Mercury - Air Injector Assembly OptiMax TwoStroke Series Marine-Grade Precision 8M6001744. Overview. Every boater knows that an engine only feels as good as the air and fuel it breathes. When your Mercury OptiMax is running right, there's a crispness to the throttle and a smooth surge of power that lets you settle in and enjoy the ride. The Mercury Air Injector Assembly 8M6001744 helps keep that feeling alive. It restores the clean, efficient air delivery these high-performance two-stroke engine