I would say 1947 or ’48. At the end of the war Evinrude was working on a contract for over 10,000 Storm Boat Motors for the invasion of Japan. When Truman authorized the dropping of the two Atomic bombs we had, Japan quickly surrendered. The contract was canceled leaving Evinrude with a vast supply of heavy duty gear cases. Those wanting more speed cut off the "wings" to reduce drag. On the next production run (’47 or 8) the "wings" were elimanated. Dad had modified a heavy duty casting Clyde Weisman supplied for his Big Four. The factory liked it and modified it some more, rounding the knife edge dad had put on the front of the gear case. They put it on all the 1949 Speeditwin, Speedifour and Big Four models.
