What I was saying is, that demand in general for fan and free air engines has diminished greatly. The power that you get from a same size liquid cooled engine is generally greater in comparison.
That's not to say that there are applications where the air cooled engine is at an advantage when compared to the configuration of the modern liquid cooled engine sled.
One case is the workhorse machines that pull heavy loads and at slow speeds. Example; A sled that pulls a trail groomer.