Installation manual
ENGINE 
ADJUSTMENTS 
NOTE: 
WESTERBEKE 
recommends 
that the following engine 
adjust-
ments 
be 
pe/formed 
by 
a competent engine 
mechanic. 
The 
information 
below 
is 
provided 
to 
assist 
the 
mechanic. 
TESTING 
OIL 
PRESSURE 
To 
test 
the 
oil 
pressure, 
remove 
the 
oil pressure sender, 
then 
install a mechanical 
oil 
pressure gauge in it's place. After 
warming 
up 
the 
engine, 
set the engine speed at idle and 
read 
. 
the oil pressure 
gauge. 
. 
OIL 
PRESSURE 
WILL 
RANGE 
BETWEEN 
50 
AND 
55PSI 
AT 
1800 
RPM 
LOW 
OIL 
PRESSURE 
, The specific safe 
minimum 
oil pressure 
is 
5 -
10 
psi. A 
grad-
ualloss of oil 
pressure 
usually indicates worn bearings. For 
additional information on low 
oil 
pressure readings, see 
the 
ENGINE  chart. 
OIL 
GALLERY 
MECHANICAL 
OIL 
PRESSURE 
GAUGE 
DlL 
GALLEIiY 
ENGINE 
COMPRESSION 
Check tile compression pressure. 
To 
do 
this warm the engine, 
remove all fuel injectors, or glow plugs, disconnect 
the 
fuel 
shut-off solenoid 
wire, 
and 
install a compression adapter in 
the injector hole or 
glow 
plug hole. Connect a compression 
tester on the adapter 
'and 
crank the engine with 
tl10 
starter 
motor until the pressure reaches a maximum value. Repeat 
this 
process for 
each 
cylinder. Look 
for 
cylinders with 
dramaticaliy (at least 
20%) lower compression than 
the 
average of 
the 
others. 
Compression pressure should not differ 
by 
more than 
35.5 
psi 
(2.5 
kg/cm'). at 280 rpm. 
If 
a weak cylinder 
is 
flaaked 
by 
healthy cylinder, the problem 
is 
either valve 
or 
piston related. Check the valve clearances 
for the weak 
cylinder, 
adjust 
as 
needed and test again. 
If 
the 
cylinder is still 
low, 
apply 
a small amount 
of 
oil into 
the 
cylinder to 
seal 
the 
rings and repeat 
the 
test. 
If 
compression 
comes up -
the 
rings 
are 
faulty. 
Abnonnally high readings 
:on 
all cylinders indicates 
heavy 
carbon accumulations, 
Ii 
condition that might be 
accompanied 
by 
high 
pressures 
and 
noise. 
COMPRESSION 
TESTER 
ADAPTER", . 
.f-
.' 
TESTING 
ENGINE· 
"" 
. 
i""",,'". 
COMPRESSION 
""'~~INJECTOR 
DR 
'.. 
~ 
. 
GLOW 
PLUG 
HOLE 
. 
COMPRESSION 
PRESSURE 
AT 
250 
RPM 
626 
psi 
-
44 
Kgf!crtf 
-4.32 
Mpa 
ALLOWABLE 
LIMIT 
AT 
250 
RPM 
472 
psi 
-33.2 
Kgf!crtf 
-3.26 
Mpa 
NOTE: 
In 
case 
of 
severe vibrations and detonation 
noise, 
the 
cause 
may be fuel injector 
problems, 
see 
FUEL 
INJECTORS. Poor fuel quality, contaminates and loss 
of 
positive fuel pressure 
to 
the injection 
pump 
will 
result· 
in 
injector faults. 
When re-installing the 
glow 
plugs 
use 
anti-seize compound, 
DRIVE 
BELT 
ADJUSTMENT 
Excessive drive belt tension can cause rapid wear of the 
belt 
and reduce the service life 
of 
the fresh water pump's 
bearing. 
A slack belt or the presence 
of 
oil 
on 
the 
belt can cause belt 
slipping, resulting in high operating temperatures. 
The drive belt is 
·properly 
adjusted 
if 
the 
belt can be 
deflected 
no 
less than 
3/8 
inch 
(IOmm) 
and no more than 
112 
inch (12mm) 
as 
the 
belt is depressed with the thumb 
at 
the 
mfdpoint between the 
two 
pulleys 
on 
the 
longest span 
of 
the 
. 
belt. A spare belt or belts should 
always 
be carried on 
board. 
A 
WARNING: 
Never 
attempt 
to 
check 
or 
adjust 
the 
drive 
belt's 
tenSion 
while 
the 
engine 
is 
in 
operation. 
Adjusting 
Belt 
Tension 
1.  Loosen 
the 
alternator pivot bolt. 
2.  Loosen the alternator adjusting bolt. 
3.  With the altemator loose, swing it outward until the 
drive 
belt is tensioned correctly. 
4.  Tighten both bolts. 
5.  Check the tension again after 
the 
engine has been in 
operation. 
Englne_s 
&.Generators 
ADJUSTING 
BOLT 
26 










