If the plug thing does not turn out to be the issue you need to pull the jets out of the carbs and clean them. This has happened to me a number of times over the years and I pull all of them and clean them while I have the carbs off.
2004 KTM 950 Adventure S
2007 Ducati 999S Parts Unlimited
2012 Ducati Multistrada 1200 Pikes Peak