Outboard motors; Cruising, dingy, tips, maint, & reviews

[CapnK]

Tim -

I've a 6hp 4stk Merc (Tohatsu) on my Ariel, and IMCO that'll do the job for you just fine 95+% of the time. I think 8hp would be overkill, weight-wise (and in the end of the boat, no less), with not a lot of benefit to show for it.

Currents here run 3-4 kts on a regular basis. The 6hp is plenty of engine, it's the prop that could use some help, I believe, for maneuverability as much as anything (o/b in a well doesn't handle so well at low speed). Pivoting the engine in the well seems to help with the maneuverability a lot - too big an engine would not allow you to do that.

Only time I've needed more than what I've got was in really stiff wind (25 or more sustained, w/gusts) and current (at least 2-3 kts) from the exact same direction; the 6hp with a standard prop didn't have the uumph to head straight upwind, but I was able to make way on by 'tacking', or taking the wind on the forward quarter instead of right over the bow. Had I not been intently heading to my before-mentioned hurricane hole (left a little late that time...  ;D), I would have just anchored for a while, 'til the tide slowed or changed.

I have internal arguments all the time about selling the 6, and just using my 3.5 dinghy motor, actually. :)

[CapnK]

Additionally:

IIRC, my 6hp weighs around 55-60 lbs - which means you will have 20-30 more lbs of weight in your stern with those larger motors, Tim. Gotta watch weight when it's aft on these Ariels - with their fine, fine butts  ;D, they like to squat. :)

And like CJ, I rarely use much throttle once underway. I tick along at hull speed burning about .25 gal/hour.

Longest run yet was (IIR these #'s correctly) 125 miles, took 7 gals gas, was 32 hours underway. That nets a lil over 4 kts boat speed, but take 4 hours off for breaks & drawbridges, and consider that the first 15-18 miles was into 30 kt winds, with 3-4 seas on the Cape Fear River (thankfully, I had an ebb tide to help), and it works out close enough for me. :)

[CapnK]

Hey Gus - what's it like, getting a 22' sailboat up on plane? ;D

(Yep, that's a whompin big motor!)

[Tim]

Additionally:

IIRC, my 6hp weighs around 55-60 lbs - which means you will have 20-30 more lbs of weight in your stern with those larger motors, Tim. Gotta watch weight when it's aft on these Ariels - with their fine, fine butts  ;D, they like to squat. :)

Thanks Capn K, That's what I needed to hear, "8 hp is already on the over powered side." I have a brand new 5hp for the Potter that I would  probably use if it weren't for the shift lever position, it currently had a 3.5 Nissan on it.

Tim

[CapnK]

Tim - there is a small company making an aftermarket tiller mounted engine control setup. I cannot recall the name of the company, and my Google-fu is not so strong this morning, so I don't have a link yet, but I'll tell you what I remember... I've posted about it somewhere before, here, Ariel site, or TSBB...

It is a unit that mounts to the tiller itself (tho I think you can cockpit mount it as well) that allows for remote operation of smaller outboards from different o/b makers: throttle and gear, I remember, I don't recall if it had steering or not, but I don't think it did.

Maybe that will tick a memory in someone else's brain, and they'll recall the name or the product maker. In the meanwhile, I'm doing some more searching - if I turn anything up, I'll post it. A friends bro-in-law has one on his Hunter 28, so I'll call him later today if I can't find the info elsewhere...

[CharlieJ]

Yamaha has longer cables available so you can remove the tiller from the outboard and remount it elsewhere. I've seen a tri with a Yamaha engine on the stern and the tiller mounted on the boats tiller, some 8 feet away or so. The shift and throttle are both cable driven.

[Lynx]

The problems with getting to full displacements speeds is the ABOVE water problems, like high winds and rough seas. This increase the drag thus needing more hoursepower to move the boat at speeds. As well as turnring the boat and stopping the boat.  A bigger motor will help going to windward and in heavy seas where a minimum hp outboard would send you back. The same with getting into and leaving a dock. I use my 50 hp on my Mac 26M to help move and stop the boat at the dock all the time. People are impressed. I can reverse directions so fast/hard that I have hurt myself. The weight difference in the stern is not that much of a problem as most boats are rated for 4 or more people in the cockpit.
     
       When I crossed over to Bimini my buddy boat was a MacGregor 25 and he had a 25 hp. It would not get the boat on plan but would and did keep pushing the boat into 20+ winds and 5 foot seas. He was in his 30's and in good shape but exhausted at the end of the crossing. Other displacement boats could not have done this with smaller motors.

The other advantage is with the bigger motors you can charge your batteries more/faster than with the smaller ones.

[Cmdr Pete]

I have a 8 HP Yamaha 2 stroke on my Commander (same outboard well as the Ariel). I believe it weighs the same as a 6 HP 2 stroke, and a little extra push comes in handy. 

I don't think an 8 or 9.9 4 stroke will fit in the well (although the engines seem to be getting smaller lately). Some 6 HP 4 strokes will fit.

You definitely want the ability to swivel the engine. Makes all the difference backing up.

I have the Yamaha 701 remote engine control in the cockpit. You can sometimes find them on ebay

[Captain Smollett]

Tim - there is a small company making an aftermarket tiller mounted engine control setup. I cannot recall the name of the company,

Tohatsu sells 'em for their engines; I imagine each manufacturer does likewise?

There has been some discussion about this on TSBB with, iirc, some folks showing some home-made setups.  Might be worth it to search the archives over there.

The problems with getting to full displacements speeds is the ABOVE water problems, like high winds and rough seas. This increase the drag thus needing more hoursepower to move the boat at speeds. As well as turnring the boat and stopping the boat.  A bigger motor will help going to windward and in heavy seas where a minimum hp outboard would send you back. The same with getting into and leaving a dock. I use my 50 hp on my Mac 26M to help move and stop the boat at the dock all the time. People are impressed. I can reverse directions so fast/hard that I have hurt myself. The weight difference in the stern is not that much of a problem as most boats are rated for 4 or more people in the cockpit.
     
       When I crossed over to Bimini my buddy boat was a MacGregor 25 and he had a 25 hp. It would not get the boat on plan but would and did keep pushing the boat into 20+ winds and 5 foot seas. He was in his 30's and in good shape but exhausted at the end of the crossing. Other displacement boats could not have done this with smaller motors.

The other advantage is with the bigger motors you can charge your batteries more/faster than with the smaller ones.

An apples and oranges comparison.  Those two Mac set-ups are on a completely different part of the performance spectrum than a full keeled, relatively heavy displacement cruising boat.

You are talking about a MUCH bigger difference in OB horsepower/boat weight ratio than Tim is.  He's talking about going from 6 or 8 hp to 9.9; The Ariel has a dry displacement of 5120 lbs, or lets say 2.5 tons. Your Mac is about 2860, or about 1.5 tons.  For grins, lets say that we are getting all that engine HP to water, which is a pipe dream, but the math is easier.

For the Ariel with a 6 HP, the HP/Displ ratio is 2.4 HP/ton.  Going to a 9.9 HP gives a skosh under 4 HP / ton.

Your Mac with a 50 HP has 33 HP / ton.  Shoot, even if you run at 1/4 rated HP, you are still over TWICE the HP/ton as the Ariel with the larger HP ob.

The numbers are similar for the Mac 25 - at 2100 lbs, lets call it 1 ton.  That 25 HP OB gives her an HP/Disp ratio of 25, more in the ballpark of your 50 on the Mac26 running at 3/4 throtle.

The key point is that Tim with an Ariel is NOT going to gain a whole heck of a lot in wave/wind pushing ability (I stand by my initial thesis that CURRENT makes no difference in and of itself) going from a 6 hp to a 9.9 hp (all else being equal...prop efficiency, yadda yadda, etc).  For that marginal increase in on-paper performance, he will burn more fuel and put more weight in the stern of his boat.

Let's face it: a two and a half ton boat with an outboard is a sailboat, not a "motorsailor."  It's not going to perform like a motorboat, period.  The numbers are even worse for my Alberg, at 4.5 tons with an 8 HP outboard, by the way.  I will NOT, under any circumstances, rely on that engine to get me out of trouble.  It is a convenience, nothing more.

And just out of curiosity, why was your friend motoring and not sailing?

[CapnK]

Living pretty large there, C'Pete!

Hope yer watchin yer consumption while underway, wouldn't want to see any lactose-induced sailing accidents happen!

[AdriftAtSea]

IIRC, it's called a power tiller, and they advertise in the back of GOB magazine pretty regularly.  Their website is located here:  http://powertiller.net/

Tim - there is a small company making an aftermarket tiller mounted engine control setup. I cannot recall the name of the company, and my Google-fu is not so strong this morning, so I don't have a link yet, but I'll tell you what I remember... I've posted about it somewhere before, here, Ariel site, or TSBB...

It is a unit that mounts to the tiller itself (tho I think you can cockpit mount it as well) that allows for remote operation of smaller outboards from different o/b makers: throttle and gear, I remember, I don't recall if it had steering or not, but I don't think it did.

Maybe that will tick a memory in someone else's brain, and they'll recall the name or the product maker. In the meanwhile, I'm doing some more searching - if I turn anything up, I'll post it. A friends bro-in-law has one on his Hunter 28, so I'll call him later today if I can't find the info elsewhere...

[CharlieJ]

(I stand by my initial thesis that CURRENT makes no difference in and of itself)

Agree totally- with boats like the Ariel and my Meridian, more horsepower isn't gonna give you one bit more speed through the water. Hull speed limits and if you are heading into a 5 knot current, on the Meridian you are gonna get another 1/2 knot- well MAYBE 1 more knot, before the stern starts to squat and pull up a huge wave- The hull form just won't GO any faster.

Now into a wind, yeah- then you can gain something, but most of us rarely power into THAT much wind- at least we don't.

[Tim]

Thanks to all,

The add on tiller control like a true remote control looks to me to a bit more cockpit crowding than I care for, so I will probably go for the 8 hp Yamaha with the shift on the tiller.

The actual hole that motor drops into is 13x13, Is that any smaller than the one you have in Tehani Charlie?



Meantime I may try my Honda out, putting and an extension on the shift control.

Tim

[Lynx]

I can see that there is about a 25%+ change in hp and it may not be that much of a difference. However if he went to a 20 hp with a high thrust prop/gear ratio, there would be a good deal of difference in to the wind performance and handling at the dock. the weight of the motor is a good size person and may take some beefing up of the transom.

My friend and I was crossing the Gulf Stream and had strong wind on the nose. About 1 1/2 hrs he was able to use the main to help the ride.

I try not to get into situations where I have to depends on the motor but it can make all the difference due to poor judgment on yours or somebodies else's.

[Tim]

The reality of my plans are that if I was to have to buck serious winds I would probably stay put.  :)

[Pappy Jack]

I've often thought of replacing my old 9.9 Johnson, on my old 25' Ericson(5500lbs disp.), with an electric motor but don't know how to compair OBhp with electric "lbs of thrust". Is there a secret formula or some esoteric book of comparisons that I might look up? I have two group 27 battery's but would only have to push "Perigryn" about 200 yards out and back from our slip. I know that our 9.9 is over kill and would like to save some weight on the back side. Any ideas ????

Far winds,

Pappy Jack

[Lynx]

I suggest that you get a dinghy and use the motor for it. I justed towed a 23 Compac about 500 feet with a 2 hp, no chop with about 10 mph winds without a problem.

Recharging the batteries might be a problem as well as an incomplete charge.

The small hp motors are under $ 1g. Very common on dinghies in the Bahamas now.


1 HP = 746 Watts. Volts X amps = watts. This should give you the hp rating of the motor give or take 20%.

[Pappy Jack]

Thanks Lynx,

I know about Ohm's law and that 1 hp=750 watts. Also that the efficiency rating for gas engines to electric motors is about 5 to 1 (iirc). I've been looking through WM and all they say about their motors is voltage and thrust ::). If I had something else to work with, like ohms, amps or the like, I might be able to figure it out ;). Well, I suppose I could just call Minn Kota and ask them. I talked to the people at Johnson (OMC) and they didn't know a thing about this. Oh well, thanks again for the help :).

Fair winds,

Pappy Jack

[Captain Smollett]

Hi Pappy,

The problem is that it is actually kinda hard to compare lbs thrust from an electric to engine HP on an ICE.  Part of that is due to the fact that the electrics can deliver constant torque no matter of rpm; speed through the water is another variable.  In other words, HP vs Thrust are two different things.

The conversion is not straightforward.  See for example, the following links:

Aerospaceweb.org
OnlineConversion.com

Finally, perhaps a useful page if you are considering electric power:

Electric Boat Powering

[Pappy Jack]

Hi Captn. Smollett,

Huh? I think that is just too much for this old sailors mind to comprehend ::).I did some snooping on line and found out that Min Kota makes a 2hp 48v motor that should do the job. The fly in the ointment would be the 48v power supply. That would mean four 12v battery's in series (too much weight :o). I suppose that when all is said and done, a smaller OB, say, a four or six horse would be the best and simplest way to go ;).

Fair winds,

Pappy Jack
P.S. Thank again for taking the time to help ;).