Yanmar 2GM20

The engine is equipped with a starting motor (D.C. 12V, 1 kW), and an alternator to provide electricity and charge onboard batteries (12V, 55A).

The exit of cooling water from the exhaust into the sea (typically at the aft of the boat) should be checked at that time.

The impeller of the seawater pump can suffer from wear and tear, especially when run dry for some period of time, in which case it has to be replaced to avoid loss in the flow of cooling seawater, a potential source of engine overheating.

In extremes, it is possible for the rubber exhaust hose to catch fire, the plastic silencer to melt and the head-gasket to fail.

The solution is to have a large basket-type water strainer and overheat alarms (standard on most Yanmar engines) The seawater pump is rotated by a short belt linked to the crankshaft.

The water inside diesel fuel can lead to rusting of the internals of the engine, as well as lubrication problems.

Every time a filter is disassembled or changed, it will be necessary to bleed it so as to remove excess air, again by opening the top vent so as to let diesel chase all the air (diesel fills up the filter either through gravity -usually the case for the primary filter- or with the help of the fuel lift pump -usually the case for the engine fuel filter-) and diesel starts to gush out.