minimum size outboard motor? - SailNet Community
Introduce Yourself Welcome to the Sailnet.com - The world's largest online sailing community! Tell us about yourself so we can get to know you.

 1Likes
  • 1 Post By TakeFive
 
LinkBack Thread Tools
post #1 of 6 Old 03-23-2018 Thread Starter
Junior Member
 
Join Date: Mar 2018
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
minimum size outboard motor?

Hi,

This posting in requesting information about the minimum size needed for an auxiliary outboard motor.

I sail a Bayliner Buccaneer 210 from a wet slip at a sailing club on a small inland lake in Texas.
This boat has a lot of freeboard which means that the outboard motor has to have a long shaft.
A British Seagull Super 40 Plus came with the boat when I bought it.
I keep the outboard in a locker under the seat and mount it only when I need it - it weighs about 30 lbs (Note that the Honda BF2.3 and the Suzuki DF2.5 also weigh 30 lbs). Unfortunately, the Super 40 Plus outboard has no reverse gear and can only swivel about +/- 60 degrees.
The consequence is that I can neither back out of the slip nor brake when coming into the slip.
However, the Super 40 Plus does have enough thrust to turn the boat into a 15 mph wind.

Several years ago, in an attempt to come up with a reverse capability, I bought an air cooled outboard that claimed to be 2.5 hp, but it did not have enough thrust to turn the boat into the wind.
Since then I have learned that what matters is the thrust delivered not the horsepower.
However, figures on thrust are hard to find whereas horespower is usually how the motors are rated.

From an article titled "Choosing an Outboard Motor For Your Dinghy" at ezinearticles.com, I did find the following information:
"A Bollard pull test showed that the Mercury 3.5hp and
Tohatsu 3.5hp were the most powerful at 90lbs of thrust
(These two engines along with the Mariner are virtually identical).
The least effective was the Honda 2.3hp at 66lbs of thrust.
In between were the Suzuki 2.5hp at 83lbs of thrust, the
Yamaha 2.5hp at 78lbs of thrust and the Parsun 2.6hp at 70 lbs of thrust."

The Super 40 Plus is rated between 2.5 and 3.5 hp, and it has been said that its thrust is 55 lbs, but the thrust figure seems low to me, based on personal experience.

So...now...trying to tap into the knowledge in the sailing community, do any of you know what the smallest outboard motor is that can turn a Buccaneer 210 into, say, a 15 mph wind?
Attached Thumbnails
buccaneer.jpg  
Bluejacket7377 is offline  
Sponsored Links
Advertisement
 
post #2 of 6 Old 03-24-2018
Above 5 knots
 
Join Date: Jun 2007
Location: East Stroudsburg, PA
Posts: 2,794
Thanks: 11
Thanked 179 Times in 172 Posts
Rep Power: 13
 
Dock
Re: minimum size outboard motor?

I ran a 2.2HP on an inland lake on my Capri 25 (larger, but lower freeboard, probably 500lbs heavier though).

in 20 knots true headwind the boat pretty much couldn't move, in 15 knots, I could do 4 knots.

The 2.2 was an old merc 2 stroke (early 90s version).. same as an old Nissan 2.2.

Later on I replaced the Merc with a 3.5HP Johnson 2 stroke, and 20 knots of wind was no problem, would get me 5 knots into a headwind.

I presently use a 3.5hp Merc 4 stroke long shaft (vintage 2016) on my Wavelength 24, probably lighter than your boat (but not by a lot, 500lbs or so). 20 knots of wind, I can get hull speed.

The 3.5hp Merc weighs in at 40lbs for the long shaft. No reverse. integral tank... For the record the Tohatsu and Merc are the same motors at this size.
To get a reverse you must go to the Merc 4hp, but the weight is 60lbs. They also have external tank connectors at that size though. I believe you can move up to an alternator too when you go 4hp or more.

MINI MOO, a 1983 Wavelength 24 - she's a fast cow!
SailingUphill is online now  
post #3 of 6 Old 03-24-2018 Thread Starter
Junior Member
 
Join Date: Mar 2018
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Re: minimum size outboard motor?

Thanks, SailingUphill, for your reply - it is useful information.

Your experience tends to make me believe that my Super 40 Plus Seagull is probably more toward the 3.5 hp end of the stated range rather than the 2.5 hp end of the state range.

The significance of this is that I probably need the thrust that can be produced produced by a 3.5 hp motor.

From the previous quote "A Bollard pull test showed that the Mercury 3.5hp and
Tohatsu 3.5hp were the most powerful at 90lbs of thrust...", I'd conclude that I need about 90 lbs of thrust.

Also, from the same quote I note "...the Suzuki 2.5hp at 83lbs of thrust...", which is almost equal to the two 3.5 hp motors, but is the same weight (30 lbs) as the Seagull.

So I am tentatively concluding that the Suzuki DF2.5 is what I need to get.

Thanks again for your help.
Bluejacket7377 is offline  
 
post #4 of 6 Old 03-25-2018
Senior Member
 
TakeFive's Avatar
 
Join Date: Oct 2009
Location: Swarthmore, PA
Posts: 4,953
Thanks: 22
Thanked 143 Times in 132 Posts
Rep Power: 10
 
Re: minimum size outboard motor?

Quote:
Originally Posted by Bluejacket7377 View Post
Thanks, SailingUphill, for your reply - it is useful information.

Your experience tends to make me believe that my Super 40 Plus Seagull is probably more toward the 3.5 hp end of the stated range rather than the 2.5 hp end of the state range.

The significance of this is that I probably need the thrust that can be produced produced by a 3.5 hp motor.

From the previous quote "A Bollard pull test showed that the Mercury 3.5hp and
Tohatsu 3.5hp were the most powerful at 90lbs of thrust...", I'd conclude that I need about 90 lbs of thrust.

Also, from the same quote I note "...the Suzuki 2.5hp at 83lbs of thrust...", which is almost equal to the two 3.5 hp motors, but is the same weight (30 lbs) as the Seagull.

So I am tentatively concluding that the Suzuki DF2.5 is what I need to get.

Thanks again for your help.
Power is power, and thrust is thrust. You're not going to get 3.5 hp performance out of a 2.5 hp motor. The laws of physics prevent that. There's no true substitute for higher power.

At a given power, you can tweak the thrust of a motor by selecting a different prop pitch, but it will always come at the expense of other performance factors. You can pick a prop that will deliver more thrust when the boat is moving slowly (typically a lower pitch prop), but suffer poor fuel economy and/or poor top speed in extended cruising use (due to over-revving). Sounds like that may be the tradeoff you're looking for. Just be aware that it's always a tradeoff, and that you'll sacrifice one factor to improve another one.

Typical motor size for a boat your size would be 3.5-6 hp.

I have the Suzuki DF2.5 on my dinghy. Overall I am happy. I like that it has a true neutral gear instead of the Honda's centrifugal clutch that can grab suddenly when you're starting the motor. I like that it's water-cooled and thus quieter than the Honda. I like that it weighs only 29 lb. I think that for some applications, 360 degree steering is better than a reverse gear because the prop is always turning in the direction it's designed to have the most thrust, so you may stop better than with a reverse gear would at the same hp.

For the Suzuki, I'd recommend always burning the gas out of the carb if you're going to leave it more than a couple days. I often go further and siphon the gas out of the tank first, then burn off the carb. The main customer complaint for this motor is from poor fuel delivery due to debris/varnish clogging the tiny fuel passages. I'm not sure it's any worse than any other small hp motor. The little motors always are finicky with debris. I have not had that problem, but I'm just barely getting started with my motor.

I'd recommend buying your motor from a brick & mortar dealer, not online. You may need the support, and if you shop around you can get just as good a price. My Suzuki was about $50 less from the dealer than the big Suzuki online outlet.
RegisteredUser likes this.

Rick S., Swarthmore, PA
USCG Certified Captain, OUPV and 50 Ton Master
ASA Certified 101/103/104/105/106



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

2001 Catalina 34MkII Tall Rig Wing Keel Breakin' Away, Universal Diesel M35B, Mantus 35 lb. anchor, sailing out of Rock Hall Landing Marina
TakeFive is offline  
post #5 of 6 Old 03-25-2018
Senior Member
 
fallard's Avatar
 
Join Date: Nov 2009
Location: Mystic
Posts: 2,283
Thanks: 17
Thanked 80 Times in 79 Posts
Rep Power: 10
 
Re: minimum size outboard motor?

The Bucaneer 210 displaces 3000#. I found a 6 hp outboard appropriate for use in our tidal currents on my 2500#, 18' catboat for 15 yrs. Sure, I could move this boat in calm conditions with a 2 hp motor, but it wasn't a serious option and I only did that once. Suggest the OP go with 6 hp.
fallard is online now  
post #6 of 6 Old 03-25-2018
Senior Member
 
Join Date: Aug 2010
Location: The Bahamas
Posts: 3,534
Thanks: 3
Thanked 135 Times in 133 Posts
Rep Power: 10
 
Re: minimum size outboard motor?

Suzuki 6hp, iirc, is 52# dry.
RegisteredUser is online now  
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

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











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
size minimum for East Coast off-shore cruising stpetersburgsailor Cruising & Liveaboard Forum 5 09-28-2009 05:53 PM
Outboard motor size finneganswake Newport 1 07-01-2009 01:52 PM
Minimum sailboat size to get two seperate sleeping quarters? duffer1960 General Discussion (sailing related) 9 08-02-2001 12:14 PM
Minimum sailboat size to get two seperate sleeping quarters? duffer1960 Boat Review and Purchase Forum 8 03-26-2001 06:44 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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

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