[smileyman]

Fresh fuel would be my first thought. Water will float to the top and you get gas until the level drops...

Possibly something in the tank or lines may have filtered (filter?) thru to the carbs and gotten a needle or float stuck.

When one sits that long anything may be the cause...

I had winterized a yamaha once and had trouble firing it and getting it to run. Turns out mice had collected my dogs food and built a nest in the exhaust. When I finally got it to breathe and fire i held the throttle wide open and shot dog food out shotgun style!