Electronic Ignition

[ndutton]

It will be interesting to see if I can get the motor to run with the 1.5 ohm coil again just for fun, but I doubt it.

Please keep in mind Shawn that this test may put undue amperage through your EI module.

there is more testing to do there to see if I can keep the engine running with the voltage I want in the system (14.1-14.2)

Why did you choose this particular voltage? Anything to do with the voltage loss through your isolator?

Another nice byproduct of running the engine while I do other stuff around the boat at the dock when it is cold is that the engine heats up the cabin very nicely!

Better the engine than the coil

[sastanley]

Please keep in mind Shawn that this test may put undue amperage through your EI module.

Good point.. I have a 2 ohm resistor that should be sufficient at normal voltages....maybe I should throw that coil away or stack more than one resistor in front of it.

Why did you choose this particular voltage? Anything to do with the voltage loss through your isolator?

Yes...I may have to ditch the isolator if I cannot get my voltage where I want it with fixed regulators. 14.1-14.2 charging is my target voltage under normal conditions. While it seemed like a great solution at first, the extra complexity of the adjustable regulator is beginning to wear thin. The possibility it is blowing up $35 coils left & right isn't keeping it in my good graces either.

Better the engine than the coil

[hanleyclifford]

resistor in weird place

i have discovered an A four with electronic ignition with a resistor wired between the black terminal of the ignition module and coil -. Has anyone ever heard of such a thing?

[msauntry]

FYI- You can tell if you've burned up your Pertronix module because it has a sticker on it that is temperature sensitive. It'll be melted if the unit has failed.
I believe this only applies to the original Pertronix module and not the Pertronix "II" that has supplemented or replaced it.

[ndutton]

i have discovered an A four with electronic ignition with a resistor wired between the black terminal of the ignition module and coil -. Has anyone ever heard of such a thing?

I've never seen one that way but thinking on it I don't have a problem either. It's the circuit amperage that matters and the negative side plays an equal role.

[smosher]

Thats how I have my ballast resistor wired in.

Steve

[Ball Racing]

If you have a resistor on the negative side, then you don't have to worry as much about mounting location, and about something laying against it and shorting it, as it's already on the ground side?

[ndutton]

I don't think so.

With the resistor on the ground side, a short there will cause current to flow constantly and will eventually cook the coil, EI module or both. The ground side of the ignition isn't a solid ground, it actually switches the the ignition circuit on and off. A short on that side negates the ignition function.

[ndutton]

I wanted to bump this thread and reinforce an advisement.

For those with electronic ignition who choose to follow the recommendations set forth in this and other threads aka the Rule of 2011, whenever you replace a coil I advise measuring its internal resistance and running the calculation described in the first post in this thread NO MATTER WHERE YOU BOUGHT THE COIL.

This is about taking personal responsibility for your own installation, your own engine, your own boat. Do not blindly take published specifications at face value or in other words, trust but verify. If you changed the spark plugs you'd check their gap, if you replaced the alternator you'd measure its output voltage, same goes for the coil.

Be vigilant my friends

[hanleyclifford]

I wanted to bump this thread and reinforce an advisement.

For those with electronic ignition who choose to follow the recommendations set forth in this and other threads aka the Rule of 2011, whenever you replace a coil I advise measuring its internal resistance and running the calculation described in the first post in this thread NO MATTER WHERE YOU BOUGHT THE COIL.

This is about taking personal responsibility for your own installation, your own engine, your own boat. Do not blindly take published specifications at face value or in other words, trust but verify. If you changed the spark plugs you'd check their gap, if you replaced the alternator you'd measure its output voltage, same goes for the coil.

Be vigilant my friends

Lot of Truth there--- especially the part about " adjusting as necessary" and "not taking published specifications at face value". One thing we might agree on---everyone needs a good multi meter and knowledge of how to use it.

[ndutton]

Lot of Truth there--- especially the part about "adjusting as necessary" . . . . .

Where is that part you quoted?

[hanleyclifford]

Where is that part you quoted?

Post #1 by ndutton

[ndutton]

I see, adjust the safety margin as necessary, the only factor we applied in consideration of Pertronix's MAXIMUM specification. Hasn't been necessary.

I apologize if the quote mentioned from the first post in this thread was confusing. Perhaps a paragraph, provided here in its entirety for full context, from another recent thread will help clear the haze:

For the record, even though it has been suggested occasionally, we don't make up our own target values. This trip point was the result of solid testing. The 4 amp ignition system maximum described in the Rule of 2011 was a specification from the manufacturer of MMI's electronic ignition product. I'll admit the 15% safety margin applied in the Rule of 2011 was ours but subject to change after subsequent testing if the testing lead us in that direction. It didn't.

In the same thread it was suggested our conclusions in the Rule of 2011 were reached independent of experience (post #33) which of course is untrue (we seem to go through that a lot, don't we?). The postulates were fully and successfully tested in real world applications by multiple members before conclusions were published. Anyone who takes the time to read the 5 star thread Coil Input Information knows this.

To repeat the advisement so it doesn't get lost in other superfluous chatter, be sure to measure the resistance of any new coil prior to installation regardless of its source or pedigree. For those so inclined, apply the measurement as described in the first post in this thread.