Yamaha - Gear Pump Assembly Engine Lubrication Component 6C5-43830-09-00. Overview. Oil flow is one thing you never want to gamble with on an outboard. This gear pump is what keeps everything inside the engine lubricated and protected while it's running. When they start to wear out, you'll notice changes in noise, heat, or pressure before anything else. I've seen engines stay healthy for years just because this part was doing its job right.. Key Features. • Consistent Oil Pressure - Maintains steady lubrication throughout the engine.. • Precision Gear Operation - Uses internal gears to deliver reliable oil flow under load.. • OEM Fit Accuracy - Matches Yamaha factory specs for proper installation and alignment.. • Heavy Duty Construction - Built to handle heat, pressure, and continuous operation.. Engine & Boat Compatibility. Verify compatibility with your specific Yamaha outboard model and part number before installation.. FAQs. Q1: What are signs this gear pump is failing?A: Low oil