Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

Go Back   Boat Design Forums > Design > Propulsion > Sterndrives
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-01-2011, 09:59 AM
susheng999 susheng999 is offline
Junior Member
 
Join Date: Jun 2009
Rep: 10 Posts: 10
Location: CHANGZHOU CHINA
my boat can not back off! very urgent!

the boat LOA:16.5m B:4m d:0.4m, displacement: 11t engine is mercury 130hp
propeller is P15. NOW,when we drive this boat, going ahead is good.
but can not back off,we can not feel the power. i think maybe the draft is very small. could you teach me how to settle this question? thank you very much!!!
Attached Thumbnails
my boat can not back off!  very urgent!-1.jpg  my boat can not back off!  very urgent!-2.jpg  
Reply With Quote
  #2  
Old 06-01-2011, 02:53 PM
PAR's Avatar
PAR PAR is offline
Yacht Designer & Builder
 
Join Date: Nov 2003
Rep: 3125 Posts: 9,408
Location: Eustis, FL
A lot depends on the boat shape, the location of the outboard and any appendages there might be. Generally, if an outboard is setup properly, you have excellent control in reverse.

Post a picture of the aft end of the boat with the engine lowered (out of the water of course).
Reply With Quote
  #3  
Old 06-01-2011, 05:24 PM
whitepointer23 whitepointer23 is offline
Senior Member
 
Join Date: Jan 2011
Rep: 247 Posts: 655
Location: australia
trying to pull up an 11 ton boat with a 130 outboard is going to be very difficult. you have a very small prop for a boat that size. what happens with outboards is they get a lot of airated water from the thru hub exhaust when in reverse, the heavier the load the more noticeable it is. this is why it goes well in forward and not reverse. have a look at a mercury yacht auxillary reverse mod. they use a prop which slides and has vents in the back of the hub. in forward the prop slides forward and performs as normal. in reverse the prop slides back and blocks exhaust outlet and directs exhaust through vents in back of hub. this way the prop always pulls in clean water.
__________________
brendan .
Reply With Quote
  #4  
Old 06-02-2011, 08:45 AM
susheng999 susheng999 is offline
Junior Member
 
Join Date: Jun 2009
Rep: 10 Posts: 10
Location: CHANGZHOU CHINA
thank you very much!
i agree with you, the power is not enough, and the pitch is very small, now we will change big pitch and try to lower engine.
Reply With Quote
  #5  
Old 06-02-2011, 06:44 PM
whitepointer23 whitepointer23 is offline
Senior Member
 
Join Date: Jan 2011
Rep: 247 Posts: 655
Location: australia
Quote:
Originally Posted by susheng999 View Post
thank you very much!
i agree with you, the power is not enough, and the pitch is very small, now we will change big pitch and try to lower engine.
if your thru prop exhaust is the problem. you have a sterndrive so you can change to a thru hull exhaust.
__________________
brendan .
Reply With Quote
  #6  
Old 06-04-2011, 10:40 AM
susheng999 susheng999 is offline
Junior Member
 
Join Date: Jun 2009
Rep: 10 Posts: 10
Location: CHANGZHOU CHINA
Now,it is better when we use big pitch prop. we will try to change the exhoust pipe if the space enough.
A lot of Thanks for Whitepointer23 and PAR.
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
how do you fix a hook in the back end of your boat???? toocanshan81 Boat Design 1 03-31-2009 01:37 AM
A short storie about a sunken boat and how 12 guys got it back. Ravencrew Open Discussion: All Things Boats & Boating 1 10-12-2008 02:29 AM
s there a handling benefit to having a flatter back end of the boat? ncuster Wooden Boat Building and Restoration 6 06-20-2007 11:28 AM
New Magazine for Back-Yard Boat Builders Jeff Boatbuilding 3 04-18-2002 12:31 AM


All times are GMT -5. The time now is 05:13 AM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net