Installation manual
ENGINE
ADJUSTMENTS
NOTE:
WESTERBEKE
recommends
that
the
following
engine
adjustments
be
performed
by
a
competent
engine
mechanic.
The
information
below
is
provided
to
assist
the
mechanic.
TIGHTENING
THE
CYLINDER
HEAD
After
the
initial
break-in
period
(approximately
50
hours),
retorque
the
cylinder
head
nuts.
Do
this
when
the
engine
is
cold.
1.
Remove
the
cylinder head cover and gasket.
2.
Retighten the four cylinder head
nuts
in
an
X-pattern
sequence
as
shown
in
the illustration. Start
with
any
nut.
Before applying the torque to a
nut,
loosen it
114
to
112
a
tum, then apply the
torque.
See TORQUE
SPECIFICATIONS
for
the proper
torque.
3. Reinstall the cylinder head cover
and
gasket. Insert
new
plastic washers under the two
nuts
and tighten
to
the
specified torque.
VALVE
CLEARANCE
ADJUSTMENT
Check
the
valve
clearances
after
the
first
50
hours
of
operation
and
every
600
hours
thereafter.
NOTE:
Tighten
the
cylinder
head
bolts
to
their
specified
torque
before
adjusting
the
valve
clearances
(see
TIGlffENING
THE
CYUNDER
HEAD).
Adjust
the
valve
clearances
when
the
engine
is
cold.
The
clearance
is
0.2
mm
(0.008
in.)
for
both
intake
and
exhaust
valves.
1.
Remove the cylinder
head.
2.
Check
to
make
sure
the
automatic decompression
device
is
in
its
normal
operating position,
i.e.
not
activated
(see illustration).
POINTER
'---l-'H--
AUTOMATIC
DECOMPRESSION
DEVICE
IN
THE
NORMAL
OPERATING
POSITION
~
~
="~JJ=======
3. Set the piston at
the
TDC
of the compression
stroke.
4.
Loosen the locknuts
on
the valve setting
screws
(see
illustration).
5.
For
each
valve, insert a
0.2
mm
(0.008
in.)
feeler
gauge
between
the
valve stem
and
the
rocker
arm,
and
adjust
the
clearance until a slight
drag
is
felt
on
the gauge
when
it
is
pulled
out.
6.
Tighten
the
locknut while holding
the
setting
screw
with
a screwdriver.
7.
Recheck
the clearance.
ENGINE
COMPRESSION
TEST
To
check
the
engine's
compression
pressure,
warm
up
the
engine,
shut
off
the
raw
water
through-hull,
remove
the
fuel
injector,
and
install
a
compression
adapter
in
the
injector
hole.
Connect
a
com-
pression
tester
on
the
adapter
and
crank
the
engine
with
the
starter
motor
until
the
pressure
reaches
a
maximum
value.
Compression pressure
at
350 rpm:
Minimum: 435.0 psi (30.6 kg/cm
2
)
Standard: 478.5 psi (33.6 kg/cm
2
)
ADAPTER
~INJECTOR
HOLE
If
the
pressure
is
weak,
the
problem
is
either
valve-
or
piston-
related.
Check
the
valve
clearance,
adjust
as
needed,
and
test
again.
If
the
compression
is
still
low,
apply
a
small
amount
of
oil
into
the
cylinder
to
seal
the
rings,
and
repeat
the
test.
If
the
compression
comes
up,
the
rings
are
faulty.
An
abnormally
high
reading
indicates
heavy
carbon
accumulation,
a
condition
that
might
be
accompanied
by
high
pressure
and
noise.
NOTE:
In
case
of
severe
vibrations
and
detonation
noise,
have
the
injector
checked
and
overlw.uled
by
an
authorized
fuel
injection
service
center.
Poor
fuel
quality,
contaminants
and
loss
of
positive
fuel
pressure
to
the
injection
pump
will
result
in
injector
faults.
Engines & Generators
35