First Outing of the Season! :(

[imstillatwork]

And I found a slight problem.<br /><br />My brother and I launched and took a few test runs in the mouth of the Chetco River in southern Oregon (in case anyone saw.....). The motor that I hade been working on all winter ran great! The boat drove really well, for being a old fixer upper that had sat for at least 2 years. So we headed out to the first bouy (1/2 mile or so), headed up the coast another 1/2 mile or so. We were out for about 30 mintes and headed back in. <br /><br />Right when we reached the harbor entrance, the boat died. It slowed down, then completely died. The battery was dead. Here's what I've found out since I got back:<br /><br />With battery recharged and motor at idle on muffs<br />14.3-14.6v at the battery.<br /><br />Battery only: about 12.2-12.5v<br /><br />Heres what is odd:<br />When I hook the battery up I get a small spark when the last lead is connected. If I tap the lead to the battery I can here a movement on the motor. Further testing showed that the flywheel would twitch as I taped the lead to the battery post.<br /><br />Key is off the whole time. <br /><br />What should I check for? I thought I checked the output of the alternator before the regulator, but can't remember a voltage. Should be around 14-16v at idle, right? regulated to 14.x for charging?<br /><br />What would cause the alternator to take a current and try to spin the crank with the key off? <br /><br />AND: if the output voltage is 14.x to tha battery, it should stay charged....bad battery? a bad battery explains why id drained, but not why a charged battery sparks when you hook it up. I think I have two problems at once, but the motor drawing power while off is the most important I think. <br /><br />Good thing we were at the port whenit died and not out a mile away. had fun anyways! please help!

 

[imstillatwork]

Re: First Outing of the Season!

doh! 1981 70HP evinrude

 

[jfm1]

Re: First Outing of the Season!

maybe you have a bad starter solenoid

 

[imstillatwork]

Re: First Outing of the Season!

The starter is not engaging when this happens. In fact, no voltage ever gets to the starter / solenoid in these situations. Even if the solenoid was bad or going bad, how would voltage get to it with the key off unless there was another problem somewhere?<br /><br />An alternator is basicly an electric motor. Spin it, its makes electricity, give it electricity, it will try to spin. I'm stumped on how where or why the alternator is getting power with the key off, and why power is allowed to go TO the alternator. Voltage regulator? but it seems to be putting out the proper voltage....<br /><br />any more ideas? I'll double check the starter / soleniod. Heck I'll unplug it and see what happens.

 

[mjash]

Re: First Outing of the Season!

Just thinking here...Does that boat have a magneto under the flywheel...if so it sounds like you are puting voltage back to the mag. I am guessing a shorted rectifier would do that...maybe a rectifier hooked up reversed polarity, since it isnt charging either...I may be totally off since I am new to this myself

 

[imstillatwork]

Re: First Outing of the Season!

I thought it was an alternator rather than a magneto.

 

[imstillatwork]

Re: First Outing of the Season!

or both? I really need help with this. I'll try more testing and tracing when I have time on tuesday..

 

[CATransplant]

Re: First Outing of the Season!

Almost certainly the alternator is trying to turn the flywheel. That'd drain your battery for sure. I'm not familiar with that particular setup, but there has to be some sort of rectifier or diode to convert the alternator's AC current to DC. If it's shorted, then the battery can try to run the alternator as a motor, as you described.<br /><br />Try disconnecting the alternator altogether and see if your battery will hold up. I'll bet it will.<br /><br />If so, then it's the regulator or diodes causing the problem....or....perhaps wrong wiring.

 

[imstillatwork]

Re: First Outing of the Season!

"Almost certainly the alternator is trying to turn the flywheel."<br /><br />Me too.<br /><br />Is the rectifier / regulator under the flywheel as part of the alternator or out on the engine? I can't picture it right now.. I'll check later.<br /><br />Will this motor run by rope start and NO battery? I think no, since it died when the battery died.<br /><br />Thanks for the start. I'll reply what i find.<br /><br />More suggestions welcome too!<br /><br />Kevin

 

[71whaler]

Re: First Outing of the Season!

That motor should run without the battery. The battery only supplies the juice to turn the starter. I have started a 1983 75Hp Evinrude with a rope, it can be done.

 

[imstillatwork]

Re: First Outing of the Season!

Then I've got issues with the battery sparking when connecting, and draining overnight while sitting parked, and the motor dieing when the battery died.<br /><br />"I have started a 1983 75Hp Evinrude with a rope, it can be done." - Good to know, I'll try it later for 'fun'.<br /><br />The rectifier / regulator is below the power pack, would it going bad cause some of these problems? <br /><br />thanks!

 

[Seasport]

Re: First Outing of the Season!

Battery sparking when you connect the terminal indicates that it is drawing current. Sounds like you are energising the alternator coils when you connect the battery. Current shouldn't be able to flow that way. I agree with the others, check the rectifier/regulator and double check that you have everything wired up correctly.

 

[BoatBuoy]

Re: First Outing of the Season!

From the ignition parts break-down, your engine is very similar to mine. The battery charge current is supplied by the stator assembly under the flywheel. It feeds AC voltage to the rectifier which converts it to unregulated DC. The DC lead from the rectifier attaches to the positive side of the battery at the solenoid. Since it is unregulated, you might see some voltages higher than you would expect.<br /><br />Since you are seeing voltages higher than battery voltage, I suspect your stator is OK. I would suspect the rectifier. If the diodes are bad, battery could discharge as well as energize the stator.<br /><br />With that, I just exhausted all knowledge I have of outboard electricals, gained mostly through a re-wire job and my manual. If you don't have one, I highly recommend it.

 

[imstillatwork]

Re: First Outing of the Season!

BoatBuoy - <br />awsome. Thats gives my some more definate information than repeating what I've already said! <br /><br />thanks!<br /><br /> I'll start a new topic if anything comes up after I test.<br /><br />Kevin

 

[Solittle]

Re: First Outing of the Season!

Kevin - Keep with this topic if there is more to the same problem so we can follow from beginning to end.

 

[imstillatwork]

Re: First Outing of the Season!

that makes sense.<br /><br />here is rectifier story:<br /><br />Becomes slightly but noticably warm wen the battery is hooked up.<br /><br />voltage tests with battery hooked up:<br /><br />1. From ground to yellow/grey on alternator(connects to rectifier): about 2/10s volt<br /><br />2. From ground to yellow on alternator(connects to rectifier) about 2/10s volt<br /><br />3. From ground to red on rectifier: about 12.56v<br /><br />4. From battery + to battery -: about 12.59v<br /><br />I think 1 and 2 are where the problem is (bad rectifier) <br /><br />and I know that 3 and 4 are perfectly normal, (battery may not be fully charged, so 12.5 is normal for this test.)<br /><br />Output from alternator was at least 13.5v when running.<br /><br />Does all of this confirm that it is the rectifier?

 

[BoatBuoy]

Re: First Outing of the Season!

You need to check the rectifier according to manual instructions and I'm not sure what that is for your rectifier. Normally, you check ohms in one direction, then reverse VOM leads and check in the other direction, with all rectifier leads disconnected from engine.

 

[Seasport]

Re: First Outing of the Season!

The fact that you get a spark when you connect your battery terminal (which you shouldn't if there is no current draw) plus the rectifier gets warm both indicate that you have current flowing from the battery through the rectifier and stator coils. This shouldn't happen. The rectifer diode(s) will prevent current flowing this way. Current can only flow the other way when the stator coils are energised. This suggests the rectifier is faulty.

 

[imstillatwork]

Re: First Outing of the Season!

This has really helped alot. I have a pretty good knowledge of diodes and ac vs dc and the theory of whats going on here, but never actually worked on a charging system enough to be sure of the troubleshooting steps. I WILL be boating this summer...I WILL catch fish... <br /><br />Thanks everyone!

 

[CATransplant]

Re: First Outing of the Season!

Try just disconnecting the retifier completely and see if the power drain goes away. You can run that motor forever with it disconnected, just like the older ones.