The Shovelhead engine was created as the previous Panhead engine was becoming obsolete, with many Harley-Davidson owners demanding more power to compete with the more modern motorcycles. Throughout the Shovelhead’s run, the engine had many different changes made to it to improve power, cooling and oil consumption. The engines had only 10 fins for cooling, which caused them to run hot. Another problem was that oil would pool in the cylinder heads, causing it to leak into the valves and burn oil. Another problem was that oil would pool in the crankcase rather than being pumped, causing the engine to overheat and seriously harm performance. Oil leakage and consumption became such a problem with the bikes, many owners reported losing as much as a quart of oil every 500 miles. The excessive overheating in the motors also caused serious problems, which frequently led to failure. With a lack of oil and excessive heat, the valves were prone to sticking and destroying the top end. Numerous Harley technicians even stated that without necessary top-end modifications, the motors would often last only between 500 and 5,000 miles. With Harley-Davidson trying to fix the engine rather than research and develop, they fell far behind the competition of the cheaper and more reliable Japanese bikes taking control over the market.