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There is actually a tool called a spark gap tester that you can set the correct gap and see if it will jump the ap. Also there is another tool that is a light that you put in line with the coil wire and see how bright the light is. Without either of those tools, you will need to use a screwdriver and your judgment The spark is supposed to be 30,000 or more volts(I am not kidding), so it will be a good healthy spark that should be able to jump an 8th of an inch or more. If it is a puny little spark that looks more like a static electricity discharge, it is too weak. If you touch it, it should light you up really good. It wont hurt you if you do, because even though it is tens of thousands of volts, it is at such a low amperage, that it doesn't have any punch. You will just know you have grabbed something that you shouldn't have. I tell you this because I know of guys that have used that method to tell how stron the spark is. Anyway, use a screwdriver against a ground, and see how far the spark jumps.

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โˆ™ 2014-07-04 16:04:54
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Q: How do you tell a good spark from a bad spark when testing the ignition coil wire to see if there is spark?
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