Fewer things evoke the image of the American open road more than a Harley-Davidson (HD) motorcycle. First produced in 1957, the HD Sportster still boasts classic styling. However, much has changed over the years with regard to engine specifications. For those wishing to purchase a 1975 HD Sportster, it is important to know the engine specs so you know what you are purchasing and what you need if repairs are necessary.
Type of Engine
The 1975 Harley-Davidson Sportster engine is a V2, four-stroke engine. V2 refers to the fact that the engine operates with two pistons. Four-stroke is a type of engine that goes through four “strokes” on each rotation. Two-stroke engines merely go around in circles, while four-stroke engines provide both compression and exhaust on each rotation. Four-stroke engines have longer lives than two-stroke engines. They are also more fuel efficient and burn less oil, saving you money in the long run. The engine in the bike uses an overhead valve fuel control system. This system is cooled with air.
Displacement and Compression
Displacement refers to how much space an individual piston travels through for a single turn of the camshaft. The larger the displacement, the more power your engine has. The 1975 HD Sportster engine has a displacement of 997 cm or over 60 cubic inches. A related specification is compression of your Harley’s fuel when the piston reaches the highest point of its movement. The compression ratio of the 1975 Sportster is 9-to-1.
The Harley-Davidson Sportster uses a chain transmission system. The chain drive is the most efficient means of moving power from the engine to the wheel, in comparison to less efficient systems such as belts and shafts. Additionally, the bike has a 4-speed engine.
Speed and Power
The engine of the Harley-Davidson Sportster 1975 edition boasts over 50 horsepower when the engine is running at 6,000 revolutions per minute. You can get the bike up to 180 mph, but should always drive within posted speed limits.