O, when you were cleaning it,you took it completely apart?
the the nibble inlet bolt too? if so,then you would have seen a brass screen in the hollow bolt,if you don't have one then someone removed it.(you should have one)
on the carb,where the hollow bolt goes in, there is another fuel hole that runs into the bowl,it's where the float pin is, check that too. from the float side, also, check float that it moves freely.