Johnrudes had a 12 year headstart and more was produced. Also was stangled during war time....
"Observing the success of his two major clients, Kiekhaefer decided it was time to market his own line of outboards, and so, the “Mercury” brand was born.
Unfortunately, shortly after its introduction, World War II broke out. The United States was now embroiled in a battle with Germany, Italy and Japan, and as a result, stiff government restrictions were imposed on raw materials — the most important of which was aluminum, the primary material used in producing outboard motors.
Aluminum was also critical to aircraft production, which became an immediate priority. Although Kiekhaefer petitioned the State Department to lift the restrictions, his appeals were denied. The company’s future was in peril. Meanwhile, Evinrude (Kiekhaefer’s chief rival) had won its petition and was granted access to ample stocks of aluminum. That was salt in the wound for Kiekhaefer.
Eventually salvation came in the way of government contracts. Small businesses across the country were enlisted to build machinery and arms for various branches of the military. Mercury’s role was to produce small engines for chainsaws, generators and drone aircraft. Interestingly, the drone engines were constructed from the same power-heads used to build outboards."