Butane gizmo. Got it at a yard sale. Not clear it ever worked.
Is full of Butane.
The orifice is two concentric brass parts screwed together
with a tiny metal disk in between. Disc is very thin and about .150
diameter. Has a TINY hole for the orifice.
50X microscope is the best I had handy. Can tell there maybe
was a hole..maybe...

How can I clean or ream such a tiny hole?
How did they manufacture it in the first place?

I'm guessing that the hole has to be very symmetrical
so the jet of gas goes down the center of the tube that mixes the air.

Not worth fixing, but could be a learning exercise.