Electric outboards

lightning · 14 July 2013, 16:35

My local boat shop has some electric outboard motors at around £120.

They look alright, l was thinking of getting one to use on the canal, as it would only need to do 3mph.
Are these cheap ones worth buying? Or are they a waste of time.

The Torqeedo ones are five times the price.

lightning · 14 July 2013, 20:52

Does nobody on here use one of these types of engine?

Well, I have done some research myself and it seems the best cheap electric engine is made by a company called Minn-Kota which is apparently Yamaha.

They cost about £135 for the version I need.

However while the engine only weighs 6kg the battery weighs 19kg! So hardly any lighter than my Tohatsu 9.8!! (26kg)

The idea was to save lugging 26kg of engine around when I only need to do 3-4mph....

Can I get a lighter 60-80Ah battery than the 100 year old lead-acid technology?
It seems that 60Ah is a minimum if you want the engine to run for 3-4 hours.

Bieny · 14 July 2013, 21:15

If you want battery to be lighter, lithium is the way to go - but I don't think you'll like the price!

lightning · 15 July 2013, 08:59

I think I will just buy a lightweight petrol outboard, some of the 2hp ones are only 12kg.

As it seems from the lack of replies that there is no real interest in these electric engines on this forum, so they can't be a viable option.

Max... · 15 July 2013, 09:12

Be sure to avoid the small air cooled Honda, as noisy as a 2 stroke.

mattvolvo1 · 15 July 2013, 09:21

As far as electric outboards go the power to weight ratio is very bad! and the weight of the battery is rediculous when you work out the weight of having the likes of a new 2.5 or 3.5hp.
I agree on the comments for the honda's not only are they noisy but the smaller ones are very poor build quality! personally I would either go for a yamaha or Tohatsu bearing in mind Tohatsu make the engines for Mercury/Mariner So same engine if you go to Tohatsu just a bit cheaper!
Hope this helps a little

9D280 · 15 July 2013, 11:17

There have been a few threads on here regarding electrics.

As above, the big problem is the "fuel density".

As you have found - plenty of wee lightweight petrols out there. That 3.5Hp tohatsu has been around in various guises from 1 to 3.5Hp and I think has carried pretty much every Manufacturer;s livery at some point. (nerds feel free to correct me on the paint job comments!)

One thing to note - if you go for the super lightweight Johsorudes from the late 60s / early 70s (The ones with the open bottom case) beware if it's hanging on the back of your rib - the exposed plugs are fine if it spends the day pushing displacement craft around, the open bottom casing does however allow a lot of the spray from your main's leg into the HT leads at the spark plug so not a lot of starting then happens!

lightning · 15 July 2013, 12:11

Yes it is going to be a small outboard motor l think.

I had heard that the Honda 2hp was noisy, and l did see one in use in Scotland last week, it was a right racket!

ShinyShoe · 15 July 2013, 22:43

OK basic stuff: people on here tend to want speed so an electric motor is not really the right thing.

Small engines on here tend to be for aux's. An eelctric motor sounds at first like it might do that - no contaminated fuel issues. But the second most common cause of engine faults after fuel is electrical so you cant rely on using the rib battery.

Endurance is poor.

If you run low on fuel as long as you can get ashore you can somehow get to fuel with a can and get back to the engine.

If you turn up with a 20kg battery at the local ESSO and ask if you can plug it in they will think you've lost the plot. Then to make it worse you'd be sat there for hours while it fills up.

Even if you cant get ashore someone can easily "lend" you some fuel. Cant really lend you charge in a battery.

lightning · 16 July 2013, 09:38

Yes I see the issues now with electric engines.

The idea seemed good for the canal, as they also make almost no noise, but the need for a great big 20kg battery spoils it.

Running out of power would not be such an issue on the canal as I could row back to where we started.

Poly · 16 July 2013, 09:52

Quote:

Originally Posted by lightning

Can I get a lighter 60-80Ah battery than the 100 year old lead-acid technology?
It seems that 60Ah is a minimum if you want the engine to run for 3-4 hours.

Yes that is what the Toquedo uses which is why it is considerably more expensive! 60Ah for 4 hrs even at low speed seems very optimistic. Even assuming that you have a battery type that doesn't "mind" being run completely flat and the engine can get enough oomph from a nearly dead battery. If my mental arithmetic is right 60A is roughly 1 HP. These are good for little fishing boats on lochs/lakes where they do 10-15 minutes and then sit still for a while then a few minutes every hour and then 15 minutes to go back ashore at the end of the day. Backed up by a set of oars. I also think that to get good life from the battery you would need an expensive (fancy) charger.

lightning · 16 July 2013, 17:52

After a bit of internet investigation it looks like the Suzuki DF 2.5 four stroke outboard is the one to go for, it only weighs 12.5kg.

PeterM · 16 July 2013, 17:55

Quote:

Originally Posted by lightning

After a bit of internet investigation it looks like the Suzuki DF 2.5 four stroke outboard is the one to go for, it only weighs 12.5kg.

Had one for a few years..just brilliant little engine.

lightning · 20 July 2013, 12:02

Are the Mariner 2.5hp two stroke engines any good? There's a couple on ebay at the moment.

uncle al · 20 July 2013, 15:07

ref the electric thrusters (I used to call them egg whisks) as a rule of thumb 17pounds thrust is equal to one h/p. When they went wrong I used to put them in a corner out of the way and forget them (hated the bloody things)

clydeoutboards · 22 July 2013, 08:01

Hi

couple of things re this post

Pollys comment of

Quote:

If my mental arithmetic is right 60A is roughly 1 HP. These are good for little fishing boats on lochs/lakes where they do 10-15 minutes and then sit still for a while then a few minutes every hour and then 15 minutes to go back ashore at the end of the day. Backed up by a set of oars.

This is v v true but very understated. The rules on some of the lochs up here will not let you run any petrol engine and hence a few fishermen decided to use them as their auxiliary when sea fishing to save money and got into serious trouble.

the smaller the engine the more it suffers from getting clogged up so before you take anyone's word for it try the Honda 2.3. It is the lightest in the world, single handed control, comes with spare shear pins etc and will run for about an hour on 1 litre of fuel at full throttle. as it is also air cooled no gunk to pick up either.

re the mariner : this is the same as the tohatsu and made by Nissan along with the mercury and is a cracking wee engine. Not as light as the Honda or air cooled but not a bad wee thing.

Poly · 22 July 2013, 08:13

Quote:

Originally Posted by clydeoutboards

the smaller the engine the more it suffers from getting clogged up so before you take anyone's word for it try the Honda 2.3. It is the lightest in the world, single handed control, comes with spare shear pins etc and will run for about an hour on 1 litre of fuel at full throttle. as it is also air cooled no gunk to pick up either.

Certainly fuel efficient - I used to own one on a small dinghy and it used one 5L can of fuel the entire time I owned it! However buy yourself a set of these:

clydeoutboards · 22 July 2013, 08:25

Quote:

Originally Posted by Poly

Certainly fuel efficient - I used to own one on a small dinghy and it used one 5L can of fuel the entire time I owned it! However buy yourself a set of these:

sorry that is rubbish. we sell a huge amount of these and we dont need to raise our voices when they are on. I would also add that we have never lost a sale due to this.

The only downside I can see is that there is not a 5hp lightweight air cooled engine as we would sell lots of those as well.

mattvolvo1 · 22 July 2013, 08:44

Have to agree with Poly on this also the build quality of the wee honda is not good also personally I would stear clear!
I think most Marine engineers would agree with that and it feels great when you throw them into a skip

clydeoutboards · 22 July 2013, 11:24

I am glad the commercial guys disagree and a huge number of fishing guys leisure boaters and sailors disagree. Its also our biggest selling engine by miles and it also has the longest warranty of any of the small petrol outboard engines on the market.