What Did I Do?!

[milmo1]

In an ongoing struggle with my 20 hp Johnson, I replaced a coil which was erratic. Then I noticed the plug wires arcing from the boots to the block. So, I fabricated some wires using parts from Napa. Removed armature plate, etc, routed wires. Have not had a shred of spark since! I have taken everything apart 5-6 times trying to find an answer, no go. I thought the stop switch may be shorting, so I disconnected the leads from the point/condensor/coil connections and from the switch connectors. I wrapped the ends in electrical tape and retried - still nothing.

There really aren't that many parts, is there something I'm overlooking? Is there a way I could test the ignition spark in a simple manner?

 

[bktheking]

Re: What Did I Do?!

Did the wires have the boots on them or did you fab them yourself, what brand wires are they?

 

[tx1961whaler]

Re: What Did I Do?!

If you used automotive spark plug wires, the ones with the carbon filaments instead of real wire, then that's the problem.

 

[14ftgrumman]

Re: What Did I Do?!

When you replaced the coils, did you make the laminate portion of the coils even with the machined bosses underneath the ends of them?

Kinda hard to explain, but there are machined bosseswhere the laminate portion of each end of the coil should be even with. If they are too far away, there is no spark, if too far over the boss, the flywheel will bind there.

You should have used solid core wires, like the ones found in farm tractor universal wire sets. Did you change out the points? are they gapped at .020?
Do you have the correct wires grounded? I think it shoul be the black wires from the coils that are grounded to one of the top hold down screws, but I may be wrong.

 

[milmo1]

Re: What Did I Do?!

If you used automotive spark plug wires, the ones with the carbon filaments instead of real wire, then that's the problem.

I was told I was getting the solid core at Napa, but to be honest, I don't know the difference looking at them. They were fabricated by me.

What really seemed odd to me was that I lost spark in both cylinders at the same time. There must be something in common.

14ft: Points are new and gapped. Condensors are new. I had the coils a bit too close, and they did snag the flywheel, so I moved them back. Ground wires are correctly attatched.

 

[Silvertip]

Re: What Did I Do?!

As you made up these wires you did not notice whether they had a metal or carbon impregnated fiber core? How on earth could you attach the spark plug terminals and not notice that? And how did you terminate the coil end and not notice that? You said the points are gapped! But are they gapped correctly -- as in on the high point of the cam lobe.

 

[bktheking]

Re: What Did I Do?!

That as well as the coil adjustment, there are only 2 common denominators here, wires and coils. Did you back to coils off too far? If they aren't set right spark will dissappear for sure.

 

[milmo1]

Re: What Did I Do?!

As you made up these wires you did not notice whether they had a metal or carbon impregnated fiber core? How on earth could you attach the spark plug terminals and not notice that? And how did you terminate the coil end and not notice that? You said the points are gapped! But are they gapped correctly -- as in on the high point of the cam lobe.

Yes, they are gapped correctly (which is what was meant by "gapped"). I had a strong blue spark before replacing the wires. I replaced the wires because the boots were very old and ragged - spark was intermit jumping out of the boots. The strands in the wires appeared the same to me as the originals did. The coil end is a probe which pierces into the wire.

I just swapped in an old wire to test, and I have spark on that wire. Very weak spark, but spark nonetheless. Perhaps the coil is a touch too far, but seems lined up with the boss. Is there a trick to perfecting the alignment?

 

[G DANE]

Re: What Did I Do?!

Did you remove the little cam for the points from the cranckshaft ? If you turned ?t upsidedown, there will be no spark. The text on cam should be upwards. Also armature plate has a little ground lead. If it isnt on, there will be no spark either. Did you put every lead back where it was ?? Could sound like you shortcircued something.

 

[underpressure]

Re: What Did I Do?!

i also had the exact same problem with a new coil and with several arguments with the boat store telling me i was crazy ,and they never have problems with those coils and its the spark plugs ,they were wrong and i was right,went to another boat store and got 2 new spark plug boots and installed them and the problem was gone and motor runs perfect thanks to the help from people on this forum

 

[14ftgrumman]

Re: What Did I Do?!

Just make sure that the laminate part of the coils is flush with the bosses on the magneto plate. Loosen slightly, wiggle them around and then very carefully, move to the correct position, anything straight set against the boss will allow you to locate them correctly. Do one side of one coil, snug down the screw, do the other,check both sides, making adjustment as needed, then tighten them down.

You can tell the difference between solid core and carbon core wires right away. Solid core has twisted strands of real wire, carbon core is not.

Some times the contact pins in the coils can miss the wire in the plug wire, kind of unusual for both, but worth a look.

You did torque the flywheel to 40 to 45 ft/lb? If not, you could shear off the flywheel key and start a whole new set of problems

Are you sure that you have the black wires that come out of the coil grounded? Black to ground and on the last set of coils I changed, the green went to the points. Just for grins, unplug the kill switch until you get this sorted out.

Please let us know of your progress. These motors are really simple, it's easy to make them more complicated than they really are.

 

[tashasdaddy]

Re: What Did I Do?!

on the plug end of the wire cut back 3/4 inches of insulation and intertwine it into the spring to make sure you get good contact. coil end. make sure the pin in the coil goes into the center of the wire.

 

[milmo1]

Re: What Did I Do?!

Thanks for all the input.
I am still at this one, just need some time.
I reconnected all leads, but I'm unsure where the armature ground is? Don't remember that lead - perhaps that is my problem.
As stated, an old wire (one that was replaced) gave a very weak spark. I have a parts motor that I am stealing the wires from - as they generated a strong spark on that old motor. I am considering just swapping the entire armature plate/wire assembly over so as to introduce as few variables as possible.
The "stop" button has been a real pain in the past. Can I just disconnect those two leads down by the carb and be done with them?

Thanks again all!

 

[14ftgrumman]

Re: What Did I Do?!

Should be a conector for each lead under the hood. Black, easy to get at. Should be right out in the open.

 

[milmo1]

Re: What Did I Do?!

The plot thickens...

Last night I had an idea - maybe not a good one - but an idea nonetheless.

I have a parts motor which is a sister to my primary motor. I have already taken the carb from it, and it has no lower unit, so it is a paper weight anyway. I checked the parts motor for spark. It had a nice, thick, long blue spark. So, I pulled the flywheel, and found a beautiful armature plate assembly under the wheel. I transferred the entire assembly to the primary motor, installed the primary motor's flywheel, then checked spark - next to no spark happened. So I installed the parts motor flywheel since there may be a difference. Now I have spark on both wires, but it is not very strong. Quite weak in fact. I just don't get it. What more is there if I tranfered the entire assembly intact?
BTW, the components on the armature plate from the parts motor looked new, clean, and beautiful.

What more is there???

 

[mikesea]

Re: What Did I Do?!

do you have a kill button,if so,disconnect and see if its the button,they do go bad

 

[jay_merrill]

Re: What Did I Do?!

Proper troubleshooting involves checking one thing at at time. Changing a bunch of parts all at once just makes it harder to figure out where the problem is.

Since the problem started after changing the spark plug wires, I would swap them to a set of stock wires/boots. TD's trick of getting a direct contact on the spring clips works very well - I do that too, because its easy to get the portion of the clip that pierces the side of the wire insulation a bit off center, thus failing to get proper contact with the wire inside of it.



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