I had an interesting ignition system problem about 20 years ago .
When the temperature dropped below 55 F, 13 C the engine was hard to start first cold start of the day .
The fuel supply had just changed from MTBE to 10% ethanol a few months earlier in warm weather .
I blamed the ethanol on this .
To make a long story short, the primary coil circuit had .7 ohms should be 1.5 ohms, OEM dual output coil, second generation the red and black coil .
The multimeter I had showed the correct value, I took the coil to work and used a calibrated meter, that's when I found the low resistance .
After that, I bought a Fluke multimeter .
I went to Dyna brown coils on all the bikes, no issue with them yet .
I've used NGK ignition leads for 20 years, no issues with them .