Profound disappointment.

I took one of the rebuilt carbs and tried swapping it back to the Banana Bike. 

I checked the plug...there's spark.  The carb is getting fuel.  In fact, the bowl level when disassembled looks about right.  It just wouldn't fire.  Now, I've rodded out the idle jet that was clear anyway as was the emulsion tube.  Everything is tight with a fresh seal on the bowl and cap and new o-rings in the intake mating surface and the filter which didn't leak at least.  Nothing leaked.  Nothing went into the engine as well.  Other than the slide moving a little stiffer than the rest, I can't find any reason it wouldn't fire. 

I did re-install the chinese carb that resulted in a happy idle on the second kick to ensure the complete demoralization.  It's cold and dark enough that I gave up.  I'll try swapping the other rebuilt carb Monday and see how it goes.  Daylight would be nice as well.  I'd really like to get the Banana Bike back on the stock filter.

Any thoughts?