There's a really good chance it was just a bit of crud keeping the valve from sealing the fuel inlet when the float bowls rise, a good shot of carb cleaner will remove that. Rare but possible that a float is leaky and has fuel in it keeping it from closing the valve, you'll feel the extra weight if that's true. Also not common but possible the float needle itself is bad and won't seal, you'll see a defined ring at the rubber tip if that's the case, use a flashlight it's hard to see while mounted on the engine. But my money is on crud, give it a good blast. And if you can find a can of Seafoam Deep Creep give both bowls a liberal spray and go ride.
