[Motofool]

Originally Posted by FvnnyL3tt3r1ng

Are you saying to insert a screwdriver head first into the cable and observe an arc from the shaft of it?

I didn't know spark could be inhibited by high pressures. Learned something new today.

Yes, but keep your fingers from becoming a conductor themselves.



It is called Paschen's Law: "For a given gas, the voltage is a function only of the product of the pressure and gap length."

http://en.wikipedia.org/wiki/Paschen%27s_law

Copied from:
http://www.dansmc.com/electricaltesting.htm

"When you check for spark, the spark must jump at least 1/4" (.250") or more outside the engine. Just laying the spark plug in the plug cap, on the cylinder head, and getting a spark across a .030" gap is no good. It takes a lot more power to jump a gap under compression in the engine then outside the engine under no compression pressure. Also, if it's electronic ignition, you must spin the engine to at least three or four hundred RPM. Any less and the anti kick back circuitry in the CDI black box kills the spark."