I would start with another plug first. You could also make sure that the plug wire is installed properly at both ends, (inside the cdi box and the sparkplug cap) by pushing inwards while screwing the wire to the right. You will notice that the wire "screws" onto what looks like a nail, is this poking into the right spot, making contact with the wire. You could snip a 1/2 inch off each end of the plug wire to allow you to make sure that you are making a good connection. With any luck, this may help you. Good luck!