Mercury - Starter Motor Assembly Electric Start System Marine-Grade Construction 8M0033984. Overview. There's a certain kind of confidence that settles in when you turn the key and your outboard fires up without hesitation. It's the kind of moment every boater knows - early mornings with cool air off the water, or those long days when you're running spot to spot and need your engine to wake up instantly. A dependable starter motor becomes something you don't think about, and that's exactly how i