Do you have to let the electrode touch any metal surface??
If so what is the reason for this???

 

touch is not best. Close to touching is better it allows you to see/hear the spark. The reason is to complete the circuit. think of it like a light if you hold the bare wire three feet away from the lamp the power wont get there.

 

To test spark I just put an insulated screwdriver into wire, then so that the metal has an arc distance between it and a ground on the car. You can then do this on your own as you can position the screwdriver so it's visible from the driver's seat.

 

YA i do the same thing with the screwdriver thing. It works fine. If im lazy i just get one of my buddies to hold the sparkplug...jk jk...i wouldnt do that to my idiot friends.

 

i saw a video of a guy cracking a dist. cap on a piston car.. sent him about 30 ft back n blew him right out of his boots... if u dint happen to like the person i say let em hold it

 

My dad got me really good when I had my hand on the a pillar of my FC, started cranking the car and bam, **** ****** that hurts.

But like previously stated, don't let it touch, get it really close.

 

I was pulling a plug wire off the dizzy on a running engine, I was fine as I was leaning against the fiberglass fender. However, the kid watching me had one hand on the open hood and his shoulder touched mine. We were both shocked, but he got the worst of it.