'73 Evinrude 115 - No spark when wet??

[BOAH]

I have a 1973 Evinrude 115 that has had an intermittent no spark issue since I've owned it for the last five years. Sometimes for the first start, she can be a little grumpy and take a bit of coaxing to start but after she's been started, she runs great for the rest of the day.

Today I went to start it in the driveway and I'm not getting a spark. Last night it rained and there's a little bit of water in a spot or two in the lower motor cover. Maybe because the cowling doesn't completely seal? Not sure.

Anyway last time I got a no spark, it was the same type of situation. It had rained the night before and everything inside of the motor had condensation on it. I let it sit out in the sun for a while and after an hour or so, it fired right up.

So my question is that if it is a condensation problem that might be causing my no spark, where do I begin and what can I do about it?

As always, thanks for your help!

 

[Joe Reeves]

Re: '73 Evinrude 115 - No spark when wet??

First..... When this "No Spark" problem raises its ugly head, (Key In The ON Position), remove the black/yellow wire from the powerpack. If you have spark with that wire removed BUT no spark with it connected, the usual cause is a shorted ignition switch.

Test the ignition switch by having the black/yellow wire connected to the powerpack where it belongs, (Key Still In ON Position), then removing that black/yellow wire from the ignition switch. If you have spark when that wire is disconnected from the switch BUT no spark with it connected, replace the ignition switch.

EDIT of 08/12/12.... Disregard mention of having the key in the ON position. I meant to say "In The START Position" as the engine must be cranking in order to check the spark.

Second.... Inspect the stator as follows.

Look under the flywheel at the stator which is the beginning of the battery charging and ignition system.

It is no doubt a sealed unit BUT there will be a series of small coils on both sides of the stator that pertain only to the battery charging system. You are not interested in these at the moment.

On that model, at the extreme front forward portion of the stator, and at the extreme rear portion of the stator, there is a larger black coil (2 coils in all) which provides approximately 300 AC volts to the powerpack via two wires (Brown & Brown/Yellow) in order to engage the ignition. These are the two areas of the stator you are interested in. Should either of these two areas crack and be leaking a sticky looking substance out of either coil, that results in a voltage drop to the powerpack which in turn results in weak, erratic, and eventually no ignition (spark).

You may need to remove the flywheel in order to inspect the stator properly. If so, when reinstalling the flywheel, make sure to torque the flywheel nut to 105 foot pounds, otherwise the flywheel key will surely shear and throw the engine out of time.

 

[BOAH]

Re: '73 Evinrude 115 - No spark when wet??

Thanks, Joe

Yep, sure enough, I went out to test it and I've got spark again... I'm happy about that but at the same time, sure would be nice to track this thing down.

I'm going to print out your instructions and keep them in the boat so I'm ready when it happens again. For clarification, when you said that to test this, you want the key "ON". Does that mean the key is in the "Run" position or the "Start" (cranking) position?

Thanks again

 

[Joe Reeves]

Re: '73 Evinrude 115 - No spark when wet??

For clarification, when you said that to test this, you want the key "ON". Does that mean the key is in the "Run" position or the "Start" (cranking) position?Thanks again

That would be the "RUN" position. You do not want the engine to be cranking.

EDIT of 08/12/12.... Disregard the mention of having the key in the RUN position. I should have stated to have the key in the START position as the engine must be cranking in order to check the spark.

 

[BOAH]

Re: '73 Evinrude 115 - No spark when wet??

I'm sorry for being so thick about this but the more i think about this, the more that I don't understand. How do you check for spark if you're not trying to start the engine?? I have a spark tester to check the gap of the spark but the only time I can see a spark is if I'm cranking the motor.

You said

"..(Key In The ON Position), remove the black/yellow wire from the powerpack. If you have spark with that wire removed..."

What in the world am I missing?

 

[Joe Reeves]

Re: '73 Evinrude 115 - No spark when wet??

I'm sorry for being so thick about this but the more i think about this, the more that I don't understand. How do you check for spark if you're not trying to start the engine?? I have a spark tester to check the gap of the spark but the only time I can see a spark is if I'm cranking the motor.

You said

"..(Key In The ON Position), remove the black/yellow wire from the powerpack. If you have spark with that wire removed..."

What in the world am I missing?

My apologies..... I was thinking about another member's similar problem when I answered your question about "cranking" the engine over. His problem involved a test to see if voltage was being applied to that black/yellow wire when the key was simply in the ON (RUN) position. Please ignore my previous reply.

In your case, of course the engine must be in the START position, cranking over to check the spark. Sorry to add to the confusion.

 

[BOAH]

Re: '73 Evinrude 115 - No spark when wet??

So here's the latest. I go to check the spark today and I can't see a spark in my tester. I had the tester set at 3/8". So I pulled the cover off of the power pack to check and see if I can isolate the no-spark per your suggestion about the black/yellow wire.

Just to make sure to double-check the spark, I pulled the sparkplug and grounded it just to check and see if maybe it was a weak spark that wasn't jumping the gap on the tester. Sure enough, I can see a spark when grounding the plug. So I put the tester back on and sure enough, I see a spark. I then set the tester at 1/4" and it looks like a good spark there as well.

This thing is driving me insane. If it's broke, it would be great if it stays broke so I can try to fix it! Anyway, I'm about ready to just go ahead and get a new stator. I haven't pulled the flywheel yet but all of the wires look prehistoric so it wouldn't surprise me if it's in the condition you described above.

I can also see that one of the wires from from the rectifier is in bad shape so I might as well replace that at the same time.

I've spent some money on this so far and all of these parts aren't cheap. Any chance that there's a problem with the power pack as well? I'd prefer to have to not buy a new power pack too. ouch...

And by the way, I did replace the ignition switch a year ago. I guess it could be bad but it is fairly new.

What do you think?

 

[BOAH]

Re: '73 Evinrude 115 - No spark when wet??

bump...

 

[Joe Reeves]

Re: '73 Evinrude 115 - No spark when wet??

It is acting like a failing stator.... However have you inspected that stator as I mention in my first reply above (#2 post) to see if it might be showing signs of failure (meltdown).

 

[BOAH]

Re: '73 Evinrude 115 - No spark when wet??

I haven't pulled the flywheel yet but all of the wires look prehistoric so it wouldn't surprise me if it's in the condition you described above. Even if it doesn't look 'bad' I'm probably going to replace it anyway. My question is do you think there's a possible problem with the power pack as well?

Thanks again.

 

[Joe Reeves]

Re: '73 Evinrude 115 - No spark when wet??

Anything is possible when it comes to intermitent problems BUT I have never heard of a Magneto Capacitance Discharge type powerpack (yours) acting like that.