evinrude charging system modification

[mrfixitman40]

i have read some previous posts but not sure how they went about the modification i have a 1964 evinrude 75 hp electric shift that doesn't seem to be charging well only about 12.9 volts and my amp gauge fluctuates significantly when going from idle no wake to throttleing it up to half was wondering if the solid state modification could help this or is there something else that should be fixed if at all possible a wiring diagram that can show the modification would be greatly appreciative either way . I would like to get rid of the wiring mess that is in the boat for the rectifier board if at all possible thank you

 

[yorab]

Re: evinrude charging system modification

I have a 63 75 hp and I always wanted to get rid of the messy electrical shenanigans if there were a modification. I'll be interested to hear some feedback.

 

[F_R]

Re: evinrude charging system modification

The DC generator won't charge at below approximately 2000 RPM. It takes that much RPM to develop the voltage. Thats why the whole world went to alternators. Regulator has nothing to do with it. However, the regulator should be set to charge at about 14.5 volts (with a fully charged battery). Depends on temperature too.

Does it charge when you rev it up above 2000?

Edit: The cut-out relay closes at 12.6-13.6 volts. That's when the generator puts out enough voltage to charge the battery. If it were to close earlier, the battery would discharge through the generator.

 

[mrfixitman40]

Re: evinrude charging system modification

the charge voltage is only about 13 volts at all rpms but the amp guage actually shows dischargeing above 2300 also from what i was told and under the assumption with electric shift it actually had an alternater but i could very well be wrong

 

[F_R]

Re: evinrude charging system modification

Disregard eveything I said earlier. 1964 was the year they went to alternators. Sorry about the confusion. I'll reconsider your questions and symptoms and get back

 

[mrfixitman40]

Re: evinrude charging system modification

thank you fr i wasn't sure but as i said i could have been wrong hope to hear soon as i am starting to think it might be something to do with the couple times it jumped out of gear now that i have found this out but i was ignorant to looking at the amp gauge when i noticed the problem but ran into a car hear at work that sort of got me thinking about such turned out it was a ground issue but they all check good for voltage drop across them

 

[F_R]

Re: evinrude charging system modification

Does it ever show a charge at all on the ammeter? That is a 20 amp alternator and should charge like crazy up to the regulator setting. Most common cause of no charge at all was the 60 amp fuse blown. The ammeter would show a discharge through the field windings in addition to the normal ignition load if there was no charging.

Of course, there are also the rectifier diodes that could be blown.

The 60A fuse doesn't look much like a fuse at all, but is a ceramic thing on the positive heat sink where the brown wires attach.

 

[mrfixitman40]

Re: evinrude charging system modification

when at low rpm it shows charging about 10 amps then discharges about roughly 3-4 amps when running

 

[F_R]

Re: evinrude charging system modification

I don't have a logical explanation. Can only guess that something is loose or something being affected by vibration.

 

[mrfixitman40]

Re: evinrude charging system modification

ok thank you for the help i am gonna start with pulling the flywheel and cleaning the contacts then proceed with the step by step of wiring

 

[F_R]

Re: evinrude charging system modification

Unless the stator is damaged or open, there is no need to pull the flywheel.

 

[iwombat]

Re: evinrude charging system modification

Chiming in as an "interested party".

Does this motor have a solid-state or mechanical regulator?

 

[mrfixitman40]

Re: evinrude charging system modification

ok fr what you would suggest as a staring point just start checking the diodes and wiring ?? i would guess it would be a mechanical but fr could probably answer that better than me i am old enough to remember early charging systems but young enough not to deal with them much and he seems like he has been playing with these alot longer than me if it has wheels i would be much better with it

 

[iwombat]

Re: evinrude charging system modification

Mechanical is my guess too. If that's the case, you've got a classic case of needing to adjust and clean the points in your mechanical regulator.

If the point gap gets too big or the springs wear out, the cycle time is too great for the relay to keep up at high rpms and you get those kinds of symptoms.

 

[F_R]

Re: evinrude charging system modification

Yes start with the diodes and wiring. Especially all the plug-in connectors.

It is a mechanical regulator. The ignition switch supplies 12V to the stator's field winding via the red wire. The other field winding (blue wire) goes to the regulator which grounds it when charging is called for. That is very similar to many car alternators.

When the field wire is grounded, the circuit is completed through the field winding, causing a magnetic field. The flywheel cuts the magnetic field and causes an AC voltage in the other stator winding (yellow wires). That AC is applied to the four diodes that rectifies it to DC and applies it through the 60A fuse to the ammeter, then back to the battery +.

The regulator monitors the battery voltage and grounds the field (blue) wire as required to maintain the proper charge voltage.

Simple, huh?

 

[F_R]

Re: evinrude charging system modification

Quick test: Remove all bulbs and disconnect anything that may be damaged by uncontrolled voltage and then ground the blue field wire at the regulator with engine running. Ammeter should show a full charge.

 

[mrfixitman40]

Re: evinrude charging system modification

thank you for the time and input is the regulator adjustable or is it fixed?

 

[F_R]

Re: evinrude charging system modification

It is adjustable, but don't monkey with it if you don't know what you are doing. Especially the springs. I gotta admit that even I am not 100% knowledeable about that particular one.

 

[iwombat]

Re: evinrude charging system modification

If you can take a picture I _might_ be able to help you out. I've monkeyed with a few dozen different types of mechanical regulators over the years.

I've even done it successfully a few times

 

[mrfixitman40]

Re: evinrude charging system modification

i will see what i acan get from the mess thats back there and try to post next week if i can figure out how