Old 40 hp Evinrude with a "slight" miss throughout the RPM range

[Grandpa Mike]

I'm gonna take a wild stab at it and say I think we found the problem. And if this isn't bad enough, my son told me that when he removed the first coil,...the plug wire stayed where it was. Apparently no longer attached to the coil but sort-of laying against it.

I really cant believe this 53 year-old 'Rude even started.

 

[gm280]

Re: Old 40 hp Evinrude with a "slight" miss throughout the RPM range

I'm gonna take a wild stab at it and say I think we found the problem. And if this isn't bad enough, my son told me that when he removed the first coil,...the plug wire stayed where it was. Apparently no longer attached to the coil but sort-of laying against it.

I really cant believe this 53 year-old 'Rude even started.

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It does look like you have found that problem and hope that is it too. Those old engines have run for years and things like that can and should be expected. I lucked out with my old 1976 Johnson not having the coils like that bad, at least not yet. I bought all new points, condensers, and spark plug coils for that same reason. But the exciter coils look and measure pretty good for now. Hope that does fix your problem and gives you years more of trouble free fun...

 

[HighTrim]

Re: Old 40 hp Evinrude with a "slight" miss throughout the RPM range

Yup very common sight on that vintage motor. The plug wires almost always crack off and stay when you pull the coil off.

They will sometimes start, even run for a bit. But always end up failing eventually. That plastic experimental potting.

Update with new coils/plug wires and she should purrr like a kitten.