That's a good way to check for spark. The cheapest easiest down n' dirty way is pull the cold side plug put it back in the HT lead and rest the plug body on the head on the fin beside the spark plug hole. Take some duct tape or wire to wrap around the lead to hold it to head so as not to fly about from vibrations. Then start it up on one cylinder and look down ,observe the plug for firing sparkage or not. If it was sparking then put it back in and move analytical thinkings to carb. :|