Tainted Spark from SparkPlugs

[Tinkertoy]

I was over a friend's house the other night....he had his Ohm meter out to show me something I never ran into before....Firstly, I'll share with you guys : gasoline fowled plugs with soot from too frequent starts and stops from a choked engine will cause an engine to not start....I worked for Oldsmobile for 20 years and experienced this time and time again on the new cars on the front lot....these were brand new cars and would not start unless we pulled the plugs and sandblasted them...the car would then start and run like a champ... now, to get back to my friend...he discovered in his lawnmower engine, that ceased running because of no spark...he pulled the plug and not like the soot fowled Oldsmobile sparkplugs, this one looked clean...he put his ohm meter across the threads and the other lead to the electrode and found no continuity....has any one else witnessed this?? He sandblasted the plug and retested it....like brand new again and the lawnmower fired right up... he thinks it was from ethanol in the gas.

[Rick Spivey]

There shouldn't be continuity from the threads to the electrode. That is why the spark jumps this gap.

[Tinkertoy]

I misprinted or mis interpreted what electrode.... the negative tab and the threads...not the center electrode that the spark jumps across....the part you bend to create an air gap and the threads....never seen this before