1976 Evinrude 55 HP blowing coils

[mfkadz]

To make a long story short. In one motor I blew the coil for cyl 1 2 times. I moved everything to another motor and I blew the coil in cyl 2. Motor two came to me with cyl 2 blown. Before I went on the lake to test each time the motor was running great. Took it to the lake and it ran great. I would stop and fish for a little bit and restart. Sometimes I could do that a number of times. Feel pretty good about the job and then it would be hard to start. Then I would determine that a cyl was out.

The only difference between the two was the stator. I moved everything from one to the other. Including the trigger but not the stator. Could both stators be bad?

I was under the impression that the stator was not cylinder centric. It just feeds the power to terminal 1 of the power block. And the trigger signal determines where the power block sends the juice.

I have done all the CDI checks for the powerblock and coil packs. The last coil pack blew with a new powerblock.

Help me Mr. Wizard....

Mike

 

[gm280]

Mike, how are the coils blowing? Have you checked to see if the primary side is open or shorted or the high voltage side. I ask because if the same side is the blowing every time, it can point to the issue taking them out. If it is the primary side opening, then they are being feed too much current. If it is the secondary side, you could have spark plugs or even the spark plug leads as the problem. And how hot are they getting. Heat will destroy a coil quickly...

 

[mfkadz]

Hmmm, I have not made that check. I will tonight though.

mike

 

[mfkadz]

All the coils meter good. Even those that stopped sparking. When I decided they were bad they would not light the timing light. After lighting it just fine before.

I did not get new plugs yet as they were the proper ones. I am going to pick up a pair tomorrow and see what goes on this weekend. Luckily O'Reilly.

Evinrude says L78V Surface Gap or QL77JC4 plugs. Anyone have a recommendation? I believe the QL is a resistor plug for electrical interference.

Mike

 

[mfkadz]

I installed plugs at lunch. Both cyls are firing nicely. What I am left with now is the following. It runs, it coughs and slows, picks up, coughs, picks up. Someone must have heard one run like this and fixed it.

http://vid296.photobucket.com/album...5-32CC-40FC-B5F0-A31D174D0B59_zps2eunxk3b.mp4


Mike

 

[mfkadz]

I went to swap out the power module and found the screw holding the ground and module to the motor was loose. I tightened that up and things seem to have smoothed out. I balanced the carbs and it's running fine in the bucket.

I swapped in one of the supposid bad coils so far. It's bad. And that got me thinking because I thought I blew one of the ones installed in the motor. .

I grabbed the plugs I pulled out and hit them with the ohm meter. One is almost shorted as I would expect. The other was open.

Could that plug trying to fail have taken out the other coils?

mike

 

[mfkadz]

Today, after I finished moving the mulch out of the way I hooked the motor to the muffs. I had it in a tub Friday.

It sounded like a car with a big cam. I diddled and tried the other 2 power packs. One is definitely bad. I believe the other is good. But it ran the same.

I figured out it was the top cylinder. I had not had much luck with these new coils. So I went into the box and pulled out an old coil. Old being the 3 point connection attached wire black coil. Damn if the motor didn't smooth out.

I hooked the boat to the trailer and went to the lake. It started right up, backed it off the trailer. stopped it, parked the truck, started it back up. It ran flawlessly for the couple ours I was out.

I ran it up and down the lake. Stopped to fish, motored around slowly. Basically used it as if there had never been anything wrong.

I think I will spend a little time on the low idle adjustments and such to get the idle up just a bit. Otherwise I think I can say this is fixed. Well, maybe after my next day on the lake. Just so I don't call it to soon ;-).

And thanks GM for making me think about the coils and which side. That did the trick.

I do have a question though.....

I am now running on 2 old style coils. I have 3 of the new style. They do not like my motor. As far as I know these are the replacement for the original. Anyone else having issues with the newer coil packs???

WooHoo, I made Second Class. That's what I was when I left the navy almost 30 years ago.

mike