Beta Marine Beta 10 Operator's Maintenance Manual page 13

IMPORTANT
Removal of the pressure cap when
the engine is hot can cause severe
injury from scalding hot water under
pressure. Always allow the engine to
cool and then use a large cloth when
turning the cap anti-clockwise to the
stop. This allows the pressure to be
released. Press firmly down on the
cap and continue to turn
anticlockwise to release the cap.
YACHTS AND LAUNCHES
WITH HEAT EXCHANGER
COOLING
It is essential that a 33% to 50%
anti-freeze/water mixture is used.
This not only stops freezing up in
winter, but it prevents overheating
and corrosion.
The warranty is invalid unless the
correct ratio is used.
Fig. 2l
coolant level is more than 1 inch
below the base of the filler neck
when the engine has cooled
down.
(j) Run engine on 2/3 full load for
20 minutes, check for leaks and
repeat (i).
(k) Anti-freeze solutions should be
drained off every 2 years and
replaced with a new solution.
CANAL BOATS WITH KEEL
COOLER
A 33% anti-freeze to water mixture is
recommended to give protection
against very cold winter temperature of
minus 15°C. This anti-freeze will also
give the engine internal protection
against corrosion. For keel cooled
engines the total system capacity must
be taken into consideration, ie engine
volume plus skin tank/keel cooler
volume.
(i) Repeat (h) if
11
Fig. 2m
Note: When draining fresh water
system, ensure the engine has cooled
sufficiently to prevent scalding from
hot pressurised water. Prior to
draining a cold engine, remove the
filler cap from the header tank and
then open the water drain tap. This
allows the water to drain freely from
the system.
Concentration of ethylene should not
exceed 50%.
The anti-freeze in the fresh water
system enables the boiling point of
water to rise to 124°C with a 13 psi
pressure cap fitted. The water
temperature alarm switch will however
be activated at 95° to 100°C. If no
anti-freeze or a very weak solution is
used, then the water temperature
switch may not be activated before
coolant is lost.