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Old 29 November 2011, 23:47   #21
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Originally Posted by Rookie View Post
The trouble is, you can't actually get any technical advice from 'official' sources - you can only ever speak to salespeople, who only know how to process cash or card transactions

So far as I can find out, it is best to run an outboard at its maximum power, and the only way to ascertain a 'sensible' size of prop is by (very expensive) trial and error - the options you mention may indeed be better, but, in the 2-3hp range they are probably not available

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I'm not sure where you have gained your "ascertainment", but it is NOT best to run an outboard at its maximum power any more than it is to run any engine at full power. You will get the best economy and length of life running an outboard at 1/2 to 3/4 throttle.

You should be able to pick up a reasonably priced outboard in the 2hp-6hp range with an integral tank that will be more powerful than an electric trolling motor, will have a much greater range, and not be very noisy.

Also, most generally the stock prop that comes with the outboard is going to be fine in that size motor for whatever use you have for it. You are not looking for outstanding performance as you would in a ski boat or so. It is VERY easy to figure out what size prop is needed if per chance your motor does not run within the recommended range while at WOT. There are easy to find charts to show how much pitch increase or decrease is needed if your motor is outside the limits with the current prop at WOT. No expensive trial and error is needed.
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Old 30 November 2011, 00:15   #22
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Originally Posted by SIBer
For the 600 a Honda eu10i would cost you could get a decent flexible solar panel for a lot less.
...and use it to power some led nav lights ;-)
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Old 30 November 2011, 02:47   #23
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Hi

Great post and as said above I would like to add the value for the worlds lightest 2.3 petrol outboard at 12Kg in weight. That is not a typo but it is based on the short shaft model as the long shaft is 13kg

we then dont have batteries to be taken in and out for charging and we dont have the weight of them either. It has an internal fuel tank, air cooled, no prob issues re size (it comes with one standard size and we have never needed to change this for anyone) spare shear pins etc oh a 6 year warranty. You also have single hand centrefugal clutch for single handed controle and can set the revs so no trying to keep the twist handle in the same place for hours.

re money: happy to take less than 600.00 (sorry price list is in the office so please call if interested can deliver anywhere in the UK) and did I say the best news? Its a Honda!!!
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Old 30 November 2011, 10:48   #24
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Just bought one of these new Yamaha Electric outboards for our inflatable dinghy to get us ashore, but havent used it yet so can't really say if its any good or not! Bought of Barnet Marine for around 130 (via e-bay) Interestingly, Laurence Lock said they are made by Minn-Kota for Yamaha. The Outboard has Minn-Kota written on various parts all over the motor. Badge Engineering t its best
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Old 30 November 2011, 12:53   #25
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This is what I ended up with.

eBay - The UK's Online Marketplace..

Looks very simular to the one in the above post.

It is no longer required as I have recently bought a Petrol 4hp of a fellow ribnet member.

So if anyone would like a secondhand electric 80 collected from Ebbw Vale (Np23)
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Old 01 December 2011, 05:17   #26
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and the only way to ascertain a 'sensible' size of prop is by (very expensive) trial and error -
At the sort of Hp you are looking at the prop choice is at best going to be big or small pitch, if there is a choice!

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One of the things that I have discovered in the last couple of days googling is that electric outboard makers seem to be aware of the 'weed-cutting' issue, whereas petrolheads employ all sorts of complicated theorems about propellor pitch and diameter, versus engine speed etc, which surely don't need to trouble an aged hippy like me?

Cheers, Rookie
Have a wee crawl through the old OMC site (based in Germany, but site in English) - look at the 2,4 & 6Hp engiones. Ony some of the scanned catalougues big the feature up, but they had a "weed shedding" gearbox as an option on those engines. Prop choice - take it or leave it!

Bottom line is at displacement speeds With 2 or 4Hp the theory & fine tuning that applies to a half ton plus boat at 28 knots becomes a little irrelevant.

A small 4 stroke will be pretty quiet and smell free at the sort of speeds you are looking at. (and if you have to give a fellow canal boater a hand will stand half a chance of towng them)


Noise is also subjective. I bet the whine of an electric motor will start to grate after a while too...
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Old 01 December 2011, 09:05   #27
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Bottom line is at displacement speeds With 2 or 4Hp the theory & fine tuning that applies to a half ton plus boat at 28 knots becomes a little irrelevant.
I think you are right - I reckon 2-3hp engines are aimed mainly at people who want an uncomplicated way to get ashore from the mother-ship, and mostly, they will only need the motor briefly and occasionally, but sometimes it will be required to push a heavily loaded dinghy, possibly against wind. tide and wave

So I would guess that those motors will be optimised for precisely that kind of use

Conversely, I reckon the Minn Kota Traxxis range is optimised for slow, day-long, dawdling in still and sheltered water

The only downside is getting enough battery power on board to keep the thing running - in my original post, I was weighing up the possibility of carrying a small generator as an alternative to 2, or even possibly 3, batteries. The extra weight would not be a problem, and might even help to keep the boat nicely trimmed

Anyway, thanks for your post - I haven't even got a boat yet, and I am stuck at home with a broken ankle, with far too much time to kill!

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Old 02 December 2011, 04:29   #28
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If you are talking genny you might as well just burn the fuel in an outboard! Ballpark efficiencies: Burning fuel in engine & converting to mechanical movement - 30ish %. Converting mechanical movement to electricity - 95 ish% converting electricity back to mechanical movement- 95-ish % Then there's all the extra power you need to lug the extra weight around and the 1-ish % loss i nthe eletric controller.

It strikes me if you want electric for "proper quiet" cruising, could you twin up? At those sort of speeds & power havig the petrol O/B offset won't make a huge difference, and if you get one with a charging circuit, you then only need one battery and can use the 'leccy machine where you want to be in "stealth mode". That way it also gives you more space as your genertator is hung on the transom instead of taking up space on deck. If you are really fighting the wind, turn them both on!

Hope the ankle improves soon.
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Old 02 December 2011, 07:25   #29
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I am looking to do some exploring on our local canal...
Just to go right back to the OP...do you really need any form of 'engine'?

On our local canal and on various rivers/estuaries I use a sit on kayak, actually one of THESE.

Reliable, quiet and only needs the occasional Mars bar for fuel
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Old 02 December 2011, 11:41   #30
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Interestingly, I came very close to buying a Hobie Mirage kayak a couple of years ago - I was interested in one of the inflatables but in the end I decided that they just looked too weird for words, and also I thought the fins might struggle even more than an electric outboard with weeds and underwater shopping trolleys!

Instead, I bought a Walker Bay Airis, which uses the same dropstitch construction as the Hobies and, trust me, it's awesome. Once you've pumped it up, onlookers find it hard to believe it's an inflatable, and it paddles pretty well too

Many moons ago, I had a Tinker Star Traveller which was also awesome in it's way - we rowed on the canal, explored the East Coast Rivers under sail, and used it as a fast planing yacht tender during a memorable cruise around the Western Isles of Scotland. I sold it at Beaulieu Boat Jumble and have missed it ever since

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