RUNNING IN YO UR NEW MOTORC
YC
LE
Al
though the new
pa
rts are machined
as
accurately as possible the
moving pa
rt
s need to mate with ea
ch
other or become what is known
as
'
·
b roke
n
~in".
At a low constant speed this would take a considerable
mile~
age, therefore the ideal method of
breaking~in
is
to increase pro-
gressively the load and length of time the load
is
maintained. These
machines
will travel at 50m.p.h. (80Km/h) with only a small throttle
opening
on
a level road without harm when new but any use of a large
throttle opening, even
in
a lower gear, other than for a very short time
may cause damage.
Change gear frequently
so
that the engine is always working easily,
neither pulling hard
in
a high gear nor revolving fast
in
a low gear. The
extra use of the gearbox helps
to
run
-
in
all the transmission parts. It
is
difficult
to
quote a set mileage but provided that the running-in
is
done
intelligently it should
be
possible
to
u
se
maximum performance after
1,500 miles (2.500Km). Whenever the maximum performance is used
it
is a good plan to snap shut the throttle for a moment occasionally
as
this
sucks a certain amount of
oil up
th
e cy
li
nders.
TO ADJUST THE VALVE
OPERATING MECHANISM
There are four adjuste
rs
on the rockers which are accessible after
re
moving the two inspec
ti
on ca
ps
f
ro
m the rocker boxes. A feeler gauge
of the correct thickness can be inserted u
nd
er each
ro
c
ker,
see
Fig
.
2.
The cl
ea
rance must
al
w
ay
s be
ch
ec
ked
wh
en
th
e engine
is
cold. It will be
easiest
to
find the correct
pOi
nt of t
he
stroke
to
adjust t
he
valve clearance
if you put the machine
on
th
e centre stand, engage
to
p gea
r,
and then
remove the sparking plugs. By turning
th
e rear wheel you can then turn
the crankshaft and position the valves.
Inlet
valves
(towards
the
rear
of
the
engine)
Turn the rear wheel until one of the inlet rockers moves downwa
rd
s,
th
us
opening
the
valve. When
th
is
valve
is
fully open the operating mechanism
of the other inlet valve
will be seated
on
the
base of
the
cam and the
clearance can now
be
checked and adjusted
if
necessary. The clearance
is
0.008in and is correct when a feeler gauge of this thickness
is
a
ti
ght
sliding fit between the valve tip and the adjuster. Tighten the locknut and
recheck
the
clearance. Having adjusted one inlet valve turn
the
rear
wheel until the valve which you have adjusted is now
fully open and
repeat the procedure
for
the other inlet valve.
13
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