You need to clean the entire area well with either alcohol or simple green, rinse with low pressure water...turn her on or go for a ride to heat her up good and well. Carefully look over the entire engine top to bottom, front to rear for fresh oil. Look at rocker covers, push rod seals at top and bottom, rear cylinder base gasket, the area where the wires come through the left case cover for the stator, the grummet can wear. These are the most common areas where leaks pop up.