John, you may have missed it, but I’ll promise you that there is a route from the slinger area, down through the reed plate, to the intake manifold. Manifold vacuum is what sucks the oil down to the manifold to be recycled. The route through the reed plate includes the holes at the top of the gaskets, shown in the picture.
You are correct that a passage such as that could cause a lean condition. But they thought of that a long time ago, and there is a small orifice somewhere along the way to control the amount of airflow.
Yes, the slinger is a press fit on the shaft and rotates with the shaft, and there is a space below it. Any attempts to modify the design would—–well modify the way it works. It is a well proven design, used on a few trainloads of small OMC motors. No, it is not 100% absolutely effective. A small bit of oil may get through and onto the points. But by then, you would be going into it anyway for a routine ignition tune-up, wouldn’t you?
