How to rule out a Spark Plug as your problem

A very simple but highly effective method(when done properly) which I have always used to confirm if a spark plug is, is not the cause of engine starting and, or performance problems. Why run to the store and buy a new spark plug as a gamble, which may not be inexpensive, when you can verify if the plug is the problem using your digital multimeter. Save time and money I decided to upload this video when I discovered that not too many people knew about this simple, effective spark plug test. RULE OUT SPAR