5hp motor DS II

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5hp motor DS II

Postby Beach4824 » Tue Mar 09, 2021 5:18 pm

Would a 5hp be overkill on a Daysailer II?
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Re: 5hp motor DS II

Postby GreenLake » Tue Mar 09, 2021 8:49 pm

My electric outboard uses .3hp in electric energy (there are various reasons why this isn't 1:1 compatible to the way hp's are measured for a gas outboard). My trolling motor used three times as much, or ~1hp electrical energy for getting to the same speed.

Those values define the lower bound on a practical power range.

5HP in my view defines a practical upper bound. I'm not sure it's enough to get the DS to plane, and therefore you'd be limited to hull speed. From what I've seen a fully loaded DSII do with a 2.5HP outboard, my guess is that somewhere past 3.5HP you get to a point where the additional power no longer makes the boat go faster through the water. (Theoretically, if you were motoring into a gale, you might need more power to reach hull speed, because you'd have to overcome the wind resistance as well).

My take would be that if you already own a 5HP you should be able to use it, but I wouldn't recommend you purchase one new: you'll be happier the less weight you hang off your transom. (I know that a 2.5HP works if transom mounted, but don't know if a dedicated motor bracket is indicated for a more powerful outboard)

Motor recommendations depend heavily on your usage scenarios. (The way you phrased your question, it focuses narrowly on what is possible, not what might be desirable or optimal. I've tried to answer it that way, but if you are still figuring out your requirements, let us know).
~ green ~ lake ~ ~
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Re: 5hp motor DS II

Postby jalmeida51 » Wed Mar 10, 2021 10:30 pm

I agree with Green Lake if I already owned a 5 H.P. I would use it but I wouldn't go out and buy one. I use a 2 1/2 H.P. Yamaha long shaft. I have plenty of power to cut through the chop. I admit I only use it to get out of the boat yard and shut it down after I get into the harbor. The 5 will be about 20 lbs more. . So you will be hanging about 60 lbs. on your transom. My 2 1/2 weighs about 42 lbs.

4 H.P. and above have reverse gear which is nice anything below that you will have to rotate the motor for reverse.

Smaller motors like my 2 1/2 only hold about a little more than quart of fuel so I carry an extra gallon of fuel.

Tohatsu makes a 3.5 H.P. but no reverse. They also make the small motors for Mercury, Nissan and Suzuki.

John
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Re: 5hp motor DS II

Postby rrcrazy » Fri Mar 12, 2021 4:49 pm

I was always told the transom was rated for 8 HP. I've used an old Johnson 3 HP on it in the past. Gets me in and out of tight spots. I'm not looking for hull speed, just maneuvering in channels and putting up sails when needed.

I mounted a motor bracket on my DS II at one point. It was a solid one-piece design. I made it removable so I could put my cover on it. I only used to use the motor away from what was my home lake at the time. I ran four bolts through the transom and epoxied them in. Then I used stop nuts to hold it on. I felt like it worked well.

I had a standard shaft motor. On an inland lake, it pops out of the water a little. Not enough to damage it. That motor got killed on a bigger boat on Lake Erie. So I'm all for long shafts on sailboats now!

Good luck!
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Re: 5hp motor DS II

Postby Leob1 » Wed Mar 17, 2021 11:00 am

My DSII came with a Nissan 5 hp motor. It is more than enough for the lakes I sail on. Just above idle it will get the boat moving nicely. Any more than that is just more noise and a really big wake. I have since gotten a 55 lb electric, it does the same job, is a lot quieter, doesn't smell, and it lighter. If I had to go against a ripping tide the gas motor might be the better choice. As the others have said, if you have one use it. But if buying a new motor, much less than 5 hp will do.
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Re: 5hp motor DS II

Postby GreenLake » Wed Mar 17, 2021 4:03 pm

The thing about tides: if your tide runs at 2 knots you'll loose 2knots of your speed above ground. A powerful outboard can push a DS through the water at 4.5 to 5 knots, so you still make 2.5 to 3 knots progress. But if you are in a place where the tides run much faster, you'd need an outboard sized to get the DS on a plane - expensive and prohibitively heavy.

Tides can be planned for, so best to avoid an adverse tide altogether. If you sail on something that's like a channel, you might find counter currents near shore that either weaken or even reverse the effects of the main tidal stream in the center.

Sometimes, motors can be useful to get you out of the fastest tidal stream - where you can either try your luck with counter eddies or anchor in the shallows until the tide turns. For that, going across a tide, you don't need the most powerful motor.

If you have a smaller motor that can just "hold it's own" against a tide, you can motor at an angle to "ferry glide" across to the edge of the stream w/o going backward (downstream). I've used a really small trolling motor that way to get out of the fastest current to a place where I could wait things out - in that case, I only had to wait for the wind to come back, not the 6h for the tide to turn.
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