Somethings not right here...I rebuilt this motor. Set the timing by LeeRoy's Ramblings. I checked spark by grounding the threads on the head and pulling the rope. The bottom plug sparked but the top one didn't. I'm thinking uh oh need a new coil. But my buddy said maybe the stop switch is cross wired. Held the stop switch in...sure enough...the top plug fires and the bottom didn't. What the heck? There's no way to cross the wires on the stop switch. Anything? Maybe timing is off?