About 45 minutes after getting the GS back on the street after re-running all new fuel lines on the freshly rebuilt carbs, the speedo fluttered and died.  So, speedometer work, what's the first thing I should do to try and fix this on my own?  Note: I had the front end apart about 200 miles ago to rebuild the front forks. 

The other issue, I've got jetting copied from old Srinath posts for my setup, and the bike idles at 3k once warm.  When cold, it needs about 20 seconds of light choke, and settles to an idle of about 1200.  I've got about 2.5 turns of the mix screws, and have used just a bit of the throttle plate opening "speed screw" to get it to 1200 RPM cold.  I guess my question here is, should I run the speed screw out a bith and turn the mix screws in, or what?   

as for spedo check that its tightened at the wheel end and speedo end, if that fails then pull off the wheel and check the speedo drive spin the insides and see if the speedo moves, if it doesnt check the cable is in place properly and the inside where the cable meets the drive hasn't been rounded, as for carbs get the bike warm, turn it off remove the plugs give them a clean put them back in and restart for a couple of mins, turn off and remove, then you should see if its running rich or lean at idle and should be able to adjust mixture from there, what are you settings?? can/filter/jets

you should set your idle speed to 1200RPM once it's warm. Go for a 15 minute ride and then use the throttle stop screw to set your speed. As for the speedo, your cable probally came loose or broke.

The carb and bike setup is, #150 main jets, #40 non-bleed idle jets.  2.5 turns of mixture screws.  Full Vance & Hines exhaust and a K&N lunchbox airfilter.  I used a single #4 washer on the needles.