Wilsons Sandbox

Here's a video of me trying to start my KLR 650: http://www.youtube.com/watch?v=TawDc6loYQE It doesn't seem like the battery is low, because my battery has died on my several times before. What's unique here is the rapid-fire, machine-gun-like sound as the green light goes on and off super quickly. Background:  (1) Six days ago, when I last started the bike, there was a loud pop/bang from the exhaust, but it started OK.(2) For the last six days the motorcycle had been sitting there with the fuel supply valve in the "open" position (accidentally, of course).(3) Right before the video above, the first time I tried to start the bike, there was a pop/bang from the exhaust, then it started doing what you see in the video. Is the carburetor just messed up from the fuel supply being open for a week? Is there any way I can fix this without having to do a full carb clean (this happened to me once a long time ago, when I let the fuel supply valve open and didn't touch the bike for 3 months, and the carb clean cost me $400 , so I'd like to avoid that if possible. I don't remember the symptoms being the same during the earlier incident, but it was a while ago so it's hard to be sure). Thanks,Elliot