How to check alternator on '87 Evinrude 90

[onebohemian]

I've got an '87 Evinrude V4 90 horse (E90TLCUR). I assume it has an alternator that provides current to the starting battery when its running just like in a car. I've got a manual but it's not helping me figure out how I can check how much juice is coming off the motor to the battery. I've got an in-dash voltage meter but it always reads about 12. This seems low to me and every now and then I find that I need to charge the starting battery with a portable charger as she doesn't seem to be getting enough charge from the motor. Battery is new and connections are all clean. I'd like to check the current coming off the motor while running instead of relying on the in-dash meter. <br /><br />Assuming I have a multi-meter, where do I want to connect its leads and what output from the motor should I see?<br /><br />Thanks in advance, <br /><br />Mark<br />Minneapolis

 

[Dhadley]

Re: How to check alternator on '87 Evinrude 90

Does your tach work?

 

[Hooty]

Re: How to check alternator on '87 Evinrude 90

...or, you can check the voltage at the battery with the engine not running, then start the engine and check the voltage again. If the voltage goes up with the engine running, the charge system is working. If it doesn't increase, you've got a problem somewhere. You can do this on the hose but don't exceed 2,000rpm. <br /><br />c/6<br />Hooty

 

[rickdb1boat]

Re: How to check alternator on '87 Evinrude 90

Sounds like a rectifier gone south to me...

 

[onebohemian]

Re: How to check alternator on '87 Evinrude 90

Thanks for the input.<br /><br />I combed through my seloc manual again last night. Although I think I understand better now how the charging system works, it's still far from clear in my mind. Haven't poked around the motor yet to really understand where every part is (i.e., rectifier, etc.), but I think I now understand that the alternator isn't a one-piece, self-contained unit like on a car and that there are a number of probable causes for the problem I'm having. <br /><br />Tach appears to work fine.<br /><br />My next step is to do the simple measurement of the charge at the battery terminals with motor not running and then with it running to see if I get in increase. From everything I've read, even if I get an increase, it's possible that it won't be enough and could still indicate a rectifier problem. If I have to check the rectifier, I'll be posting more questions here. Because the rectifier is original (from 1987), I'm wondering whether it just makes sense to replace it. Any ideas what a rectifer goes for these days?<br /><br />Thanks again for everyone's thoughts. I'll be back when I know more.<br /><br />Mark<br />Minneapolis

 

[onebohemian]

Re: How to check alternator on '87 Evinrude 90

Two questions:<br /><br />I have an '87 Evinrude 90hp, E90TLCUR, V4:<br /><br />1.) Where's the best (cheapest) place to buy a new replacement combo 35 amp rectifier/regulator (OEM part number 583076)? Best price I've found online is 199.00.<br /><br />2.) Although I have a Seloc manual, it does a poor job of explaining how to replace the rectifier (e.g., does the flywheel have to be pulled?). Doesn't show a schematic with each part of the electrics very well either. Went to boaterssupply.com to download the schematic but that site doesn't appear to be active any longer. Any ideas where I can get schematics online? (Otherwise I guess I'm going to have to order an OEM service manual.)<br /><br />Thanks in advance, <br /><br />Mark<br />Minneapolis<br />mprivratsky@lindquist.com

 

[james roach]

Re: How to check alternator on '87 Evinrude 90

If your tach works your charging system works.<br />If you still aren't convinced, put a volt meter on the battery while it is running. You will probably get a reading around 14 volts.

 

[kgw]

Re: How to check alternator on '87 Evinrude 90

Hi Mark,<br /> If your tach works your stator (alternator) is working , voltage regulator (rectifier} can still be bad.what others have told you about voltage at the battery will tell you what the whole system is doing.

 

[Solittle]

Re: How to check alternator on '87 Evinrude 90

If you plan on doing your own work on that motor you will eventually might want to get a manual which tells you and shows you what you need. OMC manuals are the only way to go. Among the places you can find them is here:<br /><br /> http://www.theoutboardwizard.bizhosting.com/parts_service_and_owners_manuals.html

 

[onebohemian]

Re: How to check alternator on '87 Evinrude 90

Final update on this situation.<br /><br />Turned out the rectifier/regulator was bad. Not allowing enough juice to battery. As with everything else I've had to purchase for this boat, the part was the most expensive one of its kind. At least my starting battery will start the boat from now on after a long day of fishing. Can't wait for opener, although I may try to do some panfishing this weekend just to get the boat in the water.<br /><br />Thanks for everyone's help.<br /><br />Mark<br />Minneapolis, MN