Amal Carburetter
AMAL CARBURETTER
(Models 5T. TR5, TI00
&
TttO)
The
AMAL
needle jet carburetter
is
fitted to all the above mentioned models and,
unltxs the machine is to be used for some special purpose, we strongly recommend
that the settings are not interfered with. The settings are arrived at after careful
experiment and
It
is unlikely that a different setting will improve the fuel con-
sumption, or increase the maximum power output. Alternative settings are however
listed for the models TI00
&
TI10 when the
air
filter
is disconnected.
During the early life of the machine
it
is advisable to remove the float bowl and
clean
it
out occasionally to prevent the jets becoming blocked.
A
common cause of
erratic running at low speeds, explosions in the silencers and poor pick-up when
accelerating
is
a CHOKED SLOW RUNNING ORlFlCE
IN
THE JET BLOCK. To
remedy this fault, the carburetter mixing chamber must be completely dismantled
and the jet block withdrawn to gain access to the orifice. To clear, push a thin
strand of wire through the hole to dislodge any foreign matter. Wash the jet block
in petrol and dry
off
with pressure air to ensure that
all
passage ways are perfectly
clear.
OPERATION
OF
CARBURETTER PARTS
Throttle Stop Screw. This screw should be set to open the throttle sufficiently
to keep the engine running
at
a low tick over when the twistgrip
is
shut off.
Pilot
Air
Screw. To set the idling mixture, this screw should be set in or our to
enrich or weaken, normal number of turns is about
2f.
The screw controls the
suction on the pilot petrol jet by metering the amount of air which mixes with the
petrol.
Needle and Needle Jet.
A
tapered needle
is
attached to the throttle and either
allows more or
less
petrol to pass through the needle jet as the throttle
is
opened
or closed throughout the range, trcept when idling or nearly full throttle.
The taper needle position in relation to the throttle opening can be set according to
the mixture required by fixing
it
to the throttle with the needle clip spring in a
certain groove, thus either raising or lowering
it.
Raising the needle enriches the
mixture; lowering
it
weakens the mixture at throttle openings from a quarter to
three quarters open. Machines are delivered from the factory with the needle in
the fourth notch from the top, and the
needle should be lowered to the middle notch
after
1,000
miles (1,500 Kms.).
Throttle Valve Cut-Away. The atmospheric side of the throttle
is
cut away to
influence the depression on the main fuel supply and thus gives a means
d
tuning
between the pilot and needle
jet
range of throttle opening. The amount of cut-away
is
recorded by a nunlber marked on the throttle viz.,
613
means throttle type
6
with
No.
3
cut-away; larger cut-aways. say
4
and
5
give weaker mixture and
2
and 1 richer
mixtures.
To Next Page
Loading...
Need help?
General
