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Page SlO
Fuel Jnjection System-continued
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previously, no force wiil be needed to make a good
joint.
No force should be used.
Use only a standard open-ended
i in. by ,1ç in.
spanner.
If the union is tightened excessively the nipple
may collapse and split. Tbe same danser exists
if the pipe is not square to and central with the
union.
When changing an atomiser always remove the
pipe entircly. Never undo only ODe end, leaving
the other tight. Never bqid the pipe.
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FIG. 56. 5howing plalc Cor holding Atorniscr whilc
is bcinl disrnantlcd.
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Of ten tbe pamcular atomiser or atomisers
causing trouble maf he determined by releasing
thc pipe union nut on each atomiser in turn, with
the engine running at a fast .. tick-over." This will
prevent fuel heing pumped through the nozzle
to the engine cylinder, thereby altering the engine
revolutions. If after slackening a pipe union nut
tbe cngine revolutions remain constant, this
denotes a faulty atomiser.
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Tbe nuts from the flangc ofthe doubtful atomiscr
should bc rcmovcd and tbc complete unit witb-
drawn from tbc cylinder head and tumcd round.
atomiscr nozzle outwards, .. unwipcd" on its
pipc, and tbc unions re. tightcacd. After slacken-
ing tbc uni ons of tbc other atomiscr pipes (to
avoid the possibility of tbc enginc starting), the
enginc should bc tumcd until tbc nozzlc sprays
into tbc rir, whcn it wiJl bc sccn at once if tbc spray
is in order. If tbc spray is unduly .. wct" or
.. streaky .. or obviously to anc side, or tbc atomiscr
nozzlc .. dribbles," tbe spray holes should be
probcd with the special tooi ET.120. (See fIg. S.9).
Ir aftcr probing tbc spray holes, tbc condition of
tbc atomiser is still faulty, removc tbc complete
unit.
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MAINTEN AN CE.
Atomisers should he taken out for examination
at re gul ar intervals. How long this interval should
be is difficult to advise, because of the widely
different conditions under which engines opera te.
When combustion conditions in the engine are
good and the fuel tank and filtering system are
maintained in fust class order, it is of ten sufficient
if the atornisers are tested twicc yearly.
For detailed times refer to periodical mainten-
iince, Section F. It is no use taking atomisers
out for attention ~ess the equipment described
on page S.ll is available, or spare atomisers are
at hand for substitution.
The nearer thc ideal conditions of good fitting
with adequate cooling and absolutely clean fuel
arc realised, the less attention the atomiscrs will
nced, and so the langer their efficient life. In
this conncction, sinco there is no other item of
tbc equipment upon which thc performance of
an engine depends so much, it pays the uscr
handsomely to sec that the engine never runs
with anv of its atomisers out of order.
Great care shou!d be taken to prevent the hand
from setting into contact with the spray. as the
working pressure wi!l cause oil to penetrate the
skin with case.
Troubles in Semce.
The first symptoms of atomiser troubles usually
rail in ODe or more of the following headings ;-
I. Knocking in one (or more) cylinders.
2. Engine overheating.
3. Loss of power.
4. Smoky exhaust (black).
5. Increased fuel consumption.
Tbc spare atomiser from the tooi kit should be
tltted, the faulty unit being placed in the tooi kit
securely wrapped in ciean grease-proof paper or
rag for attention on the maint~nanc~ !'I..nch
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