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How does an alternator on a 63 Evinrude work

M

Michael Anderson

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" I have a 63 evinrude 75 h.p.

" I have a 63 evinrude 75 h.p. outboard. The motor runs well enough, but the battery is loosing it's charge slowly and the ammeter on the dash of the boat reads that the battery is constantly being drained by the running engine.
I understand how alternators in general work, but the particulars of this setup have me confounded. There seem to be magnets on the rotor (which is also the flywheel), and there are coils on the stator. Ususally I have seen coils on both stator and rotor. Also, one of the leads from the stator runs to the coil's + side. The others go to the boat and run into a box which contains a relay module for the selectric shift, a starter relay, and some weird old electrical device that I have never seen before. The leads from the alternator (or perhaps generator) go to the strange old electrical device with which I am not familiar. This device seems to be nothing more a pair of plugs, into which the wires are run, which are threaded into metal plates. The plate labeled "+" is isolated, and the plate labeled "-" is connected to ground.
Are these strange copper plugs some kind of old diode? Is there any way I can test them? The small amount of voltage my ohmmeter produces seems to push electrons through them with equal ease in either direction, but this does not seem like enough information to base any good theories on.
Also, I don't see anything that could really regulate voltage in the whole mess. Is Voltage just a function of engine rpm? Or are my copper plugs some kind of voltage regulator while my motor actually has a generator (rather than an altertator) that produces polarized charge? "
 
"Michael..... The stators you&

"Michael..... The stators you're no doubt familiar with have the (simply put) interior revolving inside the exterior. The alternators on outboards have the exterior revolving around the interior.

Note that the alternating system puts out 20 amps.

The strange plugs that you mention are indeed diodes, 2 neg and 2 pos. They can be tested with an ohm meter simply by sliding the sleeve on the diode lead back, unpluging the diode, then hook up one ohm meter lead to the diode lead and the other meter lead to the diode threaded portion, then reverse the leads. You should get a reading in one direction and none in the other. Any variation indicates a faulty diode.

Two diodes should be screwed into the junction box itself, and the other two should be screwed into a heat zink that is insulated on each end via plastic like brackets. Look closely and you will find a weird looking fuse screwed into the lower part of that heat zink (or close to it).

Within that junction box, there should also be a transistorized voltage regulator, roughly 3" square with a black metal top.

I do have in my remaining stock... (prices quoted are new, and will be discounted greatly) a stator $199, negative $24 and positive $20 diodes, a couple fuses $11, and one transistorized voltage regulator $180. Should you need any of those items, contact me via my e-mail address so that we don't tie up this site.

Could you send me a picture of that junction box?

For regular correspondence of your engine, it would be better if we stayed on this site with this thread. Good Luck.

Joe
"
 
" Joe,
You seem to under

" Joe,
You seem to understand exactly how my wiring is set up. The transistorized voltage regulator is in the junction box. The man from whom I bought the boat told me that the junction housed relays for the electronic shifter. I am now sure that he was wrong, and that the part in question is an old Delco-Remy voltage regulator.
The situation has gotten more complicated since last posting though. I noticed when taking a careful look at the junction box that there were pieces of what looked like doorbell wire inside the junction. It turns out that whomever had last worked on the boat had spliced new wire in at the positive and negative battery connections, and run it forward to get bow and stern lights working. They had also unplugged a wiring harness. After looking over all the circuitry, I am fairly certain that the battery was connected directly to everything that worked, and the alternator was actually disconnected from the battery.
When I put everything back like it was supposed to be, I ended up with a dead short somewhere.
Thus, it seems to me that it is time to end the season and rewire the boat (especially as I need to put a float in the carb, change some gaskets, and am already using my spare prop). Do you have any suggestions on how I should do this? The old voltage regulator seems really outdated, and I would like something cheap, efficient, and above all reliable; which leads me to think that I should buy a modern solid-state replacement of some kind. But, on the other hand, the old unit worked for some forty years!
Any input you have will be greatly appreciated. I would especially like to know how hard it is to rebuild these rectifier/regulator setups, and if someone makes replacement units that are designed to take their places (you don't have one of those around... Do you?).
Thanks for all the help so far,
Michael Anderson "
 
"Michael... You may be able to

"Michael... You may be able to obtain a manual for your engine from Andrew at this site. I understand your engine wiring system due to the fact that I worked on that model when it was new. That alternating system came out on the 75hp model in 1961.

I can't tell you how to rebuild the units, but I will supply what info I can. Better to get the manual so that you'll have all the test readings, etc.

It will be impossible to find a complete replacement unit if you're speaking of a entire junction box, ready to go, UNLESS you get lucky and find it in a outboard repair shop whereas they do keep scraped engines laying around to be used for parts.

I do have some items for the engine as listed in my previous post, and I'm sure I have more than that..... just haven't looked. When you need something, let me know what it is and I'll look to see if I have it. ([email protected])

PS... It would have been better to enter your post under the topic of "Outboard" rather than "Miscellaneous". I just happened to stumble over it here, but it's okay.

Joe
"
 
" Mr. Anderson,
I have the

" Mr. Anderson,
I have the very same problem. I bought a complete boat from 1961 for a pet project. I have ordered a manual for the same motor on Ebay for $12 from austraia where it was built. just go to Ebay and type in "search" 1961 Evinrude 75HP. These idems seem hard to find in working order, I'm still looking "
 
" I also have a 63 evinrude 75

" I also have a 63 evinrude 75 h.p. outboard. does anyone know what the ac voltage should be coming off the stator (two yellow wires)is at 2000 rpm ? mine is around 1.2 volts but that does not seem right.the ohms across the field is 2 ohms and that does seem right, its in the range of 1.7 and 3.1 ohms. my diodes, regulator, fuse, ammeter, and connections all seem to be good but i am still losing charge. i tried jumping the regulator like the shop book said to do and it made know difference.do i really need a new stator. any ideas ? "
 
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