I don't have the $269 Yamaha special tool for testing spark gap. I am using a test light. I clamped the ground lead to the chassis. On cylinder 1 the spark jumps out of the coil pack a little, cylinder 2 I have to place the probe inside to get it to jump. I have tested the crank sensor and it tested good. I watched a youtube video and the spark would jump more than what I am seeing. But the video was on and automobile.