Mercury - Starter Motor EFI FourStroke Series Marine-Grade Assembly 879345T77. Overview. Every boater knows that moment right before you start the engine-the slight pause, the quiet hope, and the familiar twist of the key. When your starter motor is dependable, that moment turns into a smooth, confident roar that sets the tone for your entire day on the water. The Mercury 879345T77 Starter Motor is built for exactly that feeling. It's the same starter your outboard was born with, designed to cra