Hope I can describe this clearly, because I don't have my digital camera handy. 

I have my carbs off my bike and am giving them a thorough cleaning.  In each carb, there are two air jets in the lower, curved section of the venturi.  One of each pair is offset a little to the right of center.  I understand these to be the pilot air jets.  I can stick a thin metal wire almost 1 1/2 inches into these jets, so I'm pretty confident I've got them unclogged.

Each carb has a second air jet centered exactly below the throttle valve.  These I understand to be the main air jets.  Despite repeated blasts with carb cleaner, I can get my thin wire no further than maybe a 1/8th of an inch into these.  This occurs on both carbs.  Either these two main jets are equally (and coincidentally) plugged up good, or they are narrower than my cleaning wire (and the pilot air jets).  Or, maybe they only go in 1/8" and take some sort of sharp detour my cleaning wire can't negotiate.

Again, I get push that wire a good 1 1/2" into the pilot air jets, but only 1/8" into main air jets.  Why?  I would have thought the pilot air jets would be narrower and therefore more likely to clog.  What am I doing wrong?

Thanks in advance, fellow GSers.

Major,

The idle orifice takes an immediate 90 degree turn inside the casting.  If I recall correctly, it is in the same drilled passage behind one of the air jets you're referring to.

Using the straw on your carb cleaner bottle and safety glasses, spray cleaner into each of the air orifices.  If you see it burble or jet out the little orifice under the throttle plate, you're good to go.

Thanks GeeP.

I let the carb spray soak into those "clogged" jets for several hours.  Now I can distinctly see the bright brass jets and how they narrow considerably, I now see why I couldn't get a wire further into those. 

But I can't get carb spray to burble out under the throttle plate in any of the air jets, even the ones that I thought were nice and clear.  Yes, I'm blasting it through the straw.   Something gummed up further inside maybe?  Unfortunately, I don't have an air compressor.

I think I need to get at the fuel jets.  I think I'm supposed to be able to remove these grey plastic piston guides up through the top of the throttle bodies.  But they're not budging.  What GS voodoo do I need to get those loose?

FYI: It's amazing how much more sense all those old GStwin carb/jet/float bowl posts make once you start doing the work yourself.

Air jets are well diagrammed in your manual carb schematics.
The white for air, the - for gas and the dotted thing for mixed. Look in that, I am almost sure these jets are smaller than your wire and not much deeper than the 1/8th. BTW the thinnest wire you can get is almost right for the 40 pilots, these air jets are very small.
Cool.
Buddha.

I removed those plastic inserts when I cleaned the carbs. Now I'm wondering if they failed to get a good seal when they were reinstalled and that's somehow contributing to my floating idle problem.

How did you remove those inserts, gearman?  Mine are in tight and I don't want to force anything before I'm sure there's not a screw or clip somewhere I'm supposed to remove first.

I don't recall how they came out but I'm pretty sure there was a thread or link on here that explained it. Whatever you do don't break 'em because they don't show the part on the oem fiche which tells me it's part of the carb body.