Spark Plug Options

The terminal ends on the IW20TT Denso's DO NOT UNSCREW.
some history here. - The original KZ1300 came with BP6ES plugs with 5 K ohm resistor spark plug caps. the resistor in the spark plug caps is there for electronic noise suppression. An option for plugs was the BPR6ES spark plug which also include a 5K OHM resistor in the core of the spark plug for electronic noise suppression. If the BPR6ES resistor plugs were used in conjunction with the 5K ohm resistor spark plug caps, they would work BUT, there's now 10 K OHM resistance in the secondary of the ignition coil which will cause the coil to have to work harder to overcome the resistance before ionizing the air gap and causing a spark to occur. A weak ignition system MIGHT fail to ignite the fuel.
5K ohm resistance will suffice for the noise suppression, SO running a resistor plug like the IW20TT with a standard plug wire cap (no resistor) will get the job done and not having everyone's radio buzzing as you fly pat them.
if you want to run the IW20TT's then change out your plug wire caps for the old metal spring cap.

I'll be running solid core copper wires with the good old fashioned spark plug wire caps as per pic and relying on the 5 K Ohm resistor in the sparkplug for noise suppression.