First thing is a 12Vdc motor needs to be a permanant magnet type and second thing is that to get 12V back out of it as a genny it will have to spin at the same or more rpms as it would run as a motor.
So if this is a 1000rpm motor it would need to spin at 1000rpms or more. If it has a gear ratio drive, it may turn or spin at lower rpm but it will take allot of torque to get it going perhaps.

Best way to test it is just spin it with another motor or in a lathe or such to find out what RPM it will make over 14V and also test the amps it's putting out. Do this into a 12V battery as a load, if you just check the loose ends of wires that's open volts and don't mean much.

My geuss (not knowing exactly what the motor is) would be it's not going to work.
And what ever you use for a wind genny it should turn to face the wind, or more like turn to face out of the wind. In a big storm winds can rip it apart if it does not furl  out of the winds at high speeds. At sail My geuss is you will hit major winds at times, and at anchor also. I think I saw2 something about an airbrake, if so you may not need to furl, but if you can build it to yaw into winds more power to you :)

Tell you what, I travel allot anyway, I would be happy to sail the ocean blue and give advice and help build a great genny at sea with you, I'm not doing much till next NOV. anyway so give me a yell :)
 About 8 months at sea and you should have plenty of power!

Search this board with a google search for garbogen, and look at posts by Jerry. If you can find a plain old garbage disposel motor where your at it should make all the power you need at anchor or at sail! I am sure far more than the 12V your mentioned.
.
nothing to lose

Changing the subject.
To know how much energy can be produced, I need to know the motor operating voltage, (the higher, the better) and the running current at maximum voltage.

The propeller needs changing and the diameter depends on the data I ask.

The new propeller may have around 30 degrees to make rotate the motor higher enough to charge the batteries when sailing.

For wind, the diameter needs to be calculated with the expected output power at a known wind velocity (meter/second) and should have a good TSR.

Let us know

The big question is, what power does it output and at what revs?
Now as an outboard it is quite tame if not sleepy in the revs department for the 12 volts in. So maybe it's designed for slower speeds and that could be a plus as a generator.
I've given it a spin.

At 1000RPM with 4.5ohm resistor I got 1.1A @ 4.9v DC (in crude test environment). Not that impressive really. Do you have a use for 4.9v?

Maybe yours is of more recent design and is more powerful?

Seeing this, I'm keeping mine as an outboard until I chip the rest of the prop to it's hub, but would be keen to hear how you go if you give one a try.

Thanks for all the comments. First of all: No, I'm not accessing the Internet through a Satellite phone. I don't know anyone with enough money to use a sat-phone for browsing the www. In some harbours (like here in Bequia), I can get wifi with a good external antenna on the boat. Some places it's free, some places it's too expensive to be worth the bother. In other harbours there is nothing, or maybe I can take my laptop ashore to an Internet café. I usually don't know what the situation will be the next place before I get there, so if you don't hear from me for a while after I leave Bequia, you'll know I don't have Internet access. Since I'm a radio ham, I can get e-mails through Winlink over HF radio even at sea, but that's a very slow system and there is no web access.

To those who want to do what I'm doing... All you need is a sailboat. Sailboats are much cheaper than houses. Your living costs will be much lower. All long term cruisers are interested in renewable energy. Using an infernal combustion engine to charge batteries is noisy and smelly, annoys the neighbours and heats up the boat. You also have to pay for the fuel, and diesel engines are not happy being run for long times in a low load application. (Just turning an alternator rather than pushing the boat).

If you come out here with a boat flying an efficient, QUIET wind generator that you built yourself, your skills will be in high demand. With quiet, I mean not only audible noise, but also RF noise. I hate the damned Air-X wind generators which are the most common on sailboats. Not only is it a pain to be anchored next to one and have to listen to the noise (particularly when it's not my batteries it's pumping amps into), but many of them put out very loud RF noise which makes HF radio communications or listening to SW broadcast radio impossible if you're anchored within 100 - 200 yards. The manufacturers know about the problem, but are not interested in fixing it.

Now to business:

The motor I have is a trolling motor. It is incomplete, but I assume it is 12V DC, permanent magnet. There are no gears. The propeller was attached direct to the shaft which looks like it is 1/2" diameter. The propeller is more hefty than some, which implies it is not right at the bottom of the scale as far as power goes. There is no cogging when turning the shaft by hand. It becomes a bit harder to turn when shorted, but not really heavy.

The speed controller etc are missing, but I have the motor and the propeller. I am unsure about the manufacturer, but there is a sticker on the motor casing that says "Whisper Drive HE - Magnaquench". There is also a sticker on the clear plastic propeller that says "Machete". The upper part (where the speed control would be) is missing, so there may have been some more identificaton there. I've searched the net, but not been able to identify it, but maybe it's the same Mercury unit Gill has?

The 4.9V / 1.1A at 1000 RPM quoted by Gill from a similar unit implies that this is a non-starter, at least for a wind application. I don't have any means of swinging it to test, as the only power tool I own is a 12V electric drill (converted from a rechargeable) which is much too slow. I also don't have any way of measuring the RPM. I was shipwrecked last year (run down by a freighter) and lost my boat and all my tools, so I'm just in the process of getting my life back together, but that's a different story. I often see boats with the Four Winds wind generator and have noticed it is quite a slow revving rotor, so chances are this won't work. It would of course be nice to find some use for the trolling motor, but the main priority is to get a functional wind generator. I have no need for it as a trolling motor. A good pair of oars work just fine for me. Keeps me young. One of my (many) other projects is to put a sailing rig on the dinghy. The gasoline powered outboard that came with the boat is for sale.

The question then would change to looking for a suggestion for a low cost DC motor that would work well with the Four Winds rotor, hub and air brake assembly I already have, and where would I look for a suitable motor out here in the Caribbean. I don't have calipers, but measuring with a tape measure, it looks like the Four Winds hub is meant for a 5/8" shaft. Garbage disposals, as suggested by nothing to lose as a source for a motor are probably not used much out here. And no, unless you're female and unattached, you can't come sailing with me for eight months. A week is about as long as I can tolerate a male friend on the boat. That's with shared costs and if you insist on eating or drinking out, you pick up my tab as well. I'm broke!

On yawing, there really is no good way of swinging a rotor that big on this boat and allowing it to yaw. There is nowhere to mount it that would not either put its weight too high, interfere with sails or rigging or put it dangerously low (within reach of arms or heads). However, that is not a great problem as the boat is normally pointing into the wind at anchor anyway. She certainly will be when the wind is strong enough to generate electricity. She does swing about a bit, maybe 30 degrees each side of the wind direction on a breezy day, but I don't think that will be a major issue. I could set the mizzen sail to keel her pointing better into the wind. Very few wind turbines will have a tail bigger than that! A cruising boat spends much more time in port than at sea, uses less energy at sea and occasionally has to run the engine at sea for other reasons, so I'm willing to live with a wind generator that does not work under sail.

Thanks again for your input. Now I just need to divert some of it into my batteries :o)

PS. Did someone move my original post from wind to mechanical just after I posted it? Confused me. I thought it had disappeared into the ether.

Regards,

Owen Morgan
Admirality Bay, Bequia

A photo of my boat can be found here:
http://www.panoramio.com/photo/737793

Quick guess work 5 ft dia with 5 tsr in a 15 mph wind should do 420 rpm(about 28 rpm per mph) and can make about 100 watts@15mph normally if generator is matched right. Does this look right guys?

I would look around and try to find a shop that will test the motor for output. Many auto parts stores have just the thing its used for bench testing alts you will just need to add a pully. If no such stores close find someone with a power drill with a known rpm. If it works even close to the output you wanted then lets play with the parts you have. Remember to adjust pully size to expected rpms for expected out put or adjust calculations for the rpms used. If it doesn't work then see if you can find out what rpm @ what wind speed  or the tsr those blades work at.

For now you have the sealed trolling motor I like that. You have the fourwinds hub and blades. Is the shaft keyed or threaded or have the flat spot for set screws? If keyed and the slots are the same size then a shim of copper tubing or stainless could be used. Soft or hard copper tubing 1/2 id can be cut out with a hacksaw for the key slot or cut or drilled for set screws. Not sure if copper in steel is good around salt water if you ever want to take it apart so you may need stainless tubing if it works. I would try soft copper tubing to experiment with and stainless if it is going to work.

My recommendation if trolling motor is no go is an F&P if you can find a used one. Being out of a washing machine it should handle moisture better than some. Jerry has some results posted with a 61" diameter here is a link to a thread with some results he had using an F&P motor.
http://www.fieldlines.com/story/2006/4/12/221445/287
Here is a good site especially for units with F&P motors. Check out Glen's lenz2 with an F&P if you don't use the fourwinds hub and blades. It should fit in the spot you wanted to put one.
http://thebackshed.com/Windmill/FORUM1/forum_topics.asp?FID=2

Sorry about your baby being sunk. May fair winds always be at your back.