Intermittent spark on 1976 35 HP Evinrude

Bobby Jay

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Sep 28, 2024
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Help! My first post here for help with my outboard. A couple of weeks ago I was almost stranded out on the lake as the engine would start but would die as soon as I reduce rpms to shift into gear. Made it home ok and took it to a marine dealer who charged $165 to install a new set of plugs (ouch). I did my own test at the lake but was unable to start it. I then bought an in line spark tester and turned it over at home and was surprised that now I had spark and it started. I hit the kill button, hooked up the muffs on the bottom end and restarted it. It would run but not well as the spark would die whenever throttling back then re fire and run if I caught it in time to throttle it back up. I bought and replaced the power module ($97) which initially made no difference. However the next day I gave it another try and now it seems to run perfectly. I reinstalled the original power module and it still runs perfectly. I am considering pulling the flywheel to see if there is anything loose or obvious. Hard to fix when it is not at present broken but I will have no confidence in it until I find what has been happening. Thoughts?
 

racerone

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Dec 28, 2013
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Perhaps best to avoid that dealer.------Remove flywheel with a puller that uses 3 bolts.-----Replace condensers.----CLEAN / SET the breaker points.--------Test run.
 

Bobby Jay

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Thanks racerone. Just came back from a water test on the river. I don't think it has ever run better. I am still questioning why would it be the condensers or points as when it did act up I do not think there is any spark on either cylinder. It is as if the kill button was being pushed. I have a friend with a puller coming tomorrow. I will see what we find if we do decide to pull the flywheel.
 

racerone

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??----So you do not want to do a simple inspection or routine maintenance ?
 

jimmbo

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Well it is 48 yrs old, maybe when Armature Plate is moving the Plug Wires are Flexing and the Internal Resistance rises, or the Insulation is weak, and the Spark doesn't make it to the Plug
 

racerone

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Those were the factory replacements like 40 years ago.-----Does spark jump a gap of nearly 1/2" on a test device , yes or no ?----List actual trouble shooting steps you have done.
 

saltchuckmatt

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Jul 19, 2019
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2,652
Is this an electric start....? Tiller motor?

Anyhow, could be many things. Weird partial problem with the kill switch, or neutral locator switch on the starboard side....shorting wire.

This assumes the engine itself is mechanically fine.
 

Bobby Jay

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Sep 28, 2024
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We found a broken wire where it goes up under the flywheel. Pulled the flywheel, spliced in a short piece of wire and reassembled. It seems that everything is running as it should now. Thanks Racerone and Saltchuckmatt.
 
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jimmbo

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Neat what a bit of Troubleshooting/Inspection can reveal...
 

Bobby Jay

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Sep 28, 2024
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4
We found a broken wire where it goes up under the flywheel. Pulled the flywheel, spliced in a short piece of wire and reassembled. It seems that everything is running as it should now. Thanks Racerone and Saltchuckmatt.
Hopefully this will be my last post on this saga. I have been successfully starting this engine daily while waiting for a water jacket gasket that I noticed leaking. Until today it would not fire. I suspected a no spark condition AGAIN. Checked the resistance of the wires going under flywheel and they were within spec. Hooked up spark plug tester and was surprised that it started. I did however notice some redish powder on the tip of one coil where the spark plug wire snaps on as well as inside the spark plug wire cap. After thoroughly cleaning with contact cleaner and q-tips it started up easily. What would cause the reddish powder? Is this likely to have been one of my 2 problems all along? I sure hope so.
 

racerone

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Sounds like it was rust.----I doubt that was the issue in this case.
 
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