1980 70hp Johnson coil installation

[rlowhorn]

I have been having problems with what appears to be no fire on the number 3 cylinder (bottom one). The way I found it was by just pulling off the plug wires while it was running. Both of the others cause the motor to die but not with the number 3 removed. Then I checked for an ark and found was not getting one on 3. Replaced plugs and put in new plug wires, still no ark on 3. Found out that if I let it warm up a while it will eventually start to ark on 3. This make me start to research it on this forum and it seems to be a common type of problem with many possibilities. I today cleaned all the carbs but do not believe that will fix it. I am also going to start running no ethanol to see what that does. I think it is the coil and am willing to buy one and change it out. The problem is that it seems that all of the coils are connected at a connector at which I cannot remove the wire and change only one coil. If that is true I will have to replace all of the coils and some other things, of which I do not know what they are, that I do not think are bad. Can I change only one coil and if so how. How do I get the wire out of that connector or do I cut it and just reconnect the new to the wire cut? Please help me. I want to go fishing and the walleye are starting to run here in tennesee.

 

[Joe Reeves]

Re: 1980 70hp Johnson coil installation

At that plug, there are pins and sockets that are soldered to the orange coil wires which normally require a special tool to remove and replace. You do not need to buy all three coils and if you did make that purchase, you would still need to assemble the coil wires to the pins/sockets.

However, with patience and a little ingenuity (WD40, needle nose pliers, whatever), one can do the job without the special tool(s).

To test the coil (spark plugs removed) simply run a jumper from one of the wires leading from the powerpack that does fire a coil to the non firing coil orange wire. If the coil fires when you crank the engine, then obviously the coil is okay.

Let us know what you find.

 

[rlowhorn]

Re: 1980 70hp Johnson coil installation

Thanks for the reply. I do desire to test the coil. Kind of new at this outboard terminology. The timer base is the base undernearth the top of the motor. There are wires to it but I cannot trace them back to a coil. How do i know which wire to hit? In the pictures I show a coil, the connector with orange wires from the coils and wires out to what I think is the power pak. Also a picture of the timer plate. Can you tell me what wire to connect a little simpler and thanks for your patience.

 

[Joe Reeves]

Re: 1980 70hp Johnson coil installation

Yes, the timer base is the component under the flywheel (advances/retards the spark)... however, in my haste I made a mistake when I stated "timer base"... I meant to say "powerpack". My apologies for that goof. I edited my previous reply and corrected that error.

Notice the color stripes on the orange wires leading from the powerpack to the coils. The "Orange/Blue wire is the top cylinder (#1), the plain "Orange" wire is the center cylinder (#2), and the "Orange/Green" wire is the bottom cylinder (#3).

So you could run either the top (orange/blue) or center cylinder (orange) powerpack wire to the bottom coil for a test.

 

[rlowhorn]

Re: 1980 70hp Johnson coil installation

I will check tonight. If it does shown that coil is good what should i look at next?

 

[Joe Reeves]

Re: 1980 70hp Johnson coil installation

The pins/sockets within those rubber plug connectors have a habit of being pushed back slightly which results in erratic or no spark. Check to make sure that all of them which pertain to the ignition are where they belong. Also, the wires that are soldered to those pins/sockets have been know to break off, sometimes barely touching the metal pins/sockets, sometimes not touching at all, but they would appear to be okay due to the fact that they are being gheld by friction within the rubber connector.... check them.

If everything checks out, it's possible the powerpack has failed on that #3 circuit.

 

[rlowhorn]

Re: 1980 70hp Johnson coil installation

Let me tell you what happened tonight. I did as you told me and tested the #3 coil using the #1 coil. I connected a spark tester with at least a 1/2 inch gap. Got a really good spark. I then connected the tester to each spark plug wire from the other coils just to see how good a spark I had. All were a really strong blue ark. I was feeling so good about the ark that I was going to repeat the test. This time I only got and ark from the #2 coil. The #3 and #1 coil outlet was sparkless. Does this tell me anything as to the best thing to look at next? Could it still be in the pins/sockets. Just as an add on question. It so much can go wrong in the connector, why not just take it out and connect the wires to by pass it?

 

[Joe Reeves]

Re: 1980 70hp Johnson coil installation

Have the s/plugs removed when testing for spark to obtain the highest rpm available. If the plugs were still installed, you could get erratic results.

The pins/sockets are pretty close together, be sure that you touch only the one you intend to touch when testing.

The rubber connectors aren't that bad but the pushing back of the pins/sockets does happen from time to time. If you remove them, then you have the beginning of what we in the trade call a Mickey Mouse mess which is to be avoided. It's best to keep the engines design and circuitry as intended.

 

[rlowhorn]

Re: 1980 70hp Johnson coil installation

The plugs were out when I ran the test. Could it be the power unit and if so how to I determine that before making a purchase?

 

[Joe Reeves]

Re: 1980 70hp Johnson coil installation

Very strange that you had perfect spark at one time, then no spark at all.

The stator under the flywheel, look under there closely. If there is a sticky looking substance dripping down on the timer base and powerhead area, that would result in a voltage drop to the powerpack which in turn would result in erratic, weak, and eventually no ignition.

There is a black/yellow wire leading from the powerpack to the ignition switch "M" terminal (kill circuit).

Remove it from the powerpack OR if it is easier, remove it from the "M" terminal of the ignition switch. Crank the engine and check for spark. If you have spark with that black/yellow wire disconnected BUT no spark with it connected, in all probability the ignition switch is shorted, in which case replace the switch.

Best in my opinion to determine a faulty powerpack by checking everything else first... kill circuit, ign switch, stator, timing sensor, coil(s). If everything checks out, the only remaining component in the circuit is the powerpack.

 

[rlowhorn]

Re: 1980 70hp Johnson coil installation

noticed the sticky looking substance dripping last evening. Can I clean that off? When you say ign switch you mean at the key?

 

[Joe Reeves]

Re: 1980 70hp Johnson coil installation

If that stator is dripping that sticky looking substance out of it, replace it. It's failing.

Do you have a tachometer, and if so, is it functioning properly? (Charging Circuit)

Yes, ignition switch is the same as saying key switch.

 

[rlowhorn]

Re: 1980 70hp Johnson coil installation

With black/yellow wire disconnected there was no. spark. What w ould you do now.

 

[rlowhorn]

Re: 1980 70hp Johnson coil installation

Took it to lake. Never had fire on all plugs. Did have two at times. Also took another look at stator drip. Was mistaken. What I saw was a colored looked like gasket at a join in the head. Not green but red. My mistake.