OPERATING MANUAL FOR BUKH DV24ME ENGINES
009W0825-R02
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Freshwater Cooling
When using freshwater cooling it will be possible to reach a higher operating temperature of 70-95°C which will prolong the
life of the engine. This cooling system is recommended for engines operating for more than 500 hours a year. A pump
circulates the freshwater in a closed system.
This circulation pump is fitted on the front end of the engine and is driven by a V-belt.
The freshwater circulates through the cooling jackets of the engine and through the heat exchanger fitted on the water
cooled exhaust manifold.
The freshwater is cooled in the heat exchanger by seawater which is pumped through by a big impeller pump like the one
used for direct seawater cooling.
Too high cooling temperature will cause the blue lamp in the control panel to light up and the acoustic alarm to function.
See “Winter storage of the engine” page 11.
Frost precautions
To avoid damaging the engine, drain the cooling water during frosty periods.
To protect the engine against damage caused by frost, proceed as follows:
1. Turn off the cock on the cooling water inlet skin fitting.
2. Drain the cooling water off the engine by removing the plug above the lubricating oil filter on starboard side and under
the exhaust manifold, respectively.
3. Clean up the drain holes with a nail, a steel wire or the like, so that any remaining water may drain out.
4. Start the engine and let it run for 30 seconds to remove all the water from engine and exhaust manifold. Running for
that short time will cause no damage to the impeller of the pump.
On engines fitted with heat exchanger cooling it is recommended to use a mixture of
min. 30% antifreeze liquid and 70%
water
and
max. 50% antifreeze and 50% water
as protection against corrosion and to secure the cooling water freezing
temperature to min. minus 15° Celsius or lower if required from climate conditions.
However
please also note when doing service on the boat
that the mix of water and antifreeze can get aggressive and
start corrosion. If corrosion is found in the cooling system it can be caused by one of two conditions:
1. The anti corrosion additives in the anti freezing liquid are exhausted and have evaporated.
2. Oxidation due to incoming air causing an acid which is lowering the PH value.
Therefore and also to keep the anti freezing properties it is recommended to
change the cooling water and antifreeze
every 3 years min.
Please also note the details provided by your supplier of antifreeze liquid normally stated on the can.
Heat exchanger cooling water capacity for DV24 is 4.8 litres.
Drain the raw water from the heat exchanger cooled engines by taking off the seawater pump cover.
Electrical System
The engine is equipped with a 12 volt electrical system consisting of a starter motor and an alternator, the max. charging
current of which is 50 Amp.
Electrical wiring diagram for the engine with control and instrument panels is shown later in this instruction.
The level of the electrolyte in the battery should be checked every 14 days or every 25 operating hours. The level should be
5-6 mm above the plates, if this is not the case top up as required with destilled or demineralized water.
The battery must never be isolated from the alternator, when the engine is running.
Warning! It is not allowed to connect additional equipment to the wiring system on the engine. Possible additional
equipment has to be connected directly to the terminals of the battery.
NOTE!
The starter must not be operated for more than 10 sec. If further operation is necessary, a pause of at least half a minute
before starting attempt is repeated.
Marine Gear
The engine is equipped with a reverse-reduction gear. The reduction is 3:1 for AHEAD
and 2.36:1 for REVERSE.
The marine gear will need no other attendance than regular change of oil. This to be
carried out after 25 hours of operation, and then every 150 hours or once a year. See
oil quality "Technical data" .
The oil change is carried out by means of the lubricating oil bilge pump.
The oil should be warm when draining.
Refill new oil to the quantity og 1.1 liters through the dipstick hole.
Check oil level on the dipstick.
