Smart boaters choose genuine OEM. MERCURY part 89540 provides factory engineering designed for your exact engine — exactly what your engine was designed around. Protect your marine investment with genuine MERCURY factory parts. Aftermarket parts often fail when you need them most. Aftermarket components may cost less upfront, but they compromise on materials and precision. OEM engineering ensures exact tolerances and marine-grade construction that outlasts cheap alternatives — preventing premature failure and saving money over the long haul. Choose MERCURY part 89540 and choose quality that lasts. Reliability you can trust. More time enjoying your boat, less time and money on repairs. Over 40 years of marine expertise confirms what smart boaters already know: OEM parts are worth every penny. FITS: Model Compatibility: It is found in models including 20 HP (2-cylinder) and 25 HP (2-cylinder) outboards, specifically those with serial numbers ranging from 6443973 and above (e.g., 6443973 THRU 0B238463) STAY OUT ON THE WATER LONGER WITH GENUINE OEM PARTS FROM US BOATWORKS. Over 2 million parts in stock including NLA and hard-to-find parts. Can’t find what you’re looking for? Call or text us: 913-342-0011