ok ill tell you exactly how to suss out the problem
1st take off the panel behind your heels as you sit on the bike
2nd you will see the cdi/coil assembly there it will have a green ,red and white wire on it
bianco =white rosso=red verde=green
the green wire has two wires if you look closeley one goes to the stator assembly in the engine the toher green one goes into the loom.
3rd find the loom green and cut it somewhere you can join it up again easily see if the bike sparks then !
4th if it doesnt then the cdi/coil is faulty or the stator coils assembley has a faulty primary igntion coil
5th if it does spark with the green cut then the problem is either the grenn wire touching earth on its way to the igntion switch or the electrical part of the switch is faulty.
try running a length of wire from the green wire at the cdi to the green on the switch and see if that solves it if it doesnt then the switch is faulty.
all avenues covered !good luck its a very simple set up
p.s check the multi plug at the left hand engine cover incase it has come apart from the loom.
adam bike doctor(of milton keynes motorcycle centre), January 2011