Evinrude’s previous three horse ( the 48 Sportwin – Irgie’s "outboard of the future") had an almost indestructible cast tank which increased the weight. So in order so save weight, they used stamped aluminum lower covers which bent easily and became difficult to install. Many covers were lost. Some experiments were tried using weight saving magnesium. ( Some of the Porsche race cars had magnesium transmissions. ) I got to play with some of the scraps. They made excellent flairs. (This came to a screeching halt when the back porch caught fire.) So the stamped aluminum gas tanks made the outboards lighter, but more vulnerable to abuse. . . . . 😀
