Does it really matter?

Had Dynatek DW-300 copper core wires (w/NGK resistor caps) for a while, and I just put my Taylor  resistor wires back on...

But, does it matter?



Running Denso NON-resistor plugs

🤔

Not sure about the Dyna (question for them) I suspect it has more to do with being a legal requirement in many countries due to the electronic interference it causes without

Typically, you want about 5000 ohms of resistance in the system for each plug.  Pick ONE: resistor spark plug, suppressor (resistor) plug wire, or a resistor type plug cap.  Stock Kawasaki used a non resistor spark plug and plug wire, with a resistor plug cap.

That said, some bikes, like later year 550's, moved to resistor spark plugs late in their product cycle.  So those bikes used both a resistor plug and a resistor spark plug cap.  No other changes occurred in their ignition system, that I know of, so it seems the system is at least somewhat tolerant to more resistance than considered normal.  Of course, this is unrelated to the Dyna...or maybe not.  They typically follow the same.

I have also seen similar instructions with regards to plug wire construction/coil ohms/battery output on MSD ignition boxes. If a manufacturer has designed these products they generally know what works best with them as they also do rigorous field testing. Racers use these parts to make a living, so I think it matters.

I can't tell you how much resistance you need.  I would follow Nessism's advice on that. 

But I can tell you why it might matter.

Some background.  A spark generates/releases a wide band of radio frequency energy.  Early radio transmitters (like on the Titanic) used a spark gap to create the RF transmission.

Spark energy can interfere with AM radio, but it can also interfere with modern electronics.

Adding resistor plugs, boots, or wires reduces the energy of the spark somewhat, but it also reduces the amount of RF energy generated and the ability of that energy to radiate out from the spark plug by making the plug wire a less good antenna.

A KZ that came with points is basically completely immune to RF interference.  Those mechanical switches don't care at all.  So there was no need for resistor plugs or wires.  That's why there were so many Z1s in Mad Max.  It's the perfect post-apocalypse vehicle.  

Of course, if you put on a windjammer and AM radio, you'll hear a lot of noise.  But are there still radio stations after the apocalypse?

Even the Dyna S or III are mostly immune to RF interference.  These use magnetic switches that don't really care much.

But the Dyna 2000 is very different.  This uses a modem microcontroller (embedded computer processor).  These can be very susceptible to RF interference.  RF noise could cause false trigger readings for the crank trigger, the processor could lock up or reset, and if it's strong enough it could damage the processor.

If the ignition box reset and rebooted while riding, I think it would make most folks pretty grumpy.  

Given that the Dyna 2000 was available for many bikes that originally came with points, there is a good chance those bikes wouldn't have resistor plugs or wires.  It seems Dyna was trying to make sure that folks added those noise suppression features when they installed the system, to avoid potential noise issues.