you need to find outy if its spark is missing when its broken down,when it does it next time make sure you have a 21mm plug socket and undo the plug take it out put it back into the ht cap earth it on the frame or engine on a metal part and kick the engine over and see if it sparks,if it doesnt i would say it very likeley to be the primary ignition coil in the stator coil assembly ,if it still sparks them i would look at the fuel flow try it with the petrol cap off in case there is a negative pressure(vaccum) build up in the fuel tank that is stopping the flow of fuel to the carb.let us know please what you find.
adam bike doctor
January 2010
could be the coil or HT lead breaking down. I would fit a new plug as well. Check your airfilter while your at it
bb
January 2010
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix motorcycles.