First check for dirty terminals, ie clean them. Then check your battery to make sure you have charge. If they both check out OK then check your lead from the coil to the plug. Finally you might have to get an auto-electrician to run a multi-meter over it to source to problem. There are no freebie manuals for your model, but have a look any way, one may give you a guide:
http://www.carlsalter.com/motorcycle-manuals.asp