Mercury Outboard Water Pump Upper Housings

The outdrive resembles the bottom half of an outboard motor and is composed of two sub-units: an upper containing a driveshaft connected through the transom to an engine which transmits power to a 90-degree-angle gearbox; and the lower containing a vertical driveshaft receiving power from the upper unit gearbox.

The top half of the engine contains the outboard powerhead, which is made up of several different components. The mid-section refers to the middle part of the engine, and the outboard lower unit is located below. There are three major sections of an outboard motor which are the powerhead, the midsection and the lower unit. The midsection includes the exhaust housing, the lower unit includes the gearbox and has the anti-ventilation plate, water intake propeller and skeg.