If you can see fuel spitting out, then you do not have the air box installed. These engines are reed valve engines. Because reeds do not close instantaneously and because there is a single carb for each cylinder, there is always a little fuel/oil mix blowing out the carbs. This is because of the reeds and the pulsing nature of the airflow. The air box collects this spit-back and recycles it through a fitting and tube on the bottom back into the manifold.
If you have fuel dripping from the airbox, then the fittings or hose are clogged.
