Most versatile and efficient spark tester

[geoffwga1]

Time to build=10-15 minutes.Cost =Zero.efficiency=100%.

Could just as well be two nails but the copper is easier to bend about and set the gap..

 

[HighTrim]

If you want to make a versatile one, make one for multi cylinders. This was made from a distributor cap and a pop can.

http://s691.photobucket.com/user/snapc33/media/boat/MVI_1450.mp4.html