Ii'
I
allow
the
engine lo lilbour orr hills in
a hiah
acitr
whcn
I
change
to a
lower
gear
would casc the load on thc engir)c.
Do not
let the oil level in the tank
get
too low,
as
economy
in oil may
prove
very
expensive at a later date,
Running consistently
with the oil level too low may
couse
the oil to
become unduly hot. It must be lemembered
that the oil cools as well as
lubricates,
and a
new
enginc
tetrds to run a
little hotter
lhan one that
is well "run-in."
One more tip
that is
worth
while-add
a
small
quantity
of upper cylinder
lubricant to the
petrol
each time
the
tank is
rcplenished- If this is difficult to obtain, add
about
atr eggcupful of
engine oil to every 2
galloDs
of
petrol.
HOW
THE LTJBRICATION SYSTEM
WORKS
The
engine lubication system
(see
Fig. 2) is of
tho
dry sump
type operated by a double
gear punp,
situated
in the bottom
of the crankcase on the right-hand side.
All oilways
are intemal except for the supply and letum
pipes
from
the tank and the oil fe€d to tho valve rockers.
The
oil ffows from the tank-through a 6lter in the tank
to
the supply
pump
(the
inside crankcase union) aud
thence
past
the
pressure
valve ,4 to the oilways feeding
|he cåm spindles and along the hollow mainshaft to tbe
big-eod bearing.
After
lubricating the big-end alld circulating through
the
engine in the folm of mist, the oil &ains dolln
through
a filter in thc bottom of the
qankcase,
from
which
it is drawn by the rctu.n
pump (lower
pair
of
gears) past
ball valve
q
and
delivered up the retum
pipe (outer
crankcase union) to thetank, Oilis
fed through
a union
situated
in
the
pipe
betweeD
the rcturD
pump
and the tank, to
the rooker spindles, ard after lubricating
the rockers
and enclosed valv€s, is retumed to the clank-
case
through an external oil
pipe
attached to
the
base of
lhe inlet valve spring housing. In the case of aluminium
engines, the oil retums to the crankcase
via
the
push
aod
lunnel.
Incorrect
seating
of
the ball valve
I may allow oil
to transfer from
the
tadk
to
the
engine whilst the machine
is stationary. In
this event, unscrew the
plug
retaining
the valve,
and retuove spring and ball. Clean the ball
and
its seating and replace. If
nec€ssary,
to
ensure
a
close
fit
between ball and seat the ball
should be rcplac€d on
its seating
and dealt a shary blow with
a light hammer
and
punch
to
make
certain that the ball
beds on the seat
in
a
satisfactory
manner.
If the ball valve c should
get
stuck
in its
seating,
there
will be do retum
of oil to
the tank. To correct, remove the
cover
plaie
I
below the
pump,
insert a
pi€oe
of wire iDto
the valvc orifice, and lift the ball off
its
seating to free
iL
To check the flow ol oil in the lubricatiDs system,
reftove
the tank filler cap whilst the eogine is runnhg. Oil
should
be seea
issuiog
from the retum
pipe
from the øankcåse.
Any
restriction
in the
pressure
release
pipe
(see
Fig. 2)
in
the
tank
will cause an increase
in
pressure
inside the
oil tank, and will result in leakage of oil at the 6ller cap.
This can be rectified by inserting a lenglh of flexible wire
into the
pipc
at its lower end
(just
in flont of the r€ar
mudguard) and
pushing
the wire right up the
pipe,
thus
cleadog any obstruction. In the cas€ of Comp. models
atrd machines with swinging arm rear suspemion which
are 6tted with an oil brcather
tower
(Fig.
2a)
it is
only
oecessary to keep the short length of tube
clear which
projects
horizontally from ii under the seat.
To remove the
oil
tank filter for cleaning on Comp.
models and machines fitted with
plunger
frames
(se€
Fig. 2) remove the oil
pipe
banjo union
plug
at the bottom
of the tank. The filter will come out with the
plug.
On
models 83l and 833 it is
preferable
to
remove the toolbox
first. This is secured by three nuts and bolts, one through
the mudguard valance and two through the short verticål
strip oD the chainstay.
On swinging
arm models
(Fig.
2a)
it is not necessary to unscrew the oil
pipe
union, the
oil
tank filter being attached to the larg€ chromed drain
piug
screwed in the side of the tank, The supply
pip€
which will be seen wher the drain
plug
is
.emoved, draws
its
oil
rhrough
the filte!. The filter should be
placrd
in a
oan
large enough
to cover it with
petrol,
and thoroughly
washed. Before
rcplacing make sule that it is
quite
dry
of
petrol.
The
pump
filter can be nithdrawn after removing
the
To Next Page
Loading...
