1978 CB750 F3
Pamco Ignition with 3 ohm Dyna coils and Hondaman resistor pack
The resistor pack is not necessary with the PAMCO ignition and those coils. In fact, they will reduce the current to the coils and produce a lesser spark.
The PAMCO draws about the same current as points, even with a lower Ohm coil. Here is a description of the current draw for a 2.5 Ohm coil vs the stock 4.5 Ohm coil with points.
The stock points coil has a primary resistance of 4.5 Ohms so when the coil is on, the current would be 14/4.5 = 3.1 Amps, but the coil is only on for slightly more than half the time with a 190 degree dwell angle, so the average current is 190/360 = .53 X 3.1 = 1.64 Amps. The average current is what would affect the contacts of the kill switch, not the peak current.
The 17-6903 "Ultimate" coil has a resistance of 2.5 Ohms, so its peak current is 12.8/2.5 = 5.12 Amps but the PAMCO rotor has a 120 degree dwell angle so the coil is only on for 120/360 = .33 of the time so the average current is .33 X 5.12 = 1.69 Amps
However, in both cases, there are two coils powered by the same kill switch, so the average current that the kill switch sees is 1.64 X 2 = 3.28 Amps for points and 1.69 X 2 = 3.38 Amps for the PAMCO. That's only .1 Amps more than points.
So, a 3 Ohm coil will draw less current than the stock points setup and you will get a hotter spark without the resistors.
I use 14 Volts for the points because the kill switch typically drops about .5 Volt. The transistor in the PAMCO, as in all electronic ignitions, drops about 1.2 Volts so I use 14.5 - 1.2 - .5 = 12.8 Volts for the PAMCO.
