayley's Avatar
 
Country: UK - England
Town: Leicestershire
Boat name: Bathtub
Make: Humber Ocean Pro
Length: 6m +
Engine: Honda 150
Join Date: Jul 2013
Posts: 191
Iíve had exactly the same problem as depdawg on a Humber ocean pro 6.3 150 and Iím very grateful that there appears to be an answe



Can you explain why this down to trim please?
__________________
Adam and Hayley is offline   Reply With Quote
Old 21 June 2021, 01:00   #5
Member
 
Voodoo's Avatar
 
Country: UK - England
Town: Southsea
Boat name: Voodoo
Make: Ribtec
Length: 7m +
Engine: Mercruiser 350 Mag
Join Date: Jan 2021
Posts: 33
RIBase
Torque reaction of the hull from the prop when its trimmed in too far for the speed I believe.
__________________
Voodoo is offline   Reply With Quote
Old 21 June 2021, 08:33   #6
Member
 
Country: UK - England
Town: Falmouth
Make: Ribcraft
Length: 5m +
Engine: Yam 150F
Join Date: Oct 2018
Posts: 98
If your RIB is sitting flat at rest and it's not a weight issue causing the port trim, I'd look at the skeg anode, usually there is a fin that you can trim to counteract the rotational force from the prop. As your prop rotates clockwise (going forwards) as well as providing forward thrust it also induces a rotational force. Excuse my very quickly drawn sketch but you'll see the point I'm trying to make. If you slacken the bolt off that attaches the skeg anode try rotating it a few degrees to starboard from the centreline, this should make a difference, if this improves it then trim it to stbd until you're happy with the balance. When everything is i balance the RIB should also track pretty straight once on the plane.

The up/down trim shouldn't impact port/stbd trim but I could be wrong.

Click image for larger version

Name:	IMG_5024.jpg
Views:	115
Size:	70.0 KB
ID:	137821
__________________
Pipster100 is offline   Reply With Quote
Old 21 June 2021, 14:33   #7
Member
 
Country: UK - England
Town: Waterlooville
Boat name: Tickler
Make: Halmatic P22
Length: 6m +
Engine: Inboard Diesel 240HP
MMSI: 235115642
Join Date: Sep 2015
Posts: 1,445
RIBase
Boating Performance

Quite a good article including the impact of trim on torque induced steering.
__________________
GuyC is offline   Reply With Quote
Old 21 June 2021, 16:37   #8
Member
 
gtflash's Avatar
 
Country: UK - England
Town: southampton
Boat name: TOP CAT 2
Make: Scorpion 8.1
Length: 8m +
Engine: 250hp HO
Join Date: Aug 2003
Posts: 1,694
Is your engine mounted dead centre? Is your boat weight biased port or starboard, I would always mount most of weight starboard to counteract prop torque. Battery, helm, oil etc.

As others have said over trim in can cause the port lean or an engine too low on the transom
__________________
gtflash is offline   Reply With Quote
Old 22 June 2021, 03:18   #9
Member
 
Country: UK - Scotland
Town: Isle of Lewis
Boat name: Sarah Saunders
Make: XS Ribs
Length: 6m +
Join Date: Dec 2019
Posts: 4
Could there also be some water in the hull and torque reaction then shifts it to the port side where it stays there until you come to rest?
__________________
vitalspark is offline   Reply With Quote
Old 22 June 2021, 03:40   #10
Member
 
Country: UK - England
Town: Nottinghamshire
Make: Ranieri 15
Length: 4m +
Engine: Suzuki DF50
Join Date: Jul 2016
Posts: 823
Take a look at this:
www.rib.net/forum/f45/willard 7m seaforce repower


Changing the prop reduced the dangerous torque roll. The effect must be influenced by the shape of the propeller thrust.
See also:
Propeller Basics Pt3
__________________
Limecc is offline   Reply With Quote
Old 22 June 2021, 04:42   #11
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Thanks Voodo.
__________________
Depdawg is offline   Reply With Quote
Old 22 June 2021, 04:45   #12
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Quote:
Originally Posted by Pipster100 View Post
If your RIB is sitting flat at rest and it's not a weight issue causing the port trim, I'd look at the skeg anode, usually there is a fin that you can trim to counteract the rotational force from the prop. As your prop rotates clockwise (going forwards) as well as providing forward thrust it also induces a rotational force. Excuse my very quickly drawn sketch but you'll see the point I'm trying to make. If you slacken the bolt off that attaches the skeg anode try rotating it a few degrees to starboard from the centreline, this should make a difference, if this improves it then trim it to stbd until you're happy with the balance. When everything is i balance the RIB should also track pretty straight once on the plane.

The up/down trim shouldn't impact port/stbd trim but I could be wrong.

Attachment 137821
Thanks Pipster. Your diagram and explanation are really helpful. Will try adjusting when I am down at the weekend.
__________________
Depdawg is offline   Reply With Quote
Old 22 June 2021, 04:46   #13
Member
 
Country: UK - England
Town: Frinton-on-Sea
Boat name: Covrib
Make: Highfield
Length: 5m +
Engine: Honda 100
Join Date: Aug 2020
Posts: 42
Ribeye you say, which way is the lean?https://www.facebook.com/groups/6868...9068999610791/
__________________
mhill is offline   Reply With Quote
Old 22 June 2021, 04:47   #14
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Quote:
Originally Posted by gtflash View Post
Is your engine mounted dead centre? Is your boat weight biased port or starboard, I would always mount most of weight starboard to counteract prop torque. Battery, helm, oil etc.

As others have said over trim in can cause the port lean or an engine too low on the transom
Thanks GTflash. I believe it is mounted dead centre along with batteries, helm etc.Useful to know about placing more weight on starboard too.
__________________
Depdawg is offline   Reply With Quote
Old 22 June 2021, 05:52   #15
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Quote:
Originally Posted by mhill View Post
Ribeye you say, which way is the lean?https://www.facebook.com/groups/6868...9068999610791/
Hi mhill. Thanks for the link...lmao here. The lean is to the left as in the picture on FB!! Not sure we have experienced it that bad yet...shows the importance of always wearing a kill chord!
__________________
Depdawg is offline   Reply With Quote
Old 22 June 2021, 05:53   #16
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Quote:
Originally Posted by vitalspark View Post
Could there also be some water in the hull and torque reaction then shifts it to the port side where it stays there until you come to rest?
Thanks vitalspark. Have not noticed water in the hull yet and will look out for this. Cheers.
__________________
Depdawg is offline   Reply With Quote
Old 22 June 2021, 05:56   #17
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Quote:
Originally Posted by Limecc View Post
Take a look at this:
www.rib.net/forum/f45/willard 7m seaforce repower


Changing the prop reduced the dangerous torque roll. The effect must be influenced by the shape of the propeller thrust.
See also:
Propeller Basics Pt3
Thanks Limecc. I have a spare prop so my try that out to see if there is a difference. The link is really useful-much appreciated.
__________________
Depdawg is offline   Reply With Quote
Old 22 June 2021, 05:59   #18
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Quote:
Originally Posted by GuyC View Post
Boating Performance

Quite a good article including the impact of trim on torque induced steering.
Thanks for sending this useful link GuyC. Lots to learn....
__________________
Depdawg is offline   Reply With Quote
Old 22 June 2021, 07:46   #19
Member
 
Country: UK - England
Town: Nottinghamshire
Make: Ranieri 15
Length: 4m +
Engine: Suzuki DF50
Join Date: Jul 2016
Posts: 823
Quote:
Originally Posted by Depdawg View Post
Thanks Limecc. I have a spare prop so my try that out to see if there is a difference. The link is really useful-much appreciated.
You want one with a high rake and one that's not sold as giving stern lift, this should produce a narrower cone.

Also GTflash mentioned it already, make sure the engine is set optimally as high as possible while giving no prop ventilation.
__________________
Limecc is offline   Reply With Quote
Old 22 June 2021, 11:11   #20
Member
 
Country: UK - England
Make: Ribeye
Length: 7m +
Engine: Outboard Yamaha 250
Join Date: Mar 2021
Posts: 19
Thanks everybody

Have spoken to Ribeye today and they have that the solution is to trim it to half way (on the electronic pitch gauge) and this should solve it. Will update once I have done this.

Thank you for everybodyís helpful comments and advice. Much appreciated.
__________________

__________________
Depdawg is offline   Reply With Quote
Reply

Tags
rib

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All times are GMT -5. The time now is 09:34.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.