The engine was designed for the 1/2A Texaco RC duration competition. The engine has an additional fin on the larger glow plug which dissipates heat better allowing the engine to swing a larger propeller. i.e. 7 or 8 inches. This engine has a red 8cc fuel tank and a black crankcase. Original 1989 engines did not come out with 5 fin glow plug. The 5-fin glow plug came later in the 1992 Catalog. This engine also has the smaller 0.062" venturi opening of the Babe-bee to provide a longer engine run.