I have my old coil and my new coil and I ran some bench tests on them today.
I take my multimeter and place the red probe on the + post, and the - probe on the - post.
multimeter set to 200.
Old Coil = 1.5
New coil= 3.1
I then set my multimeter to 200k
I then put the red probe on the + post, and the - probe in the center tower post
Old Coil= 8.5
New Coil= 9.5
I have not done any tests with the multimeter while it is on the boat yet.
However based on these tests results, Natemoore are you saying this coil can be run on my delco distributor with the points and not using the resistor wire?
Here's what he wrote:
Pertronix Tech Rep Explanation
It's not acting like a short to ground. What you are seeing is the resister
wire at work in the ignition circuit. The points and Ignitor work in the
same exact way. They take the negative side of the coil on and off ground.
This is easy to explain but is going to be long winded. So here we go:
A resister only works (drops voltage) when it has current drawn
through the resister. So in less you have a something drawing current
through the resister (i.e. the Ignitor or points) you will read 12-volt at
the end of the resister (coil positive in this case). Current gets drawn
through the resister when ever the negative side of the coil goes to ground.
The negative side of the coil goes to ground every time the coil is being
charged up to make spark. Depending on the resistance in the resister and
the resistance of the primary of the coil, well determine how much voltage
you see on coil positive. So, depending on whether the Ignitor or points are
in the open (off ground) or closed (going to ground) it will determine what
type of voltage you see on coil positive.
In your case the Ignitor just happens to be lined up in the closed
position. So, when you connect the Ignitor red wire the circuit is completed
and goes to work. The same would happen if you hooked and unhooked the black
wire. Same should happen if you hooked the Ignitor red wire to battery
positive completely off the coil. In fact you can make the same thing
happens without the Ignitor. Disconnect all the Ignitor wires from the coil
and place a jumper wire from coil negative to ground. Turn your key on and
you will see the same voltage drop. That is because the current is being
pulled through the coil and dropping the voltage across the resister. This
is all normal and shouldn't be worried about.
When ever a resister is in the ignition circuit it must be bypassed with the
Ignitor red wire. Like our figure 3 wiring diagram. So, the Ignitor red wire
goes to the 12-volt side of the resister or in the case of a resister wire
to the location that this wire starts. In a mercurser that would be at the
choke. (See attached wiring diagram)
Now on the coil resistance. It just so happens on 4 cylinder application
the Ignitor and points have the same spec. So, that will make this easy. The
Ignitor and points can only handle 4 amps passing through them or they will
burn out. You can get the 4 amps in a two different ways. One is by using a
combination of resister and resistance in the coil; the other is by just
having the correct amount of resistance built into the coil. One way isn't
really better then the other in my opinion. Some opinions very on this fact.
To only get 4 amps across your ignition system that would require
3.0 ohms. You can figure that out by taking your battery voltage and
dividing your resistance to determine amps. (12V/3.0ohms=4amps). In your
case mercuser used a 1.5 ohm resister wire and a 1.5 ohm coil adding up to
the 3.0 ohms. So, removing the resister and running 12-volt to the 1.5 ohm
coil will cause the ignition (Ignitor or points) to handle 8 amps. Double of
what it can and it will burn out. Race applications are different because of
RPM range and amount of time spent in the charge cycle. Trust me you would
never use it in a 4 cylinder boat application.
I hope this answers your question. In short you should be placing the
Ignitor red wire on the incoming side of the resister wire at the choke. And
you can't remove the resister in less you change the coil to a 3.0 ohm coil
or you will burn out your ignition.
