Westerbeke WPDS-20 Technical Manual page 15

14
Fig. 1 for mechanically governed and Fig.
2 for hydraulically governed pumps.
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Fig. 2
If the fuel system is fitted with a
fuel feed pump, slacken both the filter
bleed screw "A" and the injection pump
fuel inlet union "B", and operate the hand
priming lever of the feed pump until fuel
free from air issues from both the vents.
Tighten both the vent connections. In a
gravity fed fuel system turn on the fuel
and carry out the same procedure with the
bleed screw and fuel inlet.
Slacken the vent valve fitted to one of
the two hydraulic head locking screws
"c"
and the bleed screw "D" on the governor
housing. Operate the hand priming lever of
the feed pump, until fuel free from air
bubbles issues from the vent
"c"
and then
tighten this bleed screw.
NOTE: The space within the governor hous-
ing (vented by screw "D") is normally
filled, and its contents lubricated,
by fuel oil back-leaked from the pump
plungers, the pump rotor and the ad-
vance device if fitted. This is the
normal way in which this space becomes
filled with oil and this can naturally
take a long time at feed pump pressures.
However, if the reason that the pump is
being vented is because a pipe line or in-
jector or filter element has been changed
or serviced or the system has run out of
fuel, then the governor housing will still
be filled with fuel oil and bleeding by
means of the hand priming lever of the
feed pump will suffice. In this event,
close the governor bleed screw "D" as sOon
as fuel free from air issues from the vent.
If, however, a new pump has been fitted
to the system, then its governor housing
will most likely be empty of fuel oil and
bleeding proceeds as follows.
Leave the governor bleed screw "D"
slackened. Next slacken any two injector
pipe line connections at the injector end.
Set the throttle to the fully open pos-
ition and turn the engine until fuel free
from air flows from the unions. Then re-
tighten the loosened injector pipe unions.
Start the engine and run it at fast
idling speed until air-free fuel exudes
from the governor bleed screw "D". Tighten
this screw and stop the engine.
Governing may be erratic during this
procedure, therefore stand by to stop the
engine should any excessive engine speed
develop.
RECOMMENDED SPARES Owners are often in
doubt as to the amount of fuel injection
equipment spares to carry. A great deal
depends upon the use of the craft and its
location. General coastal use in well-
populated areas is one thing, but voyaging
up the Amazon delta, for example, would be
quite different and would require a com-
prehensive spares kit.
Generally speaking, the average boat
owner is within relatively easy reach of
service centers and requires spares only as
insurance against breakdown and for general
servicing within the scope of the owner or
crew.
A suitable kit for such a purpose would
consist of a replacement filter element and
a set of sealing and "0" rings for each
filter. Spare bleed screws for pumps and
filters are also required, for screws are
easily lost or damaged in a boat when bleed-
ing the system. A full set of high pressure
injection pipes should also be carried, for
a fractured or cracked pipe could occur at
any time and no patching is possible with
these pipes. The correct set of pipes can
be obtained from the engine manufacturer's
agent or service center and will be supplied
already bent to shape and cleaned intern-
ally with both ends plugged against the
entry of dirt. They will be supplied pack-
ed as a set and it is important to keep
them this way until required for use. It
is vitally important that the internal sur-
face of the pipe is kept scrupulously
clean until fitted to the engine.
A spare set of fuel injectors of the
right type and correctly set for the par-
ticular engine together with a set of the
correct seating washers will not only en-
able defective injectors to be changed
when required but will also permit engine
use while one set is away being serviced.