15021-881-000 Oil Pump Rotor Set - Overview. The 15021-881-000 Oil Pump Rotor Set is a crucial component designed for the oil pump system in Honda marine engines. It serves the essential function of circulating lubricating oil throughout the engine, ensuring all moving parts are properly lubricated to reduce wear and maintain optimal engine operation. Engineered to meet exact factory specifications, this OEM rotor set ensures seamless integration with existing parts, maintaining optimal performa