S&S Cycles manufactures aftermarket engines for Harley-Davidson motorcycles.
S&S Cycles in Wisconsin makes carburetors, performance parts and entire V-Twin engine assemblies for Harley-Davidson and Harley-Davidson-like motorcycles like Big Dog and Ironhorse motorcycles. The engines cost about as much as Harley engines, but they are hand assembled, come with large displacements and have a long-established reputation for craftsmanship. Several very visible marks make them easy to recognize. S&S motors also have unique engine identification numbers which, because S&S manufactures fewer engines, are shorter than Harley engine identification numbers.
1. Walk to the right side of the engine and look at the carburetor. S&S engines come equipped with S&S carburetors. These carburetors have a distinctive, polished-steel, tear-drop-shaped air cover that is stamped with “S&S.”
2. Look at the cylinder heads. S&S engines come with cylinder heads stamped “S&S ” on the right side of the engine. “S&S” is also stamped on the right side of the transmission cover.
3. Illuminate the left side of the motor with a flashlight and examine the federally mandated engine number on the left side of the crankcase at the base of the rear cylinder. Harley-Davidson engines have engine numbers comprised of four letters followed by six numbers. All S&S motors have seven- or eight-character engine codes that begin and end with an asterisk. A typical S&S engine code begins, after the asterisk, with a single letter followed by five digits.