Setting The Plug Points - BSA B31 Instruction Manual

-
A
liSht deposit
due
to
any of
these causcs
can easily
be
cleaned off, but
if
it
is allowed to
accumulate,
particularly
inside
the body, the ptug may
spark internally
with
an
adverse effect on
engine
perfoftnanc€-if,
indeed,
ir
does
not
stop the
engine altogether. The plugs should
be
cleaned and resled at regllar
interuals, and
it
is suggested
rnar
rhrs servtce be
pertbrmed at your
garage
on
a
special
'Air
Blast'service unit.
lfeventually
the cleaning process
Ialls
to
restore
lhe plug !o ils
original condition of
emcieDcy,
it
should
be replaced by
a new
one.
Fig. 15. Sc
ing
the
plug pornrs
.
When
lnsp€oting a plug. also
check the gap
between
the
poinrs.
This shoutd be
.018-.020
in.
(.45_.50
mm.)
and adjustment should
be made by bending
the side
wiri
Gee
Fig.
l5).
Neyer
åtfempt
to
moye Oc
centre
electuode,
and
it
is alwaJs ad'"isable to
use
lhe
special
plug
gap rooi
lrusrmteo.
obtalnatrle
at
2/_ trom
any Champion
plug
stockist
or
from
lhe
Champion Sparking
plug
Co.
Ltd.
Felrham, Middlesex.
Feelei gauges
are atrached to vcrify
conect gap.
When refittinS
a
plug,
make slrle that
the copper
warsher
0;t:,
34
35
is
not
defective
in
any
way.
If it
has become
worn
and
flattened,
fit
a new one
to
€nsure a
gastightjoillt.
Screw
the
plug down by
hand as
far
as
possiblq
then
use
a
spanner
for
tightening
only. Always
use
a
tubular
box spanner
to
avoid
possible fiact$e
of
the insulator
and do
notin
any circumstances use an
adjustable spanner
Paint splashes, accumulation
of
grime and
dust-
etc.,
on
tle
top half
of
the insulator
are
often responsible
for
poor plug pcrformance.
Plugs should be wiped
fre4uenlly
with
a clean rag.
Air
Cleån€r (when fitted to
Comp.
or
Plunger models).
This
being
of
the
oil dip
typc, needs
to
be
dismantled and
cleaned
periodically.
The
filter ele&ent should
be washed
thoroughly
in petrol, allowed to
dry, and
then
submerged
in light
engine
oil for
a few
minutes. Then take out,
allow
the surplus
oil to
drain
of
and
.eassemble.
Atu Cleåner
(fitted
to
swinging
arrn machhes). This
is
in front of lhc
battery cårrier, and
is
coupled
to
the
carburetter
by
means
of a
rubber
elbow. The
filter
element must be remov€d
periodicålly
when
it
should
be
washed
thoroughly
in petrol, dried,
and then
submerged
in thin
oil
(SAE20) for a few minutes. Theo take out,
allow the
surplus
oil to
drain ofr and reassemble. This
operation is carried out
as
follows:-
The
Cleaner
cover
is attached by
two
sqews in elongated
slots, the lower
to the frame member below the
seat and
the other
to
the battery
strap.
The rubber connection
to
the carburetter should
be
left
in
position
on the
carburetter
inlet
stub and
slipped
off
the cleaner cover.
The
ltlter
is
held
in
the cleaDer
cover
by
a wire circlip.
Note: The domed surface
of
the
p€rforated retaining
disc
must be replaced upwards.
Cylinrler
Head. After the machine has covered
its
6rst
250 miles from new
or
after
decarbonising,
check
the
tightness of
the
cylinder head bolts.
If
they need
to
be
tightened
work in
diagonal order
to
ensure
that
the head
is tightened evenly, otherwise
distortion
may result.