About Sierra Sierra is dedicated to protecting you and your investment. For 50 years Sierra, one of the most trusted names in the marine industry, has proudly been offering high quality engine and drive parts. Their products meet or exceed the original equipment part it replaces and are engineered to meet today's high horsepower engine demands while withstanding the harsh marine environment. Sierra. Sierra warrants its products to be free of defects in workmanship and materials for the useful life of the product. Sierra will repair or replace the defective product free of Charge. conditions and limitations. You can view sierra..