Starter Unit; Fuel-Air Mixture Too Lean; Fuel-Air Mixture Too Rich - Suzuki GS850G Service Manual

FUEL
SYSTEM & CARBURETORS
CARBURETORS
IMPORTANT:
The GSMOG carburetors have been
rnanuf~crured
and
adjusred
ro
special
precise tolerunc~s
lo
meet [he EPA
emission levels. Before
attempting to
servic~ or repair the carburelor
assemblies,
thoroughly
read und un-
dersfand the following inslrucrions
canrain~d in this chapter, and
also
careful/v
review
rhe
informalion
con-
toined in /he ernission conrrol sysrems
and regulorions chapter. IF
contains very
imporfan, and spec rfic information on
/he
carbureror components.
DO NOT ADJUST THE AIR SCREW AND
PlLOT SCREW. Both of these components
are pse-set
at
the factory using very
specialized equipment. They can not be reset
to the
exact
setting determined by
the factory.
Refer to the emission control systems and
0
regulation chapter for further information.
Descxipt
ion
Thir motorcycle has four carburetors, each of
which must be
so adjusted properly to assure
engine performance.
The link a r m is moved hy the
two
throttle
cables that are connected to the throttle grip
to open or
close
all
carburetor throttle
valves
a t the same time.
Each carburetor has four units for regulating
and
supplying
fuel. There is the starter unit
for supplying a rich fuel-air
mixture
when
starting the engine, a pilot unit for supplying
fuel
when
the engine is idling, a main unit for
supplying Fuel
when the
engine is
running
at
medium-or high-speed, and a float unit for
maintaining a constant carburetor fuel level.
The carburetors mix gasoline with air. and
regulate
the
mixture. Carburetor malfunc-
tioning
or trouble generally occurs due to a
bad
mixing
ratio, which is the result of
wearing, biocking
by foreign matter,
or an
improper fuel level. The following are some
of the symptoms
of
a Faulty carburetor.
Fuel-air
mixture too
lean
1. The engine
becomes overheated.
2. The
engine
runs
well when the starter is
opened further,
3. Poor acceleration.
4. The ?park
plugs become
overheated.
5 . Engine speed
is
irregular
6. Exhaust gas is light.
Fuel-air
mixture too rich
1. The engine is sluggish, and does
not run
smoothly.
2. The engine runs badly
when
the starter is
opened
further.
3, The engine
runs
badly
after
being
warmed up.
4. The engine runs well when the air filter
is removed.
5 ,
The spark plugs
gel soiled with carbon.
6 . Exhaust
gas
is blackish
in color.
STARTER UNIT
The starter unit is a starting aid
device which
st~pplics a
highly colicen
tra tcd
fuel-air
rnixttire
to
a cold engine at
initial
starting.
I t
ctsnsiqts
of
a starter jel
0,
starter
pipe
@ ,
and starter plunger
3 .
Refer io Fig. 9-5. Tc
activate
the starter unit closc the
throttle
valve.
open the starter plungers fully by
pulling out
choke knob.
and activate the
starter or kick, Then
the engine will generate
negative pressure
to
draw the fuel tllrough the
fuel
injection ports.
The fuel is metered by [he starter jet, is mixed
witl.1 the
air coming from
the float cl~arnber in
the
starter
pipe, sucked
i n t o the starter