crankcase to engine base and lift top half of engine
clear
of
base.
Inspect
top
half of engine
and remove connecting rod
big
end
nuts and bolts, then remove big-end
caps. Push connecting rod
into cylinder as far as it will
go.
Next
remove
engine main bearing
plate, first removing nuts and dralu housing plate
off crankshaft.
Turn crankshalt until it rvill clear camshaft and
withclraw crankshaft.
2.
VALVE
GEAR.
(a)
Yalves.
When
valves have been
"
ground
in
"
after
decarbonising or when
a new valve
or
valves are fitted, they must
be
adjusted as
follows:
With
valves on their seats and
cold engine, check clearances
between
end of valve stems and top of tappet caps with feeler
gauge.
The
correct
clearances are as Ref. Pages
4 to 7,
and
are obtairred
by
fitting tempered steel shims betrveen
top
of ta.ppet
and tappet cap.
The shims are of various thicknesses.
Timing
Timing marks are
stamped
on crankshait pinion,
camwheel and
magleto driving wheel when the engine is erected.
A{ter dismantling
the engine, care must be taken to ensure that
these
marks
coincide
with each
other.
First
mesh
the camwheel and pinion
with their
marks corresponding, then revolve the
crankshaft until the mark
on the camwheel
points
towards the centre of
the
magneto
driving
wheel bush.
Now insert
the
magneto
driving wheel with its marks
corresponding
with the mark on
the camrvheel. For correct
valve
timing see
Pages 4
to 7.
(b) Camshaft
Drive.
(i)
R.emovtng and Replactng.
'fo
remove camshaft, the
crankshaft
must
first be removed
;
with crankshaft
removed, proceed
as follows:
Drive out
camsha{t
axle
toward
flywheel
side of engine. This operation
will
remove the
sealing
disc
and allow free exit of camshaft
axle.
Camshaft
may novr
be
withdrawn.
Repløcement
of
C
ømshøft.
Reverse operation of removal and replace
sealing disc.
(lt) Adjusting.
No means of adjustment
between
camrvheel
and driving
pinion
are
provided,
as
both
components
work
on
fixed centres.
Ptcs, 12
3. GOVERNOR.
(a)
AdJusting.
To adjust
governor
spring, slack ofi locking nut.
To
increase
engine
speed,
turn the knurled
adjuster in
a clockwise direction. To decrease
engine speed, turn in anti-clockwise
direction. Tighten locking
nut
when correct adjustment has been obtained.
(b) Repatring.
To
gain
access
to the
governor
for
repair
or
renewal
of component
parts,
disconnect throttle
link
from
governor
control arrn, remove
the 4 securing nuts and
remove
governor
cover. To
remove
governor
weights
withdraw
governor
actuating rod,
drive
out
governor
weight
fulcrum pins, remove
weights.
To remove
gear
wheel, turn engine
until small end of
taper
fixing pin is opposite
the
plug
in crankcase.
Remove
plug,
drive out taper
pin
and slide
gear
wheel
off magneto
driving shaft.
Norr.-If replacement of the
gear
wheel
is necessary,
gear
wheel
and
magneto shaft complete must
be
fitted as
gear
wheel and shaft
are drilled and reamed in position
for correct timing relation. To
remove
magneto driving
shaft
on the "
A
" type magtreto it is
necessary
to remove
magneto by
unscrewing
the 3 fixing bolts
and
sliding magneto sideways
to disengage
magneto
driving
plate.
To remove the
CJ. type
magaeto,
unscrew the two
fixing nuts and
pull
the
magneto
fonvard to disengage magaeto driving
plate.
4. FUEL
SYSTEM.
Fuel is fed
to the carburetter by
gravity
from tank. The
petrol
filter tap
is fitted
with a fine mesh filter and it
is
important to
periodically
clean
this by washing in petrol.
Each filter is fitted
with
a
tap which
requires
to be screwed either
fully
in
for
OFF,
or fully out for
ON,
to
ensure
leak proof operation.
Peor
13
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