A.J.S. 3.46 H.P., Руководство пользователя

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Timing. —If the magneto has been removed from the machine it will be necessary
to see that it is timed correctly after it is refitted.
The sprocket on the armature shaft of the magneto is supplied with a vernier timing
adjustment, which allows a very accurate and
certain method of fixing the drive after the
correct setting has been arrived at. The setting
of this vernier adjustment may at first sound a
trifle complicated, hut in reality it is perfectly
simple. Filled to the armature shaft of the
magneto is a sleeve (1), which has thirteen holes
ranged in a circle. Fitting over a collar on this
sleeve is the chain sprocket (2), which has
twelve holes similarly arranged. Now on the
sprocket on engine driving shaft and on the
magneto shaft will be found an arrow. These
must point to each other before anything else is
done. The first thing then in timing up is to
set these two arrows so that they face exactly
towards each other. To do this turn engine
over until the arrow on the driving sprocket is
pointing directly towards the arrow on the mag-
neto sprocket. This latter should he held free
in the fingers and moved a tooth backwards or
forwards in the chain until the correct setting
is arrived at. When this is so, place the magneto
sprocket on to the sleeve, and turn the armature
shaft of magneto until a mark found punched
over one of the twelve holes on the sprocket
exactly registers with a similar mark on the out-
side of the collar of the sleeve. It will now be
found that the marked holes in sleeve and
sprocket respectively exactly coincide, so that
all that has to he done is to push the peg
washer (3) into these holes, which effectively pre-
vents the sprocket from moving from its correct
setting, and tightly screw up the sleeve lock
nut (4), which can be done without fear of
the timing shifting in the process, as is often the case with other methods. As a means
of verifying the timing, or if the sleeve (1) has been removed from the magneto armature
shaft, set the piston its correct distance from top of compression stroke (see ignition timing
for details), making sure it is not on the exhaust stroke,
With the piston in this position take off the sleeve lock nut on magneto sprocket and remove
the peg washer. This will leave the armature free from the engine drive, but still connected
Illustration 5.
VERNIER TIMING ADJUSTMENT.
CONTACT BREAKER.
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