BSA Winged Wheel W1 Instruction Manual page 19

Needle .Jet.
This normal]y requires no maintenarice, a.s any
i-oreir,m matter whicn finds its way to this point is
not likcly to bec,)me lodged in the jet, owing to its
size a,rid the action of the needle.
Jet Needle.
As described above, the position of the jet needle
affects the mixture strength. When the B.S.A.
WINGED WHEELS are sent out from the fa.ctory
the clip is engaged in the centre notch, which
gives the best avera.gc setting. If it is íelt, how-
ever, that the mixture is somewhait on the wea.k
side, a,nd possibly a little more power is necessary,
although this will proba,bly be at the expense of a
slightly heavier fuel coQsumption, this ca.n be pro-
vided if the clip is moved inwards to the next notch
Sïmilarly, the mixture can be weakened in the
iI`terests oí extreme economy, a,lthough with a,
slight power loss and a tendency to overhea.t, if the
clip is moved outwards to the next notch. Unless
vou have had considerable experience of ca,rbur-
etter tuning, however, you will be well advised to
act in this respect on the advice of your dealer
Main Jet.
As can be ima.gined in the case oí a. sma,1I engine
such as the B.S.A. WINGED W'HEEL, the hole
in the main jet is very tiniy, and ca.n easily be
choked by even microscopic íoreic,m ma,tter. Ir-
regula.r or erratic running may be attributed to
this cause, and if the jet should be stopped up it
will be found in most cases tha.t it can be clea,ned
by placing it between the lips and blowing sha.rply.
This method of clearing the jet is prefera.ble to
poking the dirt out with a piece of wire because
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this operation is liable to damage the jet orifice
with a consequentlv adverse eÍÏect on performance
a.nd consumption.
It is rare that the main jet will become choked.
There is, liowever, a. very small hole in the float
chamber ca.p K, between the gauze filter £, and the
float needle va.lve. It is much more Hkely that
stoppage of this hole may be the causo if petrol
starvation is expcrienced. Clea.r by similar action
to that advised for the main jet, and ín addition,
careíully dry out the filter chamber below the
gauze filter in case water has a.ccumulated above
the feed hole.
WICO-PACY ELECTRICAL EQUIPMENT.
DESCRIPTION.
This Flywheel lgnition Genera.tor Unit embodies
two assemblies, na,mely the flywheel and the stator
which carries the ignitiori coil, lighting coil, conta,ct
breaker unit and coridenser. The cam is fitted on
to the crankshaft, Iocated by a, key and hcl(l in
position by the flywheel.
The ignition unit provides a high performance
spark output over a very wide range of speeds,
about 9,000 volts being obtained, at only 350 r.p.m.
rising to l2,000 volts at 6,000 r.p.m., a.nd it ha,s
been íound possible to maintain a large enough air
gap between rotor and stator tó ensurc a trouble-
free svstem.
A characteristic of the ma,gneto is that its spairk
output wi]l not vary over a wide timing range, thus
renderiI]g frequent adjustment of the contacts un-
necessary, and at the same time allowing a íair
tolerance for the accuracy of the setting. A íurther
feati..re oí the magneto are the a.ccessibility and
ease of adjustment of tlie contact breaker without
the necessity of rem()virig the flywheel.
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