Information about the template:
In 1952, the predecessors of the Sportster, the Model K Sport and Sport Solo motorcycles, were introduced. These K, KK, KH and KHK models from 1952 to 1956 had a side valve ("flat head") engine. This is developed from the earlier 45W model, but with a revised engine and new 4-speed transmission contained in the same castings as the Sportster would become. The connecting rods would be inherited by the Sportster along with many other design elements and dimensions.
Model K and KK were produced in 1952-1953. The side valve engines had a volume of 750 cc.