Outboard Size for 23ft sailboat?

snider · #1 (**permalink**) 07-23-2009

I just bought a Beneteau First 235. It has a Nissan 9.9 on it now and it didn't start when I got the boat. I havn't took it apart yet but it got me thinking about buying a new outboard. What size do some of you have and what would get if you could get what you want? I want the smallest lightest thing I can get away with. I plan to use this boat for racing and cruising around Charleston SC with maybe a longer trip here and there. What size shaft do I need? Tohatsu makes a 6hp 25" shaft that would be sweet but I really want an internal tank, to get that I have to go to a 20" 4hp motor. I'm wondering if that would work? I basically have to push off the dock and I'm sailing, the boat before my Catalina didn't even have an engine, and I sailed that thing around here for over a year like that. What are some experiences and opinions? Thanks

scottyt · #2 (**permalink**) 07-23-2009

6 hp would be the min i would want unless i was a small lake sailor. a 9.9 is over sized but sometime the wind and current will make it the perfect size

yes you want as long of a shaft as you can get

sarischipper · #3 (**permalink**) 07-23-2009

For small boats, engine power is related to boat displacement. A sailboat outboard should be a small as possible (low engine weight and correct proppellor pitch) The last one is mostly forgotten.

The formula is roughly, 4 hp per 2200lb

Then go to the internet to find a propellor calculator to determine your propellor size.

Petrol engines are mostly lighter than diesel (Tohatsu)

Good luck!!

BarryL · #4 (**permalink**) 07-23-2009

Hello,

My catalina 22 came with a long shaft Tohatsu 4 HP motor with internal tank. In flat water it would reach 6 kts. I never motored much and that motor worked great for the 1 year I owed the boat.

Good luck,
Barry

snider · #5 (**permalink**) 07-23-2009

Thanks, Barry by long shaft I suppose you mean the 20". I'm leaning toward the 4 hp Tohatsu because I like having an internal tank. the boat supposedly weighs 2500 punds. I did an online calculator that suggested a 5hp to reach hull speed. Thanks

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snider · #6 (**permalink**) 07-23-2009

Hmph, have to write 3 characters.

camaraderie · #7 (**permalink**) 07-23-2009

The problem is the currents in Charleston can be wicked...you need a bit extra there. I'd go with the 6hp. As to the shaft length...it should be measured from the top of the transom mount to the surface of the water. You may need a long (19-21" measure) or an X-long if more than 22".

Insails · #8 (**permalink**) 07-23-2009

I would go with 6hp..I have a Columbia 22 displacement 2200lbs. I use a 4hp Yamaha and wished at times I had 6hp...The 4hp can be a bit slow getting to
"Rudder Speed" some marina's are tight and its best to get enough speed fast to get rudder...Also going out or coming in against a tide can be a bit of a grind..Not another feeling in the world like having almost full throttle and no head way......You will also tire of an inboard tank should you get a few miles out and boom the wind drops to zero, the extra fuel is worth it,trust me

snider · #9 (**permalink**) 07-23-2009

Thats a good point with the thrust issue. It would be nice to have that quicker acceleration. I'm 50-50 torn between the 6 and 4. Someone mentioned a 5 that had an internal tank. The wind around here is pretty reliable. I've been sans engine on my last boat and only once the whole year had to anchor and wait for wind, there was actually wind just not enough to fight the current. I just need it for docking, when I cruise I'll carry the extra tank. Hopefully 'll have this boat for years to come so I want to make the right decision. I guess it would be better wanting less than more. Hmmm. best case scenario its perfect

Thanks for the input, getting me thinking.

retclt · #10 (**permalink**) 07-23-2009

We have an old Suzuki 8 medium (20") shaft on a Chrysler 26 (5000lbs) and hull speed is never and issue . . . unless there are waves and the boat hobby horses. Then the propeller comes out of the water repeatedly and screams. Get the longest shaft available! Honda makes a really good 5hp and 8hp with 25" shafts. I imagine the 4 stroke 5hp Honda would be more powerful than my 2 stroke 8hp Suzuki. If we keep the C26 we will buy the 9.9 (25") Honda. Btw . . . I spoke with a Coast Guard mechanic and he swears the Honda is the most dependable outboard made. I'm not married to any brand. I love our Suzuki . . . it's just too short.