'85 VF500F Won't Start/ Engine Flood - Carb Problem?

Hey guys, I picked up my 1985 VF500F about a month and a half ago but finally got down to business the past few weekends. It started when I bought it, but there was an obvious fuel leak. We took the carbs off and found an o-ring with a nice chunk taken out of it, so we replaced that, and it fixed the fuel line. Did a brief cleaning of the carbs and threw 'em back in. Now with the fuel leak fixed, the bike won't start. After trying to turn it for awhile, the fuel never shut off, the carbs overflowed through the breather tubes and the engine flooded.

I haven't checked the spark plugs yet, that's the next step, but I don't think it should have flooded that much; shouldn't the carbs have a cut off (like the float/needle)? I pulled the carbs off today and took the float bowls off to inspect. All the floats move freely and there were no glaring flaws (but maybe something minor, my carb knowledge doesn't extend much farther than I can throw them). One of the floats seemed to have more travel than the rest, and the float seemed to hit the housing at the top, while the others felt like the valve bottomed out first. Anyone have any ideas? Am I even looking in the right place?