The first fuel system using a reed valve was also incorporated into the new engines and they were ready to be introduced in 1940 as the Mercury range after the messenger of the Roman Gods. Immediately after the war the production of outboards restarted and grew China Tilting Disc Check Valves Manufacturers as boating started catching on as a pastime. When he bought the company he also got 300 outboard motors that were regarded as rejects as they had defects and wouldnt run. His original plan was to design and manufacture magnetic separators for use within the dairy industry. Carl decided at that point in 1939 to improve the design of the outboard motor and manufacture them instead of dairy machinery. Two months was all it took to have a prototype designed and built and a practical test of which chainsaw could cut through a 24inch log would determine if the army or Carl would get the contract.

Just as the company started to really well the Second World War stopped all production of outboards and Carl pushed to win a government contract to supply chainsaws for the army.

Carl worked on the design of his own brand of motors taking into account all the things that were wrong and unreliable with the outboards that were already available at that time. His machine beat the army one by 35 seconds taking only 17 seconds to cut the log and won the contract and this ensured the companys survival through the war. But when the mail order firm called to order more of the engines as they proved popular and reliable and a second company showed interest in the motors and they requested another engine an alternate-firing twin cylinder model to be designed and built for them he had to revise his plans.

He bought a failing Cedarburg outboard engine company with financial foot valve backing from his father with the intention of using the premises to produce his magnetic separators. Carl had seen the outboards as a way to get some money quickly into his business which was called the Kiekhaefer Corporation at that time. After looking at them he put to work along with his small workforce and repaired all of them and contacted the original buyer who had rejected them.

Carl Kiekhaefer had never planned to have anything to do with outboard motors when he graduated as an engineer from college.

Today Mercury produces a range of top class outboard motors up to 300 horsepower along with inboards and jet drives. The army had been trying to develop a more portable version to replace the ones currently used and Carl was sure he could beat their design. The order had been with a mail order firm and they agreed to take the engines from Carl now they were working and sell them. Being an engineer and needing money Carl decided to examine the engines and see if they could be repaired and sold.

He developed a water pump rotor that withstood dealing with silt and vegetation by making parts of it from rubber and a housing to protect the drive shaft and exhaust. His plan was to introduce his first range of engines so that they would be superior in power and reliability than anything that was currently available. The New York boat show in 1940 was where he presented his outboard motors to the public and dealers for the first time and took 16,000 orders for engines at this one show