A.J.S. 16 Instruction Book - D Y N A M O
(b) The contact breaker lever also requires lubrication and the complete contact breaker
must be removed for this purpose. Take out the hexagon-headed screw from the centre
of the contact breaker and pull the contact breaker off the tapered shaft on which it fits.
Then push aside the lever retaining spring, prise the lever off its bearing and lightly smear
the bearing with clean engine oil. When replacing the contact breaker, take care to
ensure that the projecting key, on the tapered portion of the contact breaker base,
engages with the keyway cut in the magneto spindle, otherwise the timing of the magneto
will be upset. Tighten the hexagon-headed screw with care: it must not be too slack,
nor must undue force be used.
Adjustment every 3,000 miles
Remove the contact breaker cover and turn the engine until the contact points are fully
opened. Check the gap with a gauge having a thickness of ·012" (Spanner 015023 has a
gauge of this thickness as an integral part of it). If the setting is correct the gauge
should be a sliding fit, but if the gap varies appreciably from the gauge it should be
adjusted.
Keep the engine in the position to give maximum opening of the contact points, slacken
the lock nut on the fixed contact point and turn the contact screw, by its hexagon head
(use spanner 015023) until the gap is set to the gauge. Finally, tighten the lock nut
and re-check the setting.
Cleaning every 5,000 to 6,000 miles
Take off the contact breaker cover and remove the contact breaker. If the contact
points are burned or blackened, clean them with a fine carborundum stone or with very
fine emery cloth, and afterwards wipe away any dust or dirt with a petrol moistened
cloth. After replacing the contact breaker check the point gap and, if necessary, re-set it.
Remove the high tension pick-ups (held by swinging spring clips), wipe clean and polish
with a fine dry cloth. The high tension pick-up brush must move freely in its holder.
If it is dirty, clean with a cloth moistened with petrol. If the brush is worn to within
8" of the shoulder it must be renewed. Treat both pick-ups and their brushes.
While the pick-ups are removed, clean the slip ring track and flanges by holding a soft
cloth on the ring by means of a suitably shaped piece of wood, while the engine is slowly
turned.
If, on inspection, the high tension cable shows signs of perishing or cracking, it must be
replaced by a suitable length of 7 mm. PVC covered, or neoprene ignition wire.
Magneto removal and fitting
The magneto is "spigot fitting" and is retained to the crankcase by two studs and one
bolt.
To remove the magneto it is necessary to:
Take away the timing gear cover.
Withdraw the driving gear from the magneto shaft. (Already described in the Engine
Section.)
Disconnect the high tension wires from the sparking plugs.
Disconnect the ignition control cable.
Remove the nuts from the two studs and one bolt that secure the magneto body to the
crankcase and the unit is free to be taken away.
The re-fitting is done by the above procedure reversed and the method of timing has
already been described in the Engine Maintenance Section.
D Y N A M O
A LUCAS type E3L-LI-0 dynamo is fitted. It is anti-clockwise in rotation. The
cutting in speed is 1,050—1,200 r.p.m. at 6·5 volts and at 1,850 to 2,000 revolutions per
minute it gives an output of 8·5 amps at 7 volts. The positive brush is earthed. The
two exterior terminals are marked " D " and " F " , indicating the respective terminals
for the output and field wires that lead to similarly marked terminals on the Regular
Unit.
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