Advance MA142 Marine Gearbox The Advance MA142 series gearbox has the functions of deceleration, reverse and forward clutch, and withstands propeller thrust. This series of gearboxes are mechanically controlled and feature small size and light weight. Marine Gearbox Model Advance MA142 Input Speed 1500-2500 Reduction Ratio(i) 1.97   2.52   3.03 Trans …