You cannot test champion plugs with an ohm meter!
I was wrong about silicone carbide:
From champions own literature (with emphasis added by me):
SAC-9 Suppressor
Champion developed the SAC-9 suppressor in the early 1980’s. This extremely reliable
resistor/suppressor is formed from strontium carbonate, aluminum oxide and copper
oxide powders. In fact, out of billions made, not a single SAC-9 suppressor has ever been found to fail in service. They are used in Champion “R” type resistor plugs. An
important feature of Champion plugs with the SAC-9 suppressor is that the resistance of
the plug cannot be accurately measured with typical low voltage ohmmeters.
This resistor is a proprietary type (hence why tempest do not use them) and very little info is available except that they are the resistor used in every champion plug with a R designation (aviation plugs).
As for magneto operation the primary coil is 200-300v secondary is 20-30,000V however this is only used for a nano second at the start of spark when ionization of the spark gap occurs. After this the spark voltage decreases exponentially. Thus excessive voltage in the coil is more likely to be created by excess plug gap which increases both the voltage required for ionization and the duration that voltage is required for.
As for gaping fine wires, generally they will need it once in a life. At approximately half wear life they will exceed .019". they can then be delicately re-gapped. I have not broken one yet. But would much rather risk breaking a fine wire than operating with too large a gap (with increased resistance at the point of spark gap ionization and thus excessive voltage and heat.
Your only other option is to throw the plug out when it exceeds .019" gap which is a waste when you can re-gap it with a $10 tool and 5 minutes of patience.
Tempest advocate for resistance testing of all plugs and no re-gapping for two simple reasons: They do not understand how the SAC-9 resistor works (and champion wont tell them) and they would rather sell another $70 plug.
Champion do not tell you NOT to test their resistance for two reasons; You should be doing what they (not their competitor) tell you to maintain their plugs and if you buy another $70 plug because you didn't that is their gain.
Creamy,
Perhaps the inventor of taser doesnt know that most variable resistors are subject to a sustained voltage limit after which the material fuses and goes to infinite resistance and that by putting 50,000V across it he was effectively making it open circuit with greater resistance than the air gap. The tazer then did exactly what it was designed to do and provided a high voltage current at low amps which ionized the air gap (which is easier to ionize than the pressurized fuel air mixture) between he electrodes and bypassed the resistor. Use of a voltage in the 12-30k range would have produced a better result.