soaking a very dirty carb in chem dip will NOT clean it, nor will just adding a rebuild kit to it
ethanol builds a varnish like coating to many parts and passages, that the chem dip does NOT remove or clean or clear
you actually need to get more involved that just a soaking and spraying!
so carb could still be bad here!
if your hearing air, normally that means a rubber boots are torn or damaged,??
but if your spraying , say starter fluid about area while running and NO difference that sort of rules that out!
is this atv snorkeled?
or stock air box yet?
is exhaust pipe sealed well to the motor and all connections?