# Outboard size for 20ft sailboat



## mceveritt (Mar 19, 2010)

Hi All,

Just put my boat in the water (1967 bristol corinthian, 19.5ft, 2,800lb displacement).

I currently am using a 5hp tohatsu that actually used to be on a 10ft inflatable dingy (the shaft is not long). It works, as it sits in a motor well inside the cockpit which opens essentially 10inches or so from the water line.

Issue is it is a little to big and rubs up against the back of the cockpit. This not only makes the boat vibrate, but makes scratch marks on the fiberglass. Also is cumbersome to lift out and stow while the sail is up.

I only am using the motor to get in and out of the dock, once out the sail goes up immediately.

My question is if a 2.5 hp o/b would be to small or weak to push the boat along or if I really need to go to a 3 or 4 hp range.

I am looking at a mercury 2.5 hp long shaft.

Thanks!


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## MarkCK (Jan 4, 2009)

6 hp is pretty standard for that size boat. I wouldnt want to go any smaller. You could probably get out of the slip but if you got into a bad situation you will definetely want the bigger motor.


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## 75R20 (Jun 20, 2008)

I run a Suzuki 4 hp 4 stroke, but my 20ft. boat weighs in at 1550lbs. The motor pushes my boat just fine.
Yous boat is almost double of what I weigh, so I'm not sure what you would need.
Best of luck
Kary
S/V Mariah
#49080


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## Faster (Sep 13, 2005)

I think if you're truly just getting in and out of your slip and don't plan any distance cruising that a 2.5 or 3 hp would do the job. However most engines that size have no neutral position and must be spun around for reversing. This could be a problem, but I'm not sure, depends on the arrangement around the well.

The Nissan/Tohatsu etc 3.5 at least has a neutral but would still need spinning around. In order to get reverse gear I think you'll need to go to 4 and up.


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## Starlyte (Sep 27, 2009)

My 22 weighs around 2800 and I have a 7.5
I wouldn't want to be any smaller. Especially on lake Erie.


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## dabnis (Jul 29, 2007)

Mceveritt,
Had a Coronado 25 with a well at about 4,000 lbs.. 
Long story short, had a 6hp which was marginal for San Francisco Bay. went to a 15hp, same size as the 9.9, which may have been OK,
and it really got the job done. If I was to do it over, controls in the
cockpit and electric start would be good. Don't know what your water / weather conditions are but suggest you get the strongest
motor with the longest shaft that will fit in the well. My guess is that a 6 hp
with high thrust prop and long shaft would be adequate for your boat. I agree with MarkCK's post. Sometimes there is nothing like all the thrust you can get.

Just my two cents worth, Dabnis


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## Waltthesalt (Sep 22, 2009)

I have a 3.5 on my 1200# trailer sailer it pushes it fine but doing if I were to get a new motor I'd get one that reverses and that has a separate fuel tank. Fueling a built in tank I'll invariable spill some.


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## mceveritt (Mar 19, 2010)

Thanks for the input. Guess I am going to need to find a 5 or 6 hp that fits in the well. From what I can tell though it may have to be an older engine, as the modern four strokes are a lot bigger then the similar powered older two strokes.

I really want to find motor that fits before going to a bracket on the back of the transom.


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## BarryL (Aug 21, 2003)

Hello,

For just getting in and out, a 2 Hp motor will be fine. If you planned on motoring into a current or motoring for long periods of time into a head wind, then a more powerful motor would be a good idea.

I had a 4.5 Hp on a Catalina 22 and never wished for a more power.

Barry


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## mceveritt (Mar 19, 2010)

Thanks. The 5 hp I am using now pushes her along fine. The only reason I want to get a new one is that the motor casing rubs the back of the motor well and limits me to keeping the motor in a straight line. Which is fine for going forward, but basically eliminates any possibility of reversing effectively.

Just have to keep my eyes out for a motor with a small enough casing to work with my particular well configuration.


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## oldironnut (Feb 28, 2010)

*outboard for sailboat*

I have a 22' Oday. I recently replaced my 8hp 2 stroke Suzuki with a 4 hp Tohatsu 4 stroke with f-n-r transmission (my minimum requirement). It is very convenient for docking. It has the option of instantly switching from integral tank (1.3L) to external tank with a flip of a lever. I chose the 4 stroke because-no gas/oil mix, quieter, better economy. The 4 hp has plenty of power to push my boat to within 1/2mph of the hull speed. Anything will get you in and out of the slip. Where I use the power is pushing against a strong headwind with no sails up. I haven't felt handicapped at all with the 4 hp.


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## MarkSF (Feb 21, 2011)

mceveritt said:


> Thanks. The 5 hp I am using now pushes her along fine. The only reason I want to get a new one is that the motor casing rubs the back of the motor well and limits me to keeping the motor in a straight line. Which is fine for going forward, but basically eliminates any possibility of reversing effectively.
> 
> Just have to keep my eyes out for a motor with a small enough casing to work with my particular well configuration.


Or enlarge the well. I'm not being flippant, if you have a good engine, which sounds like the ideal hp, why not move the offending wall back.

PS.if you can't turn the engine, welcome to my world - you don't have any worse reversing than I do 

PPS, why bother lifting the o/b out for sailing? The drag of that little prop is small, especially compared to your full keel! Inboard engine boats live with that drag all the time. Plus, lifting a 4 stroke and stowing it, you are asking for oil in the cylinder and a tough time starting it.


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