Flash light time or a dye the you can purchse to put into the fluid. It needs to be pin pointed because a front pump will leak from that area also. Tranny pans will seep and collect from that area throwing you off. I've experienced dipsticks leaking because of the fluid build up upon shut down and they drip from the front. Really need to do some extra detective work so you don't do extra labor chasing the wrong area. Carb? You have to get a bit deeper, those amount of turns won't cause the richness. Jetting? Float level too high? You have some possibilities that need to be double checked.