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Spark on only one bank of cylinders

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SCFordMan

New member
Hi, resurrecting this old topic... but I have a condition on my 1973 Johnson 115: cylinders two and four have spark but one and three do not.

I wanted to test the 1 and 3 coils by swapping their leads in the powerpack with either #2 or #4 that was working.

I opened up the power pack and I put the #1 coil hot wire on the #4 spot and I put #4 in the #1 spot, tightening the small PP screws. I was surprised to see that both number one and number 4 both started sparking.

I then swapped the #3 coil with the #4 coil and both 3 and 4 started sparking. I was glad to see that both the #1 and #3 coils seems to work. But was surprised to see that #4 would work when tightened in the #1 or #4 spot on the PP.

I then put the #1 and #3 coils back to their rightful places on the PP and now neither will spark, just as it was when I started.

Does this point me to the stator as a problem?
 
I would load test the battery.----Take starter apart for inspection.----Inspect battery cables.-----If motor does not crank fast you will have " no spark " issues !
 
Ok, thanks for that. In this case, the battery is charged up and the starter and the motor turns over very, very quickly, and I am getting full blue-colored spark on cylinders 2 and 4. I'm also getting ignition on cylinders 2 and 4, it will ignite and exhaust on those two cylinders. I don't think it's a low RPM problem. Any more thought on this?
 
Spark test procedure... All spark plugs removed in order to obtain highest cranking rpm... At cranking speed, tester "air gap" should be set to 7/16". Is this your procedure?

Spark should be a strong blue lightning like flame... a real SNAP! Is it?

Switching coil leads as you did would have no bearing on the stator or timer base... that is a bearing whereas all four coils would fire. Were you testing the spark with the spark plugs, not in the system, but still installed?
 
I don't have a gap tester like that, I removed the plugs, re-attached the plug wires, and grounded the plugs to the block. I could see blue spark either at the plug gap or between the plug and the block - only for #2 and #4. Might this be a Power Pack issue?
 
That test, with no intentions of insulting your intelligence, is useless. Buy a air gap spark tester at any automotive parts store, set the gap to 7/16" and check the spark properly.... or build the following:

********************
(Spark Tester - Home Made)
(J. Reeves)

You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.

Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:

..........X1..........X2

.................X..(grd)

..........X3..........X4

This can obviously be modified to a 6 or 8 cylinder setup tester.

********************
 
While looking at my motor last night, I saw that the safety switch has the white wire attached on one side, but there is nothing connected to the other pin / tab on the opposite side. My "new" manual came in the mail last night, and it shows the other side of that switch goes to ground. Thinking I should ground that tab, but seems it's current condition would prevent start-up, right?
 
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A kill switch normally has a lanyard (cord) and either a "cap" or a "clip" that holds the button in.

Button "In" the kill circuit IS NOT grounded.... The ignition (spark) is engaged.
Button "out" (clip or cap yanked off), the kill switch circuit is grounded.... No ignition, No spark.

With only one wire leading to the kill switch... unless the kill switch is somehow self grounding.... the kill switch does absolutely nothing.

The kill switch wiring is normally a black/yellow wire from the powerpack kill circuit to one of the kill switch terminals, with the other kill switch terminal going to ground.

Do the test... plugs removed... air gap of 7/16" to jump... results?
 
And the Results are In!

Actually, it's the same results. The motor sparks a blue flame across the 7/16" gap on cylinders two and four, but no spark whatsoever on cylinders one and three. Coils one and three will spark when attached to cylinder 4's terminal on the powerpack. Likewise, coil 4 will spark when attached to cylinders one and three terminals on the powerpack.
 
SCFordMan said:
The motor sparks a blue flame across the 7/16" gap on cylinders two and four, but no spark whatsoever on cylinders one and three. Coils one and three will spark when attached to cylinder 4's terminal on the powerpack. Likewise, coil 4 will spark when attached to cylinders one and three terminals on the powerpack.
Click to expand...

Take a good close look at the stator under the flywheel... normally (On that model) you can see the forward and rear portion of it quite clearly without removing the flywheel.

A large black coil exists at the extreme forward portion of the stator and also at the extreme rear portion... visible on the early model stators and hidden on the later stators within the sealed material... These two coils provide approximately 300ac volts to the powerpack capacitor, needed to energize the powerpack. Now, knowing this........

While viewing the stator closely, if you see, at one or both of those two areas, a sticky looking substance dripping down from the stator onto the timer-base and powerhead... that would result in a voltage drop to the powerpack capacitor which in turn would result in weak, erratic, and eventually no ignition/spark. Check it!
 
Ok, I didn't see any black goo like you mentioned and I have seen videos on youtube that illustrated it, but maybe I'm looking at the wrong part. I'll try to attach pictures.


IMG_2211.JPGIMG_2212.JPGIMG_2213.JPGIMG_2214.JPG
 
Over the weekend I pulled the flywheel and was a little surprised to see that the stator was more like a solid black rubberized-type unit without any exposed wire or coils or anything like that. I'm wondering if the stator had been replaced. I can send pics if anyone would like to see.

I also removed the timing base and tested the sensors on my bench. I was able to confirm that the 1x3 sensor had no conductivity and it also showed signs of the black goo of death that was oozing out of the innerds.

I saw the new timing base was about $350, which is almost double what I paid for this motor, so was seeking alternatives. I found the sensor part only available for $24, so I ordered one of those and plan to install into my existing timing base.
 
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