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How do you test a coil?


Les

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Without specialized equipment, you don't. A simple Ohmmeter test *might* tell if it is bad but will NOT tell you if it is good. Best method is "in situ" (I bin waitin 27 years and 4 months to use that phrase.) Remove the spark plug, reconnect the plug wire, clip, clamp or otherwise affix a wire from the plug threads to ground. Put plug with wires into clear *plastic* jug or bottle. Crank engine, look for spark between electrodes. Plastic container is to keep fuel from open spark plug hole from igniting. You may want to open the plug gap by around .005 more than spec. This is because in rare instances a plug will fire in open air, but not under cylinder turbulence. If it fires in open air with a wide gap it should be ok at normal gap in the engine. JackP
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les insted of buliding all that nosence as Jack has sugested buy a spark tester they run from $5 or up $20 for a good one
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Karl_Brandt
I've quick-checked a coil by taking the plug wire off the plug, pushin back the boot, then holding the metal end of the wire a short distance from a clean metal body part, simulating a spark gap. You can also just hold onto the wire and crank the engine....that'll tell ya in a hurry if you've got spark! (not for the squeemish).....
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