Left bike on prime now it won't start

[supplebones]

I recently bought an 08 GS500F with about 3k miles on it.  The bike ran great when I got it, I rode it for about a week before accidentally leaving it on prime over the weekend. I found the bike on Monday sitting above a puddle of gas and unable to start. I ended up pulling off the air box and the carb. The airbox was full of gas so I replaced the air filter and I adjusted the float height on the carb and replaced the float bowl gaskets since I already had it taken apart. I got the bike back together but now the bike won't start unless the throttle is opened, and dies immediately once its closed. I played with the idle screw a bit but I'm pretty confident that's not the issue. Any suggestions on what I might have screwed up?

[Meukowi]

change the oil!! might be some low viscosity oil there

[chris900f]

change the oil!! might be some low viscosity oil there

Good point!

Also the plugs probably got soaked down, "dies unless you hold the throttle open" often means you are only running on one cylinder.

[mr72]

Probably blowing fuel and oil mix past the rings from the crankcase into the cylinders. Change the oil, see how it goes.