Mercury - Compressor OptiMax Two-Stroke Series Marine-Grade Construction 8M0133589. Overview. There's a certain peace that settles in when you know your engine is breathing the way it should. You feel it when you push the throttle and the response is instant, clean, and confident. That's the kind of trust boaters grow into over seasons spent running the same back bays, long channels, and open stretches. The Mercury Marine part 8M0133589 compressor delivers that feeling - the steady assurance tha