There is no substitute for completely disassembling a carb and cleaning it by hand.. brushes and toothpicks and soft wires to go through all the little holes and strong compressed air to blow all the passages clean.
A truely clean carb is a most important thing on these little engines. Microscopic bits of crud can cripple a bike. And on some bikes its such a pain in the ass just to remove the carb.. cleaning it properly with visual inspection under magnification and strong lighting is well worth the effort.
I think you will discover where it's clogged as soon as you take a close look at it.