Scout Boats 420 LXF, Owner'S Manual

Page: 156 / 202

156
Seasonal Maintenance
14.3 Raw Water System Winterizing
The raw water washdown and seawater supply
pumps and systems must be completely drained
and winterized using the following procedure.
Sea Chest & Sea Water Supply Systems
The sea chest and raw water systems supplied by
the sea chest require the following procedure to
be properly winterized.
Sea Chest and Boat Sea Water Pumps
1. Remove and clean the screens for both sea
strainers on the intake lines for the sea chest.
Reassemble the strainers.
2. Close all pump supply valves on the sea chest
and open both inlet valves.
3. Remove the vent hose from the sea chest and
use compressed air at very low pressure to
blow the water from the sea chest.
4. Remove the drain plugs in both sea strainer
bowls and use compressed in the sea chest to
blow all water from the intake lines and both
sea strainers.
5. Replace the strainer drain plugs and close the
intake valves.
6. Disconnect the inlet and outlet water lines from
the raw water washdown pump at the pump.
Open the nozzle on the cockpit washdown
hose and use very low pressure to blow as
much water from the pressure line and hose
as possible.
7. Open the raw water supply valve on the sea
chest and use compressed air to blow the
water from the raw water pump intake line.
8. Because of the check valve mechanism built
into the raw water washdown pump, blowing
the lines will not remove the water from the
raw water pump. Make sure the inlet and
outlet lines are disconnected from the pump.
Turn the pump on and allow it to pump out
any remaining water....about a cupful.
9. Reconnect the lines to the pump and remove
the lid for the sea chest. Thoroughly clean the
inside of the lid and seal.
10. Fill the sea chest will potable water antifreeze
and reinstall the lid.
11. Connect one end of a five foot length of hose
to the vent fitting on the sea chest and place
the other end in a 5 gallon bucket filled with
potable water antifreeze. Have another five
gallon bucket of antifreeze available to fill the
supply bucket as necessary.
12. Open the raw water pump supply valve and the
nozzles on the washdown hoses. Make sure
the hose connected to the sea chest vent fitting
is at the bottom of the bucket of antifreeze and
activate pump. The pump will create a vacuum
and draw the antifreeze from the bucket into
the sea chest. Add antifreeze to the bucket
as necessary and allow the pump to run until
antifreeze is flowing from the washdown hose
nozzle. Then shut off the pump and close the
hose nozzles and supply valve.
13. Run the other pumps connected to the sea
chest one at a time until the antifreeze solution
is visible at all raw water outlets and discharge
fittings. Be sure antifreeze has flowed through
all of the raw water drain thru-hull fittings.
Generator Raw Water Cooling System
Drain the heat exchanger and raw water supply
and discharge lines for the generator seawater
cooling pump. If the generator muffler is equipped
with a drain plug, remove the plug and drain the
muffler. Reinstall the drain plugs when draining
is complete. The use the following procedure to
fill the generator seawater cooling system with
antifreeze.
1. Make sure the sea chest and raw water system
has been winterized as previously described
in this section.
2. Make sure the bucket and sea chest are full
of antifreeze and open the generator supply
valve. Make sure all other valves on the sea
chest are closed.
3. Start the generator. The generator seawater
cooling pump will draw antifreeze from the sea
chest and pump it through the seawater cool-
ing system. The pump will create a vacuum
and draw the antifreeze from the bucket into
the sea chest.
4. Monitor the exhaust and add antifreeze to the
supply bucket as necessary until antifreeze is
flowing from the exhaust port, then shutdown
the generator and close the supply valve.
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