Champion Resistor Spark Plugs

[harleysportster]

Here is info on the 2 different styles of resistor plugs from Champion.
JD recomended N-1 (for U.S.),QN-1 (for Canada)plugs for the 76-78 cyclone/liquifire.
The standard R type resistor plugs could be a problem.

CDI (Capacitive Discharge Ignition) for outboard marine motors is basically a refined version of the old magneto ignition system, except the points have been replaced with electronic circuitry. CDI is used on some (not all) late model marine engines such as Johnson and Evinrude, and some late model motorcycle engines. Do not use a "regular" resistor type plug on a motor with this type of Capacitive Discharge Ignition as this will cause misfire and poor performance. Rather, make sure to use a plug with an inductive type resistor (such as a Champion Q-type resistor). Use of non-inductive resistor type plugs on these motors can create an open circuit within the spark plug (it will become a dead plug).

This could account for the NGK resistor plug failures.