1965 6 hp Evinrude erratic spark

Bullie

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I have been working on a 1965 Evinrude 6 hp 6502 I picked up recently. Had no spark when I brought it home. I polished the points and got spark but the top cylinder started firing quite a bit earlier than the bottom (using my drill to check spark) but would eventually start firing. I put it in the tank and it wouldn't start with the rope, I had to spin it faster with the drill to get it to start. It wouldn't stay running in gear so I did a spark check. Pulled the top and it stopped running. Pulled the bottom, no change. So, I have been back over everything I can think of. I put a new set of condensers in it. Coils look good. I cleaned all the grounds, pulled the plate and checked the wires. The top wire (this is the one that was firing perfectly) had a couple of small cracks in it right at the clamp under the plate but the other looked fine. I put everything back together, checked spark again and lower cylinder still started firing slower and seemed to miss a spark every few revolutions. What should I check? Why would it miss fire like that?
 
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kbait

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You may be losing connection between coil and spark plug. I'd first separate the wire from the plug boot, cut off 1/4" of the wire, re-attach the spring-clip, and re-insert into rubber boot. Then test spark again. If still weak/intermittent, redo wire/coil connection (need to remove armature plate and coil), and also inspect bottom of coil for cracks or pinhole burn marks. If still poor spark, report back..
 

kbait

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Oh, also be sure the armature plate has no lateral play, and widest point gap is .020" for each pointset.
Good luck!
 

wrench 3

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If your going to pull the plate again I'd replace the wires. The one is showing signs of wear anyway and I've seen them before that looked fine, tested OK, but when everything else checked out OK, replacing them solved the problem.
 

ondarvr

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What does a good coil look like?

Swap them and see if the problem follows the coil.
 

Tim Frank

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You may be losing connection between coil and spark plug. I'd first separate the wire from the plug boot, cut off 1/4" of the wire, re-attach the spring-clip, and re-insert into rubber boot. Then test spark again. If still weak/intermittent, redo wire/coil connection (need to remove armature plate and coil), and also inspect bottom of coil for cracks or pinhole burn marks. If still poor spark, report back..

+1^^

Also, how on earth are you determining that
the top cylinder started firing quite a bit earlier than the bottom
?
First of all, it is meant to do that, 180 degrees earlier.
Second, if the coils "look good', maybe the motor "looks like it will run OK" and you are good. :)
Check the coils properly with an ohm meter.
 

Bullie

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+1^^

"Also, how on earth are you determining that ?
First of all, it is meant to do that, 180 degrees earlier."

It's kinda neat Tim. If you use a drill you can slowly increase the revolutions and try to figure out what is happening with the spark. And, by quite a bit earlier, I meant the top cylinder fires at a lower rev speed. The lower cylinder did not fire half a revolution after the top (180 degrees) it took considerably higher revs before the bottom would fire at all. Maybe I wasn't clear enough.


"Second, if the coils "look good', maybe the motor "looks like it will run OK" and you are good. :)"

What I mean by "looks good" is that the coils are not the 60s coils that tended to crack, so I assumed they had already been replaced at some time. There is no obvious damage or burnt spots where they might be arcing. All the wires look good...nothing is glaringly out of place with them.

And, this motor is quite ugly. At some point a PO decided to rattle can the poor thing a bright leaf green color. And, by bright leaf green I mean really green, like you might see in the spring time on an oak tree maybe. I don't know where you are or I would be more specific about when spring should occur in your area.

"Check the coils properly with an ohm meter."

Good Idea. And, by good idea I mean that this is useful.
 

Bullie

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You may be losing connection between coil and spark plug. I'd first separate the wire from the plug boot, cut off 1/4" of the wire, re-attach the spring-clip, and re-insert into rubber boot. Then test spark again. If still weak/intermittent, redo wire/coil connection (need to remove armature plate and coil), and also inspect bottom of coil for cracks or pinhole burn marks. If still poor spark, report back..

Thanks kbait. I followed up with all of this. Maybe it got a little better but I still am not getting consistent spark. The wires look to be original and have some obvious cracks under the plate just after the clamp where most of the flexing occurs. Gonna replace those when I check the coils.
 

Bullie

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What does a good coil look like?

Swap them and see if the problem follows the coil.

Maybe it will be easier to explain what a bad coil looks like.


These are bad coils from of motor of the same vintage.

There was nothing obviously wrong with the coils on this motor. No cracks, holes, etc that I could see. Nothing that would make me think, "Oh, yeah, that is the problem."

I will try swapping them out.
 

ondarvr

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There is no "look" for a bad coil, it could appear to be brand new, it just doesn't work correctly. You need to test or swap them to see if a coil is good or bad.
 

oldboat1

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If you haven't already, I would reset the spring clips on the plug ends of the wires, and the connections at the coil spikes. Should be solid core wire. Would check condition of magnets, and assembly of coils (flush-mounted.) Points are the usual source of problems -- clean and regap. Finally, I would spray all connections with electrical cleaner. Need to use a spark tester, solidly grounded -- 1/4" spark.
 

58rude

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Thanks kbait. I followed up with all of this. Maybe it got a little better but I still am not getting consistent spark. The wires look to be original and have some obvious cracks under the plate just after the clamp where most of the flexing occurs. Gonna replace those when I check the coils.
Your cracked wires are probably shorting to ground under the plate. I would replace the cracked wires first.
 

Bullie

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Wish I could get wire today. I have the day off tomorrow so I hope I can find what I need at the local small engine shop or Napa. I did cut off both ends of the wires and reconnected them. After seeing the cracks open when I twisted the wire I felt like I might be wasting my time. But, this is how you learn.

I will have to look up the procedure to test the coils. I have done this once in the past but it has been a while. Need a refresher.
 

Bullie

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Another question on this motor. It has the "old style" fuel pump and thought it is pumping there is a leak when I pump the primer bulb at the screw in the center. It doesn't leak any other time. Will the newer square pump replace that one?
 

oldboat1

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think the cover gasket and screen are available for the original, not sure about the diaphragm (cover gasket may be the fix needed, though).

Otherwise the square pump is maybe $80-$100 -- or maybe a used one off Ebay, and a rebuild kit. Need the attaching gasket as well (not sure whether all kits include them).
 

Bullie

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I have several of the little square ones around if I cannot repair the other. I actually would like to repair it if possible though. It may be just the little plastic washer on the center screw as that is where it is leaking.

For some reason Racerone, I had in my head that parts weren't going to be available for that style pump. Maybe I read that on leeroys page. Anyway, I see that there are some parts available for it. I don't see a kit though. Is there one available that I have not seen or do I order separate parts?
 

Bullie

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Success! I picked up some new wire this morning. Bought the last 4 feet of copper core 7mm wire NAPA had after I bought 10 feet of wire that didn't have a metal core. They didn't want the wrong wire back. LOL Anyway, even though the old wire showed continuity it was still bad, just like I was advised. Hopefully that's the last of the electrical bugs.

The coils ohmed out fine.
 
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