Is it the right front plug wire? if it is, then it may be arcing on the cable that lays near it. I had that problem on mine...
to fix it I bought a length of fuel line and slit it length-wise, then I placed it over the cable and secured it with zip-ties.
if it is not the right front plug then I guess you will need to change the wire out
new tires (OEM Stones) 6/2008
home made floorboards (knifemakers styling)
stator replaced 6/2008
cobra slashcuts 7/2007
clear alternatives brake & tailight 8/2008
Added Mutazu hard bags 3/2009
added customLED load equalizers for the bags LED lights 3/2009