1964 Evinrude 75hp, testing generator

[Evinrude Boater]

My engine didn't have a generator belt when I bought it and I don't know if the generator even works. Is there a way to test it before buying a belt for it? It would save me running the battery to shore every week for a charge.

 

[Chris1956]

Re: 1964 Evinrude 75hp, testing generator

You may test the generator the same way you test a starter. Disassemble and test the armature for continuity across the windings, but not to the core. Test the field windings for the same. Inspect the brushes and commutator for burning and cleanliness.

Do you also have the external voltage regulator? It is essential, and may be the hardest part to get. if you get desperate, you might find one in JC Whitney for an old sixties automobile.

 

[Evinrude Boater]

Re: 1964 Evinrude 75hp, testing generator

Hmmm, sounds like something for a professional or at least someone who knows something about electrical motors. My starter is starting to sound noisey and I would like to take it apart to check the bushings. It sounds like the bushings are dry and are vibrating when it cranks.
I'm not sure if the voltage regulator is present. There is a metal box on the cover of the junction box. It has a black metal cover and about 5 terminals along one side with a few wires connected. Could that be it?

 

[Molaker]

Re: 1964 Evinrude 75hp, testing generator

A good automotive electrical shop should be able to test and/or repair both the starter and generator. If you have such a shop nearby, just pull both off and take 'em there. There cost shouldn't be extreme it the units are not toast.

There is a metal box on the cover of the junction box. It has a black metal cover and about 5 terminals along one side with a few wires connected.

That sounds like the regulator. There should be a terminal labeled "A" or "Arm", one labeled "B" or "Batt" and one labeled "F" or "Field". As for the two other terminals, I haven't a clue.

 

[Chris1956]

Re: 1964 Evinrude 75hp, testing generator

That motor may have a reduction type starter. It will then have gears which need grease, in addition to the bushings. Usually they do not have ball or roller bearings.

 

[F_R]

Re: 1964 Evinrude 75hp, testing generator

There is a very simple test for the generator. You need a couple of jumper wires with alligator clips on each end.
1. Remove the belt.
2. Just to be safe, I prefer to disconnect the wires from the generator.
3. The battery negative cable must be hooked up.
4. Clip a jumper wire to the generator Field terminal stud. That is the smaller one. Clip the other end to a good ground on the powerhead.
5. Clip another jumper to the battery positive terminal. Clip the other end to the generator Armature terminal. That is the larger one. The generator should run slowly like a motor. If it does, the generator is working. Run it just long enough for a test. It is not good to run it long and overheat it.

This only determines whether it is working NOW. It says nothing about the condition of the brushes etc.

Make sure you identify the larger and smaller terminals correctly. If you hook it up backwards it will polarize the generator backwards. Let's not get into that just now.

The black thing in the junction box cover is the regulator. Be glad you got it, they are expensive.

 

[Evinrude Boater]

Re: 1964 Evinrude 75hp, testing generator

Thanks for the information. That should give me something to do while I'm on vacation.
I did read about polarizing the generator prior to use. I didn't understand the purpose of the exercise but it's explained in the manual as being VERY important.

 

[MANDINGO_1981]

Re: 1964 Evinrude 75hp, testing generator

i tested tested the generator as you described. The generator does run like a motor, however it still won't charge. How do I no if the brushes are bad?
I also checked all of the fuse and wiring. Also I jumped the generator field stud to bypass the regulator and still won't charge. Any advice....?Carl

 

[F_R]

Re: 1964 Evinrude 75hp, testing generator

i tested tested the generator as you described. The generator does run like a motor, however it still won't charge. How do I no if the brushes are bad?
I also checked all of the fuse and wiring. Also I jumped the generator field stud to bypass the regulator and still won't charge. Any advice....?Carl

OK, by "jumped the field stud", you mean that you grounded it? That should make it charge. You just got done checking the brushes when you motored it. That at least proves that they are in working condition. Of course they could be nearly worn out but as of right now they are working. You did mention that it is noisy. That is the ball bearings, but in itself won't keep it from working unless the armature is dragging on the fields. But they do need to be replaced.

If you have no charge by grounding the field, either your regulator is no good, OR the wiring is bad between there and the battery. OR some clown has put a car regulator in there. OR you aren't running it fast enough. It won't charge till you get it up to about 2000 RPM. You need to have it in gear, on a boat, in the water before doing that in order to prevent runaway or possible damage. Note that because of the belt pulley sizes, the generator runs much faster than the flywheel. So at 5000 engine RPM the generator RPM is really whizzing. That is why you have to replace those noisy bearings before they sieze on you.

 

[MANDINGO_1981]

Re: 1964 Evinrude 75hp, testing generator

If the regulator is bad would that pervent the generator from charging? Also It is the original prestolite regulator. Carl