21
Freshwater Cooling System
New engines are supplied with the freshwater drained off.
The following instructions must be followed to fill the system.
(a)
Mix up in a clean bucket a solution of 50% anti-freeze/water mix.
(b)
Fill engine with the freshwater/anti-freeze solution through the top of the
header tank with the filler/pressure cap removed.
(c)
Fill the header tank to the top of the filler neck and replace cap. Press down
firmly on filler cap and hand tighten in a clockwise direction.
Note: for keeled cooled engines a larger volume of freshwater/anti-freeze mix is
required depending on the size of the keel cooling tank – refer to the builder.
(d)
Run the engine for 5 minutes on no load (out of gear) and then check the
coolant level. Top up if necessary.
(e)
Check the complete system for leaks, including the Calorifier circuit if fitted.
Note: for keel cooled engines it is very important to bleed all the air out of the
system before the engine is run on load (check the boat builders’ instructions).
(f)
If a Calorifier is fitted care must be taken to see that this is also full of coolant
and all air is expelled. (see Calorifier notes in installation section)
(g)
Run the engine on one third speed for 15 minutes, preferably with the boat tied
up. As the system warms up coolant may be expelled from the overflow pipe
into the bilge. Stop the engine and allow the engine to cool down before
removing the pressure cap and top up the coolant to 25mm below the filler
neck.
Important
Removal of the pressure cap from a hot engine, can cause severe injury from hot
coolant 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.
(h)
Repeat (g) if coolant level is more than 25mm below the base of the filler neck
when the engine has cooled down.
(i)
Run engine on
2
/
3
speed for 20 minutes, check for leaks and repeat (g)
(j)
Anti-freeze solutions should be drained off every 400 hours or 2 years
whichever is sooner, and replaced with a new solution, dependant on the type
of Antifreeze used.
Engine water filler
cap, integrated into
the header tank.
