need more info. suddenly start this? been running fine? how old is the gas? hard to get started? Have you even messed with the idle screw?
carb cleaning is in order first up...and when you have the carbs off purchase some new insulators...(the little rubber hose looking things that are stuck to the bottom of the carbs... clean real good and do a re sync....
It does sound like it sat for a bit, pluck them off and clean the jets and ride. More info will help but have done this reapair dozens of times this year, all to common. LINK. http://vfrworld.com/forums/mechanics-garage/22449-cleaning-carbs.html
