This 10cc (.60ci) tether boat engine was designed and built by Ed Kalfus, of MI, in the 1950s. The engine is 5”-long, 3.5”-wide, 5.5”-high, and weighs 1 lb. 10 oz. The engine is one of many custom engines built by Ed Kalfus between 1931 and the late 50s. The small brass carburetor in the back is set to run the engine at low speed for startup and last-minute checks on the adjustments and operation. It requires the throttle of the front carburetor to be completely closed during this process. Once everything is checked and tuned for the race Ed would simply open the throttle on the front carburetor to full open and release the boat. It required the front carburetor to be set to compensate for the additional intake of the rear carburetor while running at full throttle.