Like Tree0Likes

why do they tie outboards lower unit with rope?

Reply
Old 03-02-2003, 08:24 PM
  #1
Registered
Thread Starter
 
timucin's Avatar
 
Join Date: May 2002
Location: istanbul
Posts: 1,577
Default why do they tie outboards lower unit with rope?

why do they tie outboards lower unit with rope? in racing outboards?
timucin is offline  
Reply With Quote
Old 03-02-2003, 08:33 PM
  #2
Registered
Thread Starter
 
timucin's Avatar
 
Join Date: May 2002
Location: istanbul
Posts: 1,577
Default

i can understand that but
-is it necessary? or just an additional action?
timucin is offline  
Reply With Quote
Old 03-02-2003, 08:45 PM
  #3
Registered
 
mpally's Avatar
 
Join Date: Oct 2000
Location: St. Louis/ LOTO
My Boats: 36 Outlaw
Posts: 1,371
Default

Helps reduce stress on the motors and transom. Is it necessary? I don't know, but why wouldn't you use them for the extra support for the motors? I wouldn't say it is overkill.
mpally is offline  
Reply With Quote
Old 03-02-2003, 09:37 PM
  #4
Platinum Member
Platinum Member
 
Steve 1's Avatar
 
Join Date: Apr 2001
Location: Beautiful Fort Lauderdale www.cheetahcat.com
My Boats: Slippery when wet!
Posts: 10,833
Default

Tim just looking at a Mercury 2.5 you will see that the way the trim ram is mounted (vertical with the pin at the very top) that the propeller has a tremendous mechanical advantage….

Theoretically if cylinder/cylinders were mounted lower (maybe midpoint between the tilt tube and gear case) and in a horizontal position much more of the thrust loading and unloading could be assumed and dampened entirely by the hydraulics. And the need to Bungee the lower unit to negate any oscillation would not be needed!
Steve 1 is offline  
Reply With Quote
Old 03-02-2003, 10:30 PM
  #5
Platinum Member
Platinum Member
 
mcollinstn's Avatar
 
Join Date: Sep 2001
Location: tn
My Boats: 1991 F311SR1
Posts: 5,491
Default

Most of the darn outboard trim units use little pusher pins to trim the motor out. A good pull will let the motor flop up a good bit (as the tilt ram pulls out, the little trim pushers go in due to the way the hydraulics are setup.

This allows the motors to pop up if you hit something.

Race-only motors on race tunnels and such use a single center ram mounted to the gearcase as you described. They won't even TILT up all the way, they need will only trim up and down thru a given range.

If you run this setup, you don't need bungees, but with a normal setup it's a good thing to keep the motors pulled in against the trim pushers.
mcollinstn is offline  
Reply With Quote
Old 03-02-2003, 10:45 PM
  #6
AT Cult Member #3
VIP Member
 
R Addiction's Avatar
 
Join Date: Oct 2000
Location: Pa.
My Boats: '99 Active Thunder Tantrum
Posts: 20,687
Default

Check out the white bungee cords on this monster.......

Twin Johnson V-8's on a 26 Velocity!!!
R Addiction is offline  
Reply With Quote
Old 03-02-2003, 10:49 PM
  #7
AT Cult Member #3
VIP Member
 
R Addiction's Avatar
 
Join Date: Oct 2000
Location: Pa.
My Boats: '99 Active Thunder Tantrum
Posts: 20,687
Default

Sorry had to resize.......
R Addiction is offline  
Reply With Quote
Old 03-03-2003, 05:32 AM
  #8
Registered
 
SpectreBoy's Avatar
 
Join Date: Oct 2002
Location: Grove City, Ohio
Posts: 328
Default

Those are spare starters, if your original one don't work, ya just take one of those off, wrap it around the flywheel and give it a good jerk, and presto, your up and running again.
SpectreBoy is offline  
Reply With Quote
Old 03-03-2003, 09:18 AM
  #9
Official OSO boat whore
Charter Member
Trade Score: (2)
 
Join Date: Oct 2000
Location: Mequon, WI
My Boats: 8' row boat
Posts: 6,157
Default

You also sometimes see bungies off to the side of the motor. This is to help take some of the torque off the helm.
Cord is offline  
Reply With Quote
Old 03-03-2003, 09:20 AM
  #10
Platinum Member
Platinum Member
 
mcollinstn's Avatar
 
Join Date: Sep 2001
Location: tn
My Boats: 1991 F311SR1
Posts: 5,491
Default

Spectre,

Good point. I've never been able to figure out how to "rope start" a big block, but I've yanked a 2.5 Merc to life more than once...
mcollinstn is offline  
Reply With Quote
Reply

Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
PWRQWST
General Q & A
7
07-11-2006 11:32 PM
Waterfoul
General Boating Discussion
14
08-10-2004 07:54 PM
powerguy
General Q & A
2
03-05-2004 04:42 PM
SeaWeasel
General Q & A
2
01-14-2004 03:31 PM
blue thunder
General Q & A
27
03-18-2002 07:34 AM



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 On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 11:14 AM.


Copyright 2011 OffShoreOnly. All rights reserved.