On Friday, May 22, 2015 at 7:32:30 PM UTC-7, mike wrote:
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?

You might give it a bit of suction (syringe and a small-bore teflon tube
was how we did that kind of thing in the lab). Or, paint it with glue that
doesn't stick to brass, then peel that off when dry, and hope it pulls the clog
out.

Laser, EDM, or #80 drill are all kinda standard. Perhaps also chemical etching.
One cute way, is to stack a dozen pieces of shim, and poke 'em with a needle.
Then look at the top one. If the hole is too big, look at the second... and so on.