What size outboard

[garryhulse1]

Hi again, got such a helpfull answer to my last post thought i would ask you experienced sailors out there another question, I am relatively new to sailing but am getting there lots to learn, I am now in a quandry as to what would be a suitable size inboard / outboard for my newly purchased Jouet Gollif long keel 22 ft yacht which i am busy refurbing someone suggested a mercury 25hp. that would run smoothly at about 7 knts at mid throttle. your valued help would be great. thanks again.

 

[chrishelen]

8 -10 hp should do it. 25hp is overkill and wont make your boat go any faster than hull speed.

 

[Tranona]

Absolutely. Your current 4hp is adequate for flat water but an 8-10 would be excellent. Look for models that are specific for sailboats a they will be long shaft and have different props and probably exhausts than those intended for use on small planing boats such as RIBs.

 

[maxi77]

From my experience boats of that size rend not to have engines over 10hp whether in or outboard. My last boat was 25ft and had 8hp inboard which gave around 6kts which was quite adequate, with my 4hp dinghy outboard which I carried on a lowering transom bracket to a make it easier to transfer to the dingy and b to have as a standby to the main engine I would get about 4.5 kts. Neither engine was what could be described as new so were probably giving below their rated output.

I really don't see you getting a 22ft long keel boat up to 7kts as this is a bit above the notional hull speed for such a boat and would have though something around the 6-8hp would be a fair bet for your boat, adequate power, and not too much weight hanging of the stern.

 

[Laundryman]

I have a 28' westerley that weighs 6 tons with a 15hp 4 stroke Mariner Bigfoot. It is more than adequate. Incidently,before this i bought a 4hp mariner sailmate 2 stroke as a short term fix. This too was surprisingly good and would make 5 knots in calm water. The secret is to buy an outboard model specific to sailing, less revs, more grunt.

 

[garryhulse1]

Thanx a lot matey,s you are all so helpfull gonna take your sound advice & go for a 8 -10 with my 4hp as a standby.

 

[VicS]

There was a similar question a few days ago.

See http://www.ybw.com/forums/showflat.php?Cat=0&Board=pbo&Number=2004992 for the replies to that

 

[graham]

I have an 8 hp Honda ob on our Coronado 25 yacht. Plenty of power at about 2/3 throttle usually. We also have a 3.5 hp tohatsu as a spare that will push the boat if needed and gets used on the dinghy.

About 6 knots is all you will get regardless of engine size,after that the stern will dig in and ther extra hp will be wasted in making a large wash.

 

[Poignard]

And you've got to consider the weight of the thing. A lot of weight on the stern will upset the trim and cause her to pitch more. Also you will have to lift it on/off sometimes.

 

[William_H]

I would suggest that you fit an adjustable height o/b bracket and try the 4HP you have.
Much depends on your sailing style. I have gone for years with virtually no use of the o/b. It has stayed at home for some years. The winds are predictable and the boat sails well. (and can be paddled.)

On the other hand if you need a motor to get out of a tricky harbour and if this might be against a strong wind then you need some grunt. Twin cyclinder o/bs are a lot smoother/ quieter than singles but are heavier. The sail drive props are a finer pitch which means higher engien revs so more noise. So I am sticking with the standard prop pitch but then there is always plenty of push from a 6HP on 21fter.
olewill

 

[retsina]

Get a 6 hp 4 stroke Tohatsu (£799) durable, light, low cost, economical and plenty of power for your boat. Any more power, the engine will be too big and heavy on the stern for the boat.

 

[jenku]

[ QUOTE ]
Get a 6 hp 4 stroke Tohatsu (£799) durable, light, low cost, economical and plenty of power for your boat. Any more power, the engine will be too big and heavy on the stern for the boat.

[/ QUOTE ]

I have a 5hp Tohatsu 2-stroke and do find that quite heavy! Is yours light really?? Maybe I am a weak person...

 

[VicS]

4 hp 4stroke Tohatsu weighs 26Kg. 5 & 6 Hp 25 kg. Presumably the 5 & 6 are less because that's the weight without an integral tank whereas the 4 includes the tank.

Presumably those are the weights of the 15" shaft models. 20" model will be more and is IMHO essential for use on a small sailing vessel.

Feature I don't like is the through hub exhaust. That gives very poor thrust astern, making it less satisfactory for manœuvring in confined spaces than one with the outlet above the prop (See the pic of my Evinrude Yachtwin in the link above).

7" pitch prop would be preferable to the 9" IMO but they don't say which comes as standard. The 9" I'd bet.

Also not mentioned I don't think on here yet is the possible need for an electrical output for battery charging. The Tech specs say 60 watt alternator available as an option but they don't say if that's a rectified (DC) output or just AC for lighting. Probably just AC in which case a charging adapter will be required for battery charging. Easy to make your own usually but manufacturers accessories are often priced in gold bars.