Alright so I had a thread on this a few months back but figured I'd have better luck with a new one. Anyway, baisically my gs500 is a B***H to start and won't idle below 2000rpm. Rather than describe my symptoms I posted a video up on youtube, here's the link. By the way this in about 50 degree weather. The problem is worse the colder it gets. Spring is coming and so is an anticipated long-distance ride  so I really want to get this thing running right.

Sounds like a dead battery; and at under 2K RPM the charging circuit wouldn't necessarily be putting out enough power to run the bike and charge the battery

I wouldn't be so sure about the dead battery. I've road all of last summer on a bad battery. When it was cold, sometimes it didn't even have enough power to turn the starter motor. After a push start, it would run fine. Having said that, I don't have an alternative idea.

Also, I'm having the EXACT the same problem right now. I'm using a freshly charged, new battery, and have the exact same sound. I also just did a valve adjustment, drop-in filter, and re-jet.

On of these yoda's has to have an answer.

Battery is new, so are the spark plugs, and I cleaned out the jets (carb looked pretty clean though when I took it apart) and put new gas in. Next step is going to be a valve adjustment / just looking to see if there is anything wrong in that general area. Also rode it about a mile the other day and randomly lost all throttle response going through a turn accompanied by some nasty backfiring. Throttle eventually come back but pretty sure that was a related issue.   

I i discovered that i had a vent hose routed wrong. After fixing it, my bike is running better (but still not great as I still have to adjust fuel/air and idle screws).

The line in particular that i crossed is the vent line from the top of the carbs. I had it running to the drain on the bottom of the fuel tank. Anyway, these diagrams might be worth a look through see if you crossed anything like i did...

http://www.bbburma.net/FuelHoseRouting.htm

http://wiki.gstwins.com/index.php?n=Main.HoseRouting

Clean the carbs and lines .... If there is a fuel filter on the lines .... Take it off.... Make sure your lines are to the right spots....and not split, cracked or leaking .... Make sure your tank petcock is opened properly ... Straight vertical!

Carbs looked ok..... Not having a go at you here.... But that has been a popular statement at times for non running bike threads .... Clean.... Clean!!!!! .. Check jets ...... Clean them again too ...

Then when everything is so clean that even rainman would say damn that's clean!! .. Check your float height settings, needles and settings

It really sounds like the fuel is only part there....