In joe reeves WOT procedure it talks about using a spark tester and setting it to a 7/16 gap what is the reason for this step do you have to do this when you set the timming and why or what would it hurt if you didnt do it
A 7/16" gap is what is needed to check for good spark for ignition, if it can jump the 7/16" gap on a tester witha nice hard blue spark, you know you have good spark in your combustion chamber on your plug.