Installation manual
COOLING 
SYSTEM 
THERMOSTAT 
A thennostat, 
located 
near 
the 
manifold 
at 
the 
front 
of 
the 
engine, 
controls 
the 
coolant 
temperature 
as 
the 
coolimt 
continuously 
flows 
through 
the 
closed 
cooling 
circuit. 
When 
the 
engine 
is 
first 
started, 
the 
closed thermostat 
prevents 
coolant 
from 
flowing 
(some 
coolant 
is 
by-passed 
through 
a 
hole 
in 
the 
thermostat 
to 
prevent 
the 
exhaust 
manifold 
from 
overheating). 
As 
the 
engine 
warms 
up, 
the 
thermostat 
gradually 
opens. 
The 
thermostat 
is 
accessible 
and 
can 
be 
. 
checked, 
cleaned, 
·or 
replaced 
easily. 
Carry 
a 
spare 
thermostat 
and 
gasket 
Replacing 
the 
Thermostat 
Remove 
the 
cap 
screws 
and disassemble the 
therrrio~tat 
housing 
as 
shown. 
When 
installing the 
new 
thermostat 
and 
gasket, 
apply 
a thin 
coat 
of sealant 
on 
both 
sides 
of the 
gasket 
before 
pressing 
it into 
place. 
Do 
not 
over-tighten 
the 
cap 
screws. 
Run 
the 
engine 
and 
check 
for 
normal temperatures 
and 
that 
there 
are 
no 
leaks 
at 
the thermostat housing. 
AIR 
BLEED 
P~~~/~~~~;;;;~~~ 
FOR 
PUSHING 
AIR 
FROM 
THE 
COOLING 
SYSTEM 
COOLANT 
TEMPERATURE 
SENDER 
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 
i,ntake 
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 
·shoufd 
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. 
Ciean 
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 temperature 
gauge 
eyer 
shows a higher 
than 
. 
normal 
reading, 
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. 
WASHER 
HI-TACK 
SEALANT 
THERMOSTAT 
ASSEMBLY 
THERMOSTAT 
PART 
NO. 
47571 
FILTER 
BY·PASS 
HOLE 
TYPICAL 
RAW 
WATE:;Riiii~; 
(OWNER 
INSTALLED) 
INCOMING 
RAW 
WATER 
SEACOCK 
-r'li(l" 
~ 
...v 
WESTERBEKE 
Engines· & Generators 
17 
INSPECTAND 
CLEAN 
EVERY 
100 
HOURS 










