Moped Army

I got one spark once from this set up and cant figure out whats wrong. As far as I can tell its all set up right (included a picture). I used the same ignition coil thats treats sells with this setup. connected red to red wire, white to white wire (using a terminal block). both grounding wire are attatched to clean shiny metal - no rust or paint. The kill switch has been dissconnected so its not a factor. The tail light and headlight are connected through a voltage regulator to a switch and that works perfectly.
the one spark I got was from the spark plug cable with no boot on it hanging about a 1/4 inch above the cylinder head. A bright blue spark jumped the gap between the end of the cable and the cylinder head and that was all I ever got.
I do have a multimeter if I can use that at all to troubleshoot but I have no idea how to use it.
Any idea or suggestions please help Im out of ideas.