Welcome, it could be caused by an airleak have you checked that out yet???
On my half fairing cag I bought running for 30 bux a few years back from a member here I had installed a 14/14 rep carb on it and it had to be rejetted and adjusted quite often to get the engine to run right day to day or when it wouldnt run right just chuck it back in the basement and grabbed one of my trusty piston ported rides like X1/X2 harleybike or stand-up scooters because they always started up and were easy to keep in tune and offered more fun....My guess is the air leak.. if it was running fine with the carb settings before you stored it.. Try to get it to idle a little and spray carb cleaner around the intake manifold.. If it dies you have a air leak there..