Cylinders

• The 1977 GS 550 has a 549 cubic-centimeter (or 33.5 cubic-inch) engine displacement. The engine has four cylinders inline with two valves per cylinder. The valves are controlled by a double overhead cam configuration. The bike is four stroke, which means the pistons take four strokes to complete an engine cycle.
  
  

Bore, Stroke and Compression Ratio

• The bore and stroke of the cylinders, where bore is the diameter of the engine cylinder opening, and stroke is the total distance the piston travels up and down, is 2.2 inches by 2.2 inches.
  
  The compression ratio of the 1977 GS 550 engine is 8.6 to 1. This is the ratio of the volume between the piston and cylinder head before and after a compression stroke.
  
  

Fuel and Power

• The fuel induction system uses four VM22SS Mikuni carburetors and the engine is air-cooled. The 1977 GS 550 produces 49 horsepower and has a top speed of 114.3 mph. The bike can cover a quarter mile from standing in 13.7 seconds.