A.J.S. 8, 14, Instruction Book, Page: 44 / 60

SPARKING PLUG (SINGLE OR 3-POINT)
The K.L.G. Type FE80 "Corundite" Plug is fitted to all models.
It has a thread of 14 mm. and the reach is ¾". The point gap is ·020 to ·022°. Check the
point gaps every time the engine is decarbonised and, if necessary, re-set the points.
See that the plug is fitted with its external seating washer.
Coat the thread with "Oil Dag" or Graphite paste.
Firmly tighten the plug by using the standard box spanner and
tommy bar (Part No. 017252). All that is required is a GAS-
TIGHT joint. Therefore do not over tighten, which will not
make a gas-tight joint more gas-tight, but can. and possibly will,
distort and damage the body of the plug.
Set the gaps to ·020 to ·022". Never try to move the central
electrode. To widen or narrow the gap between the electrodes
only move the earth (side electrodes). Check the gaps first
with a gap gauge. If they are too wide tap the earth (side
electrodes) towards the central electrode using preferably a
small copper drift and light hammer. Check the gaps between
each tap and stop when the gauge i s a nice sliding fit between
the central electrode and the three earth side electrodes.
If the gaps are too small to start with gently lever the earth
electrodes away from the centre electrode using a small screw-
driver and then tap them back as described above. Avoid
damaging the centre electrode and do not attempt to move the
electrodes apart by forcing anything between them.
For maximum efficiency, plugs should be cleaned at every 3,000
miles. To take the plug to pieces for cleaning, unscrew the gland
nut by holding the smaller hexagon on the gland nut upside down
in a vice and then using the box spanner to unscrew the larger
hexagon on the body.
Then lift away the central electrode assembly which should be
washed in petrol or paraffin. Then, using fairly coarse glass
paper, remove the carbon deposit and wash again.
The central firing point should be cleaned with fine emery cloth.
The inside of the body should be scraped clean with a knife and
finally rinsed in petrol.
There is an internal washer, between the insulator and its seating
in the body. On re-assembly lightly smear this with thin oil
and then screw up the gland nut sufficiently tight to give a gas-
tight joint.
Finally adjust the gap to ·020 to ·022".
Illustration 19
BATTERY TYPE 3-ER7L POSITIVE EARTH
"Dry charged" batteries are supplied without electrolyte, but with their plates in a
charged condition. No initial charging is required and to bring the battery into service
it is only necessary to fill the cells with electrolyte, prepared by mixing concentrated
sulphuric acid and distilled water. The cell filler holes are sealed to exclude moisture
and air before the battery is brought into service and the seals should be removed
immediately before electrolyte is poured in.
PREPARATION OF ELECTROLYTE. In the U.K. and countries where the
temperatures are normally below 90° F. (32° C.) electrolyte of 1·270 S.G. is required,
viz. 1 part acid (1·835 S.G.) to 2·8 parts distilled water. In tropical climates where
temperatures frequently rise above 90° F., electrolyte of 1·210 S.G. is recommended,
viz., 1 part acid (1·835 S.G.) to 4 parts distilled water.
W A R N I N G . ALWAYS ADD ACID TO WATER—NOT WATER TO ACID.
ON DRY CHARGED BATTERIES THE FILLING OF EACH CELL MUST BE COMPLETED
IN ONE OPERATION AND LEVELS RESTORED AFTER STANDING FOR AN HOUR
OR MORE BY SYPHONING OFF EXCESS ELECTROLYTE.
Electrolyte should be mixed in a glass or earthenware vessel, or lead lined tank.
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