Any chance it could be an Ethanol related problem............. i.e. too high a %age of Ethanol in the petrol thus causing the plug to get too hot ............. just a suggestion
I'd say it's not changing the plug thats solving the problem its the time it takes to change the plug. Its either the LT coils, the pick up, thet CDI (augustos don't like some CDIs) or the ignition switch.
I don't want any oil as I feel the guys on here give so much info that they could profit by away that they are entitled to ask us the odd question without paying for it.
I've had an electronic ignition that repeatedly killed ignition switches as spikes in the ignition were overloading the system... and the ignition switches seemed to be the weak link. Symptoms were very much as you describe.
I still ride this bike today, not wanting to change the ignition, but have resorted to riding it with the loom's green removed from CDI, meaning that the ignition is always live and the key just works the lights. Not an ideal situation for a customer's bike! As J1MS has suggested, removing the loom green from the CDI to test whether is has an influemce on the problem.
i had the same problem but ive got a m tec ignition box ,turned out to be the flywheel, af light one , changed it for a indian light one its been fine ever since :anbrgin;