Yep, sounds right. Been there,done that a couple times. I was lucky enough to just take the bottom of the carb off and spray it full of carb cleaner.Sounds like your needlevalve/float is sticking. Trash under the needle valve is possible. For a quick fix, try tapping on the carb with a small wrench or something and see if it stops. To fix it for real you'll probably end up taking the carb off and cleaning it.