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).
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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.

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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!
Dan Mejak
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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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Re: 5hp motor DS II

Postby Quiggers73 » Sat May 25, 2024 12:00 pm

This is great info as look at getting a motor.

I want something as light as possible...what are most people having success with, or is it a full spectrum ?
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Re: 5hp motor DS II

Postby MikeRog » Sun May 26, 2024 7:20 pm

Just some info

My sailboat weighs about 550# loaded
I use a Minkota 30# thrust with 5 speeds ,with a 50AH Life Po 4 Battery
The battery weighs about 13 #. No gas , no noise , lightweight , easy to set up
Gets me off the dock and back into the dock
At speed 2 & 3 I have about 90 minutes of time
Would not necessarily use it on the ocean but works well on most inland lakes

Just some info to think about

Take care
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Re: 5hp motor DS II

Postby GreenLake » Tue May 28, 2024 4:19 am

Welcome to the forum. I started out with a trolling motor. Pretty much what you describe, except that I got a saltwater version.

Even new it's one of the cheapest ways to move your boat.

Very reliable: in over 10 years I recall 2 issues. I had one battery die on me. Once. And I bent a propeller an aftermarket one intended for better performance when using the motor more like an outboard. The battery had reached it's end if life. So there was nothing I could do.

But the propeller could be eased back into shape with gentle force and gentle heat.

Occasionally charging the battery in the off season was the only maintenance.

I've "upgraded" to a motor that uses 1/3 the power and works with a small lithium battery. Not quite as quiet. Definitely more expensive but just a hint faster and waaay lighter. That's worth the extra cost to me .

With a DC to DC converter it would be possible to use one of the drop-in 12V liFePo batteries. 100Ah should give several hours. Because that motor is so efficient.

Not only are the batteries lighter, they don't need as much attention during the off-season.

I'm not fully decided to spring for the converter, but if I did, it would remove all range anxieties even for some. Of the more extensive day trips I have taken around here. While still light and easy to carry and load.
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Re: 5hp motor DS II

Postby HvB » Mon Jul 08, 2024 3:02 pm

GreenLake. I would be interested in knowing what specific electric motor you upgraded to, using it with a lithium battery now and considering a DC/DC converter with a 100AH LiFePo battery.
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Re: 5hp motor DS II

Postby GreenLake » Mon Jul 08, 2024 9:09 pm

The motor is the EP Carry. It says "optimized for boats to 13' in length and 600#". However, it works fine on a DS and I've had the founder and engineer of the company check it out on my boat. The HP rating is minimal, and the electric consumption is 1/3 of what my trolling motor took, but the thrust is at least as good, if not better. I'm very pleased with the ease of use and the light weight. This one is truly a motor to have along just in case. Deploys in seconds without hassle and without the need to get up, and does not weigh down and drag the transom.

Here is the home page: https://www.electricpaddle.com/index.html

Here is a review of the same motor by someone else on the forum: viewtopic.php?f=8&t=5936

I have met the people behind this motor and am happy to endorse them and their product.

PS: here's a discussion of battery options for the EP Carry: https://www.electricpaddle.com/battery-options.html
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Re: 5hp motor DS II

Postby tomodda » Tue Jul 09, 2024 1:54 pm

@HvB: Yes, GreenLake and I had quite the discussion about the EP Carry in the thread he links. Bottom line, it's a great AUXILIARY engine, as in it'll get you back and forth to the dock and will help along in calms. It is not an all-day cruising engine, nor is it meant to be. However, you can modify it to be an all-day engine with either a solar panel or a bigger battery. For what it is - an auxiliary - it is quite expensive, but you're paying for convenience. The EP is very light, you can store it anywhere, is nearly maintenance-free, and it ALWAYS starts. Is that worth the price to you? Is upgrading it to be a cruising engine worth it to you (there are other, even more expensive choices). I dunno, that's between you and your wallet to decide!

In the meantime, I can report that the EP Carry saved my hide once, when I broke my tabernacle and almost lost the mast: https://forum.daysailer.org/forum/viewtopic.php?f=42&t=6627. Right there it "paid for itself," as I quite value my sorry hide... :D The EP started right up and stood me out of danger, when I most needed it. Thank you, EP!
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Re: 5hp motor DS II

Postby GreenLake » Tue Jul 09, 2024 8:30 pm

Battery prices have come down, and the segment of 12V drop-ins has exploded since the EP Carry was first introduced.

The dedicated 24V battery was expensive then, but it's ridiculous now. With the offered boost converter, you add one of these 12V replacements and you have several hours of motoring.

I find the original battery sufficient for nearly all uses except if you are becalmed on long cruises. Here's an example. While that situation looked dire, it turned out, it was a false alarm.

However, I'm strongly considering adding a 100Ah 12V battery to get 1200Wh, compared to the 9.6Ah 24V battery's 220. Even with some conversion loss in the boost converter, that's around 4-5 times the range. That should make adventures like the one I subscribed possible even if the wind doesn't come back. However, if I was trying to sail an event like the Texas200 with its 50nm stages, I'd bring a 200Ah battery (and a solar panel) to be able to motor at least 1/2 stage per day, plus power some devices. (This year, the usually reliable wind failed, but even people w/o motor managed to complete, those that persevered).

For such extreme distances, I might possibly invest in a slightly more powerful electric motor, because at some point, after a few hours of this, being able to do 4.5 or 5 knots will test your patience less than doing a bit over 3 knots. Again, for shorter distances and as a backup that you expect you won't actually need except as a last resort, going a bit slower is better than not going. However, I *really* appreciate how light the EP-Carry is, and how you can operate it from a sailing (not a motoring) seating position. So, even then, I might opt for a light weight solution, with the idea that the weight penalty applies constantly, but the limited benefits only apply in very specific circumstances.
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