outboard mounts - SailNet Community
Reply
 
LinkBack Thread Tools
post #1 of 11 Old 05-17-2012 Thread Starter
Member
 
Join Date: Mar 2011
Posts: 95
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
 
outboard mounts

I am buying a new outboard, 4 stroke, to replace my older 2 stroke motor. They weigh about the same, within 5 pounds or so, but in looking through catalogs and such, many outboards are listed as being for two strokes or four strokes.
My current mount is older and while I don't know the brand or model it certainly resembles the design of current two stroke mounts,
But what is the difference between two and four stroke outboards that would suggest a different mount? Is there an inherent difference in the way they shake, or torque?
What's marketed as four stroke mounts certainly look to be more beefed up mounts.
benajah is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 11 Old 05-17-2012
Barquito
 
Barquito's Avatar
 
Join Date: Dec 2007
Location: Madison, WI
Posts: 2,245
Thanks: 0
Thanked 26 Times in 26 Posts
Rep Power: 8
 
Re: outboard mounts

If it can handle the weight, I don't see why it wouldn't work.

Bristol 27
Cirque
Barquito is offline  
Quote Quick Reply Share with Facebook
post #3 of 11 Old 05-17-2012
Broad Reachin'
 
kwaltersmi's Avatar
 
Join Date: Aug 2006
Location: Grand Rapids, Michigan
Posts: 1,927
Thanks: 1
Thanked 17 Times in 17 Posts
Rep Power: 9
 
Re: outboard mounts

The difference is weight. Generally, 4-strokes are much heavier. However there are exceptions, such as my 2hp Honda 4-stroke, which is very lightweight and is no problem for my stern rail outboard mount.

Catalina 34

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
kwaltersmi is offline  
Quote Quick Reply Share with Facebook
post #4 of 11 Old 05-17-2012 Thread Starter
Member
 
Join Date: Mar 2011
Posts: 95
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
 
outboard mounts

That eases the mind some I really was not relishing the idea of drilling more holes in my transom if a new mounts holes didn't line up
benajah is offline  
Quote Quick Reply Share with Facebook
post #5 of 11 Old 05-17-2012
Senior Member
 
mstern's Avatar
 
Join Date: May 2002
Posts: 749
Thanks: 19
Thanked 8 Times in 7 Posts
Rep Power: 14
 
Re: outboard mounts

I think it is more than the weight of the engine; according to the manufacturers, four stroke engines deliver more torque (especially at low rpms) than their two stroke cousins, and the mount has to be robust enough to deal with it. I have never been able to get a straight answer either on line or in person as to how exactly to calculate if a "two stroke" mount that can handle a 100lb engine is robust enough to handle a four stroke engine that weighs only 70 lbs.

Benajah, I share your concern with the drilling necessary to accomodate a four stroke mounting bracket; that's why when I repowered several years ago, I went with a new two stroke instead of a four. Unfortunately, you don't have that option any more as the industry abandoned small two strokes several years ago. I really think its more than the engine's weight you have to deal with; maybe a talk with the good folks at Garelick (or another manufacturer of mounts) could shed some light on this for you.

Good luck.
mstern is offline  
Quote Quick Reply Share with Facebook
post #6 of 11 Old 05-17-2012 Thread Starter
Member
 
Join Date: Mar 2011
Posts: 95
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
 
outboard mounts

Yeah it's hard to get a straight answer on it. To further confuse things I have seen some mounts advertised along the lines of "for a 15 hp 2 stroke or 10 hp 4 stroke.
Then again, the smallest mount I have seen is for a 12 hp motor which is probably what my mount is made for, and I have a tiny 22 foot boat with what will be a 6 hp motor replacing a 5 hp.
benajah is offline  
Quote Quick Reply Share with Facebook
post #7 of 11 Old 05-17-2012
Barquito
 
Barquito's Avatar
 
Join Date: Dec 2007
Location: Madison, WI
Posts: 2,245
Thanks: 0
Thanked 26 Times in 26 Posts
Rep Power: 8
 
Re: outboard mounts

I can't imagine there would be enough difference in torque between two similar powered OBs that it would change what mount you need. I would imagine that there are other forces that would be much greater, like lowering the OB too fast, side forces from waves or piers, etc. The weight of the motor does effect how difficult the motor is to raise and lower. I bought a OB motor mount designed for a larger motor on ebay and found that even with the heavy aircooled 4 stroke I had to push pretty hard to lower the motor. Sold that, and got a lighter one that was a breeze to raise and lower.

Bristol 27
Cirque
Barquito is offline  
Quote Quick Reply Share with Facebook
post #8 of 11 Old 05-17-2012
Senior Member
 
mstern's Avatar
 
Join Date: May 2002
Posts: 749
Thanks: 19
Thanked 8 Times in 7 Posts
Rep Power: 14
 
Re: outboard mounts

I just did a quick search at West Marine, and that bracket you mentioned rated as "10 hp four stroke/15 hp two stroke" looks exactly like the bracket I bought 10 years ago for my two stroke:

WEST MARINE Outboard Motor Bracket, Aluminum 10hp. (4-stroke); 15hp. (2-stroke) 85lb. 11" at West Marine

If you have a small Oday (I have a 23), this bracket will fit your OEM mounting block and transom holes. Go for it!
mstern is offline  
Quote Quick Reply Share with Facebook
post #9 of 11 Old 05-17-2012 Thread Starter
Member
 
Join Date: Mar 2011
Posts: 95
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
 
outboard mounts

This appears a lot like my current mount, but no mines not an Oday it's a Westerly 22 Cirrus something of an unusual boat in the US.
benajah is offline  
Quote Quick Reply Share with Facebook
post #10 of 11 Old 05-18-2012
Senior Member
 
tommays's Avatar
 
Join Date: Sep 2008
Posts: 4,296
Thanks: 1
Thanked 30 Times in 30 Posts
Rep Power: 7
 
Re: outboard mounts

It is about the weight as some of the BIGGER motors in the 10- to 15 HP range with electric start and tilt/trim are GIANT compared to the old 2s units

1970 Cal 29 Sea Fever

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

1981 J24 Tangent 2930
Tommays
Northport NY


If a dirty bottom slows you down what do you think it does to your boat
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
tommays is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Engine Mounts davidpm Gear & Maintenance 3 05-17-2012 08:19 AM
Engine Mounts quanyin Pacific Seacraft 0 05-03-2011 12:00 PM
BBQ Mounts alofns Gear & Maintenance 1 03-03-2010 10:15 AM
Engine Mounts winethief Gear & Maintenance 3 06-03-2009 04:41 PM
Need Engine mounts.. RDV Gear & Maintenance 2 09-05-2006 02:15 PM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome