Installation manual
COOLING
SYSTEM
RAW
WATER
PUMP
The
raw
water
pump
is
a
self-priming,
rotary
pump
with
a
non-ferrous
housing
and
a
neoprene
impeller.
The
impeller
has
flexible
vanes
which
wipe
against
a
curved
cam
plate
within
the
impeller
housing,
producing
the
pumping
action.
On
no
account
should
this
pump
be
run
dry
as
water
acts
as
a
lubricant
for
the
impeller.
There
should
always
be
a
spare
impeller
and
impeller
cover
gasket
(an
impeller
kit)
onboard.
Raw
water
pump
impeller
failures
occur
when
lubricant
(raw
water)
is
not
present
during
engine
operation.
Such
failures
are
not
warrantable
and
operators
are
cautioned
to
make
sure
raw
water
flow
is
present
at
start-up.
The
neoprene
impeller
has
a limited
lifetime
and
must
be
inspected
regularly.
NOTE:
S.hould
a
failure
occur
with
the
pump's
internal
parts
(seals
and
bearings),
it
may
be
more
cost
effective
to
purchase
a
new
pump
and
rebuild
the
original
pump
as
a
spare.
Inspecting/Changlng
the
Raw
Water
Pump
Impeller
Close
the
raw
water
intake
valve.
Remove
the
pump
cover
and,
with
the
aid
of
two
small
screwdrivers,
carefully
pry
the
impeller
out
of
the
pump.
Install
the
new
impeller
and
gasket.
Move
the
blades
to
conform
to
the
curved
cam
plate
and
push
the
impeller
into
the
pump's
housing.
When
assembling,
apply
a
thin
coating
of
lubricant
to
the
impeller
and
gasket.
Open
the
raw
water
intake
valve.
NOTE:
Never
allow
the
pump
to
run
dry.
Even
a
short
period
of
dry
running
may
destroy
the
impeller.
RAW
WATER
PUMP
RAW
WATER
INTAKE
A
flush-type
though-hull
fitting
is
recommended
for
the
raw
water
intake.
It
should
be
located
on
the
boat's
hull
where
it
will
be
below
the
waterline
during
all
angles
of
the
boat's
operation.
See
Westerbeke's
INSTAlL4.TION
MANUALfor
MARINE
ENGINES
and
GENERATORS
for
complete
installation
guidelines.
A
WARNING:
Do
not
use
a
scoop-type
through-hull
fitting
for
supplying
raw
water
to
this
engine.
A
scoop-
type
raw
water
inlet
can
develop
substantial
pressure
and
force
water
past
the
raw
water
pump.
flooding
the
exhaust
system
and
allowing
the
water
to
enter
the
engine's
cylinder.
Damage
caused
by
raw
water
entry
into
the
engine's
cylinder
ria
the
exhaust
system
is
not
covered
by
Westerbeke's
wananty.
Flooding
of
the
exhaust
system
due
to
water
pressure
can
also
occur
with
a
flush-type
raw
water
intake
on
a
powerboat
that
has
its
bow
up.
This
pressure
can
be
caused
by
the
boat's
decreased
waterline
before
the
boat
reaches
its
final
trim,
or
by
the
angle
of
the
boat
to
the
sea
surface
when
its
is
underway.
RAW
WATER
INTAKE
STRAINER
NOTE:
Always
install
the
strainer
at
or
below
the
waterline
so
the
strainer
will
always
be
self-priming.
A
clean
raw
water
intake
strainer
is
a
vital
component
of
the
engine's
cooling
system.
Include
a
visual
inspection
of
this
strainer
when
making
your
periodic
engine
check.
The
water
in
the
glass
should
be
clear.
Perform
the
following
maintenance
after
every
100
hours
of
operation:
1.
Close
the
raw
water
seacock.
2.
Remove
and
clean
the
strainer
filter.
3.
Clean
the
glass.
4.
Replace
the
sealing
washer
if
necessary.
5.
Reassemble
and
install
the
strainer.
6.
Open
the
seacock.
7.
Run
the
engine
and
check
for
leaks.
NOTE:
Also
follow
the
above
procedure
after
having
run
hard
aground.
If
the
engine
is
indicating
higher
than
normal
operating
tempera-
tures
(i.e
the
alarm
is
sounding),
the
cause
may
be
that
silt,
leaves
or
grass
may
have
been
caught
up
in
the
strainer,
slowing
the
flow
of
raw
water
through
the
cooling
system.
Engines & Generators
22