Just got the individual gap tester. I have a 6 cylinder motor. I understand you remove all of the plugs and ground the remaining 5.
What is the best way the ground the other plug wires?
If you were doing this all the time, you would get a tester that does all 6 at once. Othrwise, the best way is make up some wires with alligator clips on both ends. Clip one end in the boot and the other end to a ground.
If you have electronic ignition it's pretty important to be sure they are grounded. You might make up a simple device that has 5 quarter inch bolts sticking out of a piece of wood....all wired together with an alligator clip on the end of a wire.
Push the spark plug boots onto each of the five bolts...and clip the alligator clip onto an engine ground.
Well I found intermittent spark on the port side, top and bottom, the middle looked ok.
I think this might account for the occasional miss I have.
I have another thread for that, thanks for the help.