Too much ... gas

[Northern...er]

Float height's ok... cleaned all pin holes/jets... adjusted the pilot screw to spec; installed a new needle valve last winter...  BUT... I have to remove the air breather cover to start machine, as SO MUCH GAS seems to be spitting thru the carb...  With the cover removed, usually starts in a few pulls... and I can replace the cover in a coupla mins, once it warms up ...
What haven't I tried?!