As you say It sounds like you are not getting fuel in the idle circuit. I suggest you remove the idle jet and make sure it is clear, they are quite small. If you screw the idle needle right in and can squirt carb cleaner with a tube or air line into where the idle jet seats, it will blow any muck back into the float chamber. If I remember correctly those bushes a quite small and pressed in, you would wreck them trying to remove them. I suspect it’s just dirt somewhere, have you got a fuel filter in the system?