Perkins 4.99 - Atomiser Procedures; Atomiser General Information and Testing

AIR CLEANERS AND FUEL SYSTEM-N.10
ATOMISERS
General
When replacing atomisers in the cylinder head, it is
essential that a new, correct type copper washer is
fitted between the nozzle body and cylinder head,
The correct torque for the atomiser securing nuts is
12 Ibf
It (1,7 kgf m) or 16 Nm,
The first symptoms of atomiser, trouble usually come
under one or more of the following headings:-
Misfiring,
2, Knocking in one (or more) cylinders,
3, Engine overheating,
4, Loss of power,
5, Smoky exhaust (black),
6, Increased fuel consumption,
Testing for Faulty Atomiser
If an atomiser is suspected of being faulty, try this
method to isolate it.
Slacken the union nut at the atomiser end of the
high pressure fuel pipe, If each atomiser is isolated
in turn in this way, (with the engine running at approxi-
mately 1,000 rev/min) tightening each union nut
firmly before proceeding to the next, then the faulty
atomiser, when isolated in this manner, will have little
or no effect on the running,
Warning
Great care should be taken to prevent the hands or
face from getting into contact with the spray, as the
working pressure will cause the oil to penetrate the
skin with ease,
Atomiser Pressures
Details of holders and nozzle types together with
pressure settings are given on Page 8,12,
NO ATTEMPT SHOULD BE MADE TO ADJUST THE
INJECTION PRESSURE WITHOUT AN ATOMISER
TESTING PUMP, IT IS QUITE IMPOSSIBLE TO ADJUST
THE SETTING OF ATOMISERS WITH ANY DEGREE OF
ACCURACY WITHOUT PROPER EQUIPMENT.
Atomiser Identification
Atomisers can be identified by code letters stamped
on a tab washer fitted under the spring cap nut (see
Fig, N,20) or alternatively, the code is stamped on the
atomiser body, Details of codings can be found on
Page 8,12,
1.
2,
3,
4,
5,
6,
7,
8,
9.
1O,
11,
12,
13,
::4------1
....... -----2
[!!ooIII~----5
10
.......------11
....... ----12
~ ...
13
Capnut
N20
Spring cap
Shim washer
Nozzle spring
Identification tab
washer
Spindle
Fuel inlet union
Nozzle holder body
Securing flange
Nozzle needle
Nozzle body
Nozzle capnut
Copper sealing washer