Sunbeam ALPINE I SERIES: APLINE II SERIES, Руководство по ремонту, Страница: 47 / 413

WSM, 124
Section B (Engine)
GENERATOR
To adjust belt tension
The generator .is driven from the crankshaft by a
belt which also drives the water pump and fan.
The belt is correctly tensioned when a total of
r
(16 mm.) movement can be obtained on the longest
run of the belt.
To adjust the tension, slacken the nuts and bolts at
,
the bottom front and rear of the generator, the link
locating bolt and the screw through the slot In the
strap. (See Fig. S). Move the generator about its
SLACKEN TO ADJUST
Fig. 5.
Generator belt adjustment
bottom two fixing bolts until the correct belt
tension is obtained, then retighten all bolts.
SPARKING PLUGS
Examination and cleaning
Figs. 6 to 10 Illustrate the various conditions in
which sparking plugs are found on removal and
these are as follows:-
NORMAL CONDITION-look for powdery
deposits ranging from brown to greyish tan.
Electrodes may be slightly worn. These are
signs of sparking plug used under normal
conditions of mixed period of high speed and
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low speed driving. Cleaning and regapplng of
the sparking plugs is all that is required (see
Fig. 6). White to yellowish powdery deposits
usually indicate long periods of constant speed
service or a lot of slow speed driving. Fig. 7
illustrates this condition. These deposits have
no effect on performance if the sparking plugs
are cleaned thoroughly at 3,000 mile (4,800km.)
intervals.
OIL FOULING-is usually identified by wet
sludge deposits traceable to excessive oil
entering the combustion chamber through
worn rings and pistons, excessive clearances
between intake valve guides and stems or worn
and loose bearings, etc. See Fig. 8. Hotter
sparking plugs may alleviate oil fouling tem­
porarily but in severe cases engine overhaul is
called for.
PETRQL FOULING is usually identified by dry
black fluffy deposits which result from incom­
plete combustion (see Fig. 9). Too rich an air­
fuel mixture, excessive use of hand choke or
faulty choke action can cause incomplete
burning. In addition, defective contact breaker
points or H.T. cables can reduce voltage
supplied to the sparking plug and causes mis­
firing. If fouling is evident in only a few cylin­
ders, stick! ng valves may be the cause. Excessive
idling, slow speeds or stop-and-go driving can
also keep plug temperatures so low that normal
combustion deposits are not burned off.
BURNT OR OVERHEATED sparking plugs
are usually identified by a white, burnt or
blistered insulator nose and badly eroded
electrodes (see Fig. 10). Inefficient engine
· cooling and improper ignition timing can cause
general overheating. If only a few sparking
plugs are overheated, the cause may be uneven
distribution of the coolant. Severe service,
such as sustained high speed and heavy loads,
can also produce abnormally high temperatures
in the combustion chamber, which necessitates
use of colder sparking plugs.
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