Abstract: The invention is a decompression kit for large bore and/or high compression internal combustion engines. Specifically designed for engines such as the “Harley-Davidson®” “V-Twin®” or the “Sportster®” models, the invention vents high cylinder pressure and reduces the associated high starter torque required to turn the crankshaft when starting the engine, this in turn reduces the cranking amperage necessary to start the engine resulting in longer starter and battery life. A modified spark plug, steel tubing, and decompression valves are the main components of the invention. Cylinder pressure during the compression stroke is vented through the spark plug, tubing, and the decompression valve to make starting the engine easy.