MJM Yachts LLC 34z Downeast, Owner'S Manual

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CHAPTER 8 RAW WATER SYSTEM
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8.1 GENERAL
Raw water (seawater) is used to cool the engine and the generator. It is also used in the saltwater
washdown and air-conditioning options. Wherever raw water enters the boat, it does so through a
seacock, which is a valved thru-hull penetration. [See Figure 14.6]
8.2
ENGINE RAW WATER
The engine and generator (if fitted) use separate seacocks and strainers. Before using the engine
or the generator, make sure its seacock is in the INTAKE position. While you are checking this,
visually inspect the strainer to insure that it is not fouled.
Using an engine with restricted raw
water flow can cause over-heating and damage to the engine. When you start an engine, it is
advisable to check the exhaust as it exits the boat to make sure water is being mixed into the
exhaust gas. You should see a surge of water every few seconds. (It make take more than a few
seconds for the first surge.)
8.3
ADDITIONAL RAW WATER USES
In addition to the engine, other options may use raw water supplies. These include the generator,
air-conditioning, and saltwater washdowns. Each of these will have a seacock and a strainer that
need to be open and clear for the proper operation of equipment.
Note: the engine ignition panel is equipped with a raw water discharge warning light (labeled
“exhaust”) that will illuminate when the flow of raw water becomes too small for the engine.