joecb wrote:

If I understood correctly, you said that you had spun over the motor without having the SP wires either grounded or connected to grounded spark Plugs. If true, you may have compromised insulation somewhere in the secondary circuit. That high voltage will find a path to ground, either internal to the coil or perhaps burn through the SP wire insulation, like at a sharp bend or clamp.  I suppose that you could be seeing a “leak” somewhere in the secondary, somewhere between the coil and the spark plug boot,,, maybe ??? If there is a weak spot in the insulation, it would not be detectable with your ohm meter.

Joe B

So it’s possible I fried my coils, even if I rechecked them after I pulled the mag plate off? Sounds like I could have done “hidden” damage that I can’t recover from?

Dang it!

I knew I remembered someone, Crosbyman I think, saying something about not spinning the motor unless something electrical was done. I just couldn’t remember what.

Tell me if this makes sense. Could the high voltage that was arcing across #2 from the solder to the laminate be the “leaking high voltage”? If so, was I theoretically still safe then? If so, did I ruin it when I got the arc to go away with the electrical tape?

Is it possible these coils were toast b4 I got them and that is what was causing my original complaint? I say this because I’m 99% sure these are the same coils that were in the original motor when I got it last year. (LOL, playing the blame game)

I have spare coils, but trying not to use them.

Thanks for the comments. I appreciate your time.

Best Regards

Hope you feel better soon.

Thanks,

frankr wrote:

OK, here goes…..

FACT.  Electricity follows the path of least resistance.

Fact: when time to fire, the voltage in the coil secondary starts at zero and rapidly rises until it is finds a lowest-resistance path to ground   Then it arcs to ground via that path and the energy dissipates and it starts all over again till next time.  Hopefully, that path of lowest resistance is through the plug wires to and across the plug gaps.

Fact:  Those old mags were capable of producing possibly 50 K-volts.

Fact:  The path thru the plug gaps might require only 30 K-volts to fire, or whatever, according to gap width, temperature, compression pressure, etc.  So, it actually only needs 30 K-volts (or whatever) to run.

Fact: We are so programmed in our heads to look for that magical “fat blue spark”, so if it will produce that magical fat blue spark we assume everything is ok.

Fact:  For whatever reason, Johnson decided to limit the coil output to something a bit over the actual voltage needed to run   I suppose to protect the coils from over-volage,   When built, those mags had L-shaped “teaser” brackets near the soldered connection.  If the voltage is to high, the spark jumps to the teaser bracket and is dissipated.  OR, if somebody has removed the teaser brackets, it looks for the next-lowest path of resistance, likely to the coil mounting screw.

Which brings us to the conclusion:  If it is arcing to the screw, the voltage is way beyond what is necessary to fire the plug.  The mag is ok, in fact better than it has to be, and is not broken, and doesn’t need fixing.

 

 

 

 

 

 

Frank,

Thank you. Lots of good information. I don’t remember the name, but Johnson had a name for the ‘teaser’ didn’t they? I think it was called the Maverick system?

I understood everything you said and it all makes sense, sort of.

To clarify, you are saying that it is okay that I could not achieve greater than 1/8″ spark gap in the spark tester?

The even bigger question is that while testing via the spark tester, when a I open the gap more than 1/8″ is when the coil  shoots the voltage to the laminates. Your saying that won’t/shouldn’t happen under true running conditions?

I realize that the plug gap of .030, ~1/32″ is much smaller than 1/8″ and should fire before the solder joint to laminate BUT it is admittedly hard to ignore the repeated edict that ‘solid blue spark at least 1/4″ is necessary”.

In your opinion the mag plate, as built (pulled it off the motor and built brand new one) previously would likely be enough to run the motor?

I appreciate the wealth of information. I really liked your approach (LOL), “FACT”. Kinda makes one pay full attention to the words on the page.

Please let me know what you think?

Try and get better. It sucks to be sick when trying to work. I appreciate you taking the time today, even sick, to help out.

Best Regards,