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85 Evinrude 90 -- spark issue

S

Sam110

Regular Contributor
Serviced my boat early May ran the motor '85 Evinrude E90TLCOS and cleaned things up after winters storage. Motor fired up and ran good. All was good for my first outing. Finally had the opportunity and pleasant conditions to put the boat in the water. At the ramp the motor wouldn't start. Cranked strong, primer pump was delivering fuel, but never even sputtered. Pulled it out and came home.

At home I pulled the plugs and they were wet. (new last fall) Using a spark tester I had made in prior years no spark was seen jumping the 7/16" gap on any of the 4 high tension leads. So, I doubt it would be all 4 of the coils at once and unlikely that both power packs went out at the same time in a 3 month span so I'm in the fog as to where I should look next? Could it be the rectifier / regulator? I've gone over the wiring looking for any evidence a rodent may have chewed something but didn't find any such evidence and all connections seemed secure.

In the fall of 2018, I had conducted a spark and compression test. Spark was strong in all 4 high tension leads. Compression on the cold engine was 110 / 109 / 108 / 108. Fuel tank was full over the winter and there is a water separator in the system.

Any suggestions as to where I should look next would be appreciated.
 
The " neutral safety switch " prevents cranking if control box is in gear.------It has nothing to do with preventing spark.----The OP says the motor is cranking just " fine ".
 
Remove the black/yellow wire from the ignition switch. Make sure that the same wire IS NOT still attached to the Dead-Mans kill switch. If you now have spark... either the ignition switch or the kill switch is faulty. You'll need to determine which.

If still no spark, remove that same black/yellow wire from either powerpack. If that stated powerpack now has spark... the black/yellow wire would have a conductive type short somewhere along its length between the powerpack and the ignition switch and will require replacing.

Let us know what you find.
 
Got to things rather late this evening but I disconnected the ground from the battery and pulled and opened up the control box to see if I could identify anything amiss there. (In the past I replaced the overheat horn which had been bypassed by the former owner and thought perhaps it could be something there came loose) All appeared "OK" to me. I pulled the black/yellow wire from the Ignition switch and from the 'kill' switch as Joe suggests in step 1 of his diagnostic test. I did not test crank for spark as I wasn't sure about the control box ground wires being disconnected. Wasn't sure if I would cause damage without a ground. The pic's I've included show these two grounds; in another pic I bolted them together and clipped a grounding jumper wire which I can clip to a known ground under the dash. Is this grounding even necessary? The control box itself doesn't seem to be grounded. I want to avoid putting the control box back together for this test, but I don't want to put the power to the switch until I'm relatively sure I'm not going to cause some "magic smoke" to appear or blow a fuse somewhere.

I tested the emergency Kill switch with my ohm meter and it seems to be functioning correctly. I have not tested the battery under load nor am I sure how to do that test or what voltage I would be looking for? Can I simply crank the motor with a meter connected to the battery and see what voltage drops to?

OK, maybe tomorrow the site will allow me to upload the pic's. Nothing doing tonight, just spins and spins.
 
Ok, had to resize the pic's in order to post.

So is it 'safe' to crank with the switch out of the control box and no ground or should I use the jumper as in the pic to a known ground before I attempt to crank the motor?
 

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Joe, as per your step 1, with black / yellow wire disconnected from the switch and kill switch with ground wire connected together as it would be with the box reassembled (not with jumper as pictured) .. I have no power .. it will not crank period as if no battery at all. Battery voltage checked with my multi meter is showing 13.35 volts and was connected to the battery to see what it dropped to under load of the crank.

Before attempting to crank I checked the conductivity of the black / yellow wire from the switch connection back to the plug atop each power pack and both showed the wire was good.
 
DISREGARD THE ABOVE RESULTS FOR STEP 1
The control box being opened up I overlooked the Neutral Safety Switch. The plunger of the switch was out shorting out the test.

Shorted across both leads of the neutral safety switch and retried Step 1 of Joe's test and motor cranked with good spark. (Racer I had my multi meter connected to the battery when doing so and current didn't drop below 12v) Connected the black /yellow wires back to the ignition switch w/o neutral safety switch or Em Kill switch and motor cranked with good spark.

Since both the Neutral Safety Switch and the EM Kill Switch both test out good with positive conductivity in their respective operating positions, I'm guessing initially when my issue started, the Neutral Safety switch was somewhat in an 'activated' position. Although I did initially attempt to 'rock' the throttle handle before trying to start the motor it must have been activated. Apparently the motor cranks when the neutral safety switch is activated it just cuts out ignition power. When I tested it for conductivity in my hand it didn't take much movement of the plunger to make positive contact.

I will reassemble the Control Box with all switches and retry and report back. Thanks all.
 
The neutral safety switch, when engaged, simply eliminates voltage being applied to the small 3/8" nut terminal of the starter solenoid which would normally engage the solenoid.... this makes it impossible for thre solenoid to engage to apply voltage to the electric starter.

The neutral safety switch has nothing to do with the ignition.

Your first pots stated you had no spark. I gave you instructions how to test the ignition switch. You did and now have spark... and have spark with the black/yellow wire back on its original "M" terminal

And there you lost me. Apparently you no longer have the problem?
 
joereeves said:
The neutral safety switch, when engaged, simply eliminates voltage being applied to the small 3/8" nut terminal of the starter solenoid which would normally engage the solenoid.... this makes it impossible for thre solenoid to engage to apply voltage to the electric starter.

Explains results I got in #9 post. Because when I jumpered the two terminals of the Neutral Safety Switch together (as would be in a normal start position) and followed your step 1, motor cranked and had spark. So I then reconnected the black / yellow wires back on the ignition switch and again had crank and good spark. So I surmised the neutral safety switch was the issue all along.. (just a guess) .. then again the EM Kill switch was removed entirely from the equation .. ?? The problem now appears to be gone so it was the EM Kill switch as your step 1 test suggests ?
Click to expand...
 
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