I bought a cbr 600 F3 yesterday and it fired up normally, ran well and idled perfectly. Today I tried starting it, push-starting, cleaning the carbs, checked all the spark plugs. It's getting fuel, has compression and spark but it won't start. It just keeps flooding the cylinders, ty for all the help in advance

 

It can't have air, fuel and spark and not run - that's not possible. Are you sure you checked the basics - like gas tap on, ignition on, no immobilizer etc?

 

Flooding cylinders sounds like carb's float-valves aren't working. Letting float-levels get too high and putting too much petrol into engine.