there shouldnt be fuel coming out of the case. sometimes what does happen is if you leave the feul petcock on the PRI position it will dump feul into the case and contaminate the oil. this causes the oil level to rise which can cause the oil to blow out the breather in the airbox. the oil will smell badly of gas. smell it and if it does change the oil and keep the petcock off of PRI, unless your filling the carbs, that might clear up the problem. im not 100% sure if thats your problem, but its not expensive and worth a shot. You have to be carefull about that happening, because if the oil is thinned too much by gas it loses its viscosity and your engine may very well seize due to lack of lubrication.