motorcycle sat for two years and now it won't start?

I have a 2004 Kawasaki Vulcan. It has sat in my garage unused for about 2 years. The battery was disconnected and the fuel was drained. I'm trying to sell it now, but it won't start. The battery needs a charge, so I hooked it to the car and teh bike turned over, and over, and over, but wouldn't catch. Any suggestions? I have several buyers waiting, but I think they're assuming the bike will start.Ok, here's what I've done so far. Pulled the plugs and cleaned them and sprayed out both barrels on the carb. I sprayed some fluid in the airbox and the bike would start for about 2 seconds and then shut off again. It seems to me it's not getting fuel, but why? This is frustrating because I have a buyer waiting for it and I can't get the thing running. And I'm in Germany so it's not easy to find a place to work on it.