Mercury - Quicksilver Fuel Injector For 135-150HP DFI OptiMax Outboards 804527. Overview. When your outboard starts running rough or losing power, it could be time for a new injector. The Mercury Marine 804527 Quicksilver Fuel Injector is designed specifically for Mercury 135-150HP DFI OptiMax 2-Stroke outboards, ensuring clean, consistent fuel delivery to every cylinder. It's a precision-built, factory-tested component that keeps your engine running strong, smooth, and efficient - just like it