Reply
 
Thread Tools Search this Thread
 
Old 04 July 2012, 11:51   #1
Member
 
Country: UK - England
Town: cornwall
Boat name: nothing
Make: rib eye 430
Length: 4m +
Engine: tatsu 50
MMSI: 666
Join Date: Mar 2006
Posts: 1,916
Spray from tohatsu 50 above cav plate

Diificult title sorry ,
Have recently changed boats and was forced to convert my Beloved tohatsu 50 from short to long shaft . Expensive but all has worked very well so worth it.
The long mid section has a (small cav plate / fin ) don't know what its called but above the cav plate is a another smaller cav plate /fin on the short shaft and the long shaft has 2 of these as there is one on the new mid section casting .

Anyway the second / top plate / fin is causing an anoying spray up the transom that is constantly soaking the rear tubes . Its more anoying than a problem but if its windy it can add to the spray

I am tempted to grind the dam thing off as it seems to serv no purpose its a drastic step . any ideas anyone have a tohatsu 50 long shaft that does the same

The motor is set right, height and trim etc and the boat is performing very well indeed .
__________________

__________________
ian parkes is offline   Reply With Quote
Old 04 July 2012, 13:05   #2
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
At speed, on plane, the main anti-ventilation plate (the one just above the prop) should be at the water's surface, or just below. Some say it should be clear of the water, as long as no ventilation occurs. Sounds to me like the engine is sitting too deep.

jky
__________________

__________________
jyasaki is offline   Reply With Quote
Old 04 July 2012, 13:15   #3
Member
 
Country: UK - England
Town: cornwall
Boat name: nothing
Make: rib eye 430
Length: 4m +
Engine: tatsu 50
MMSI: 666
Join Date: Mar 2006
Posts: 1,916
I know what you mean . The engine height is correct thats not the problem , the top plate thats causing the spray is above the water level , its just the water is sort of deflected off it which is causing the spray .
__________________
ian parkes is offline   Reply With Quote
Old 04 July 2012, 13:21   #4
SR4
Member
 
Country: UK - England
Make: Avon Searider
Length: 4m +
Engine: Mercury 50hp
Join Date: Jun 2012
Posts: 388
Might sound stupid but could you fit hydrofoils to deflect it?
__________________
SR4 is offline   Reply With Quote
Old 04 July 2012, 15:48   #5
Member
 
Country: UK - England
Town: cornwall
Boat name: nothing
Make: rib eye 430
Length: 4m +
Engine: tatsu 50
MMSI: 666
Join Date: Mar 2006
Posts: 1,916
if you mean those plastic whale tail things they call doel fins or something like that . NO WAY
__________________
ian parkes is offline   Reply With Quote
Old 04 July 2012, 16:03   #6
SR4
Member
 
Country: UK - England
Make: Avon Searider
Length: 4m +
Engine: Mercury 50hp
Join Date: Jun 2012
Posts: 388
OK, stick some other sh.te on it to stop it
__________________
SR4 is offline   Reply With Quote
Old 04 July 2012, 16:07   #7
Member
 
actions's Avatar
 
Country: UK - England
Town: Herne Bay
Boat name: Red May
Make: Zodiac
Length: 4m +
Engine: 40hp Honda 4 Stroke
MMSI: Is quite long
Join Date: Jun 2010
Posts: 653
Send a message via Skype™ to actions
Cheapest option



__________________
actions is offline   Reply With Quote
Old 04 July 2012, 17:14   #8
Member
 
Country: UK - England
Town: Looe
Make: Delta
Length: 4m +
Engine: Mercury
Join Date: Apr 2004
Posts: 1,335
Engine sounds to deep in the water if its kicking up spray.
__________________
Black Dog Marine
www.blackdogmarine.com
Turbodiesel is offline   Reply With Quote
Old 04 July 2012, 18:05   #9
Member
 
Country: UK - England
Town: cornwall
Boat name: nothing
Make: rib eye 430
Length: 4m +
Engine: tatsu 50
MMSI: 666
Join Date: Mar 2006
Posts: 1,916
Quote:
Originally Posted by Turbodiesel View Post
Engine sounds to deep in the water if its kicking up spray.
Hi Rob

Iam sure its at the right height , i think its the just the way the keel ends and sends a jet of water against the upper plate . Its hard to take a good look while iam driving the boat and i can't find any calm water at present

May be best if i launch at looe one day soon and get you to come and take a look . I was going to get you to check the tune of the motor sometime anyway .
__________________
ian parkes is offline   Reply With Quote
Old 05 July 2012, 08:31   #10
Member
 
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,611
I wonder if what you are seeing is water being forvced up the front of the leg whioch if that plate wasn't there would jetwash your "rudder bearing" nicely.

If it is simply upward moving water bouncing off the plate, could you bend it down a bit at the outer edge to deflect the water back down rather than out sideways? A bead of sikaflex might have the same effect?


Somewhere out here I posted a pic I got of my cav plate at speed (got a friend to drive at a steady speed, tied the (waterproof) camera to my wrist and I hung on to the A- frame and went "click - click - click ...." through the spray at what felt like slightly differnet angles.

I got 25 odd photos - three showed me what I needed to know. The rest were at best "artistic".....
__________________

__________________
9D280 is offline   Reply With Quote
Reply

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





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 17:53.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.