Polaris TX Starfire Owner's Manual page 76

CARBURETORS (Can't.)
MAIN SYSTEM
(a) Be sure to use proper tools for disassembling the main jet
and the needle jet, and be careful not to make scratches when
reassembling. (Excessive tightening is a cause of disfigure or
damage.)
FLOAT SYSTEM
(a) Be careful not to bend the float guide pin in handling. If
bent, the pin causes malfunctioning of the float.
(b) The needle valve can be disassembled into the valve seat
and the float valve. When it is replaced because of wear or
scratches, use the complete needle valve assembly.
(c) Every time overhaul is performed, replace the float cham-
ber packing with a new one.
DISORDER AND ADJUSTMENT
A carburetor is a vessel with a lot of precision jets and a con-
stant fuel level. It is so constructed that when the negative
pressure of intake of the engine functions, proper concentration
of fuel-air mixture is obtained for the operation of the engine.
Accordingly, except for the mechanical disorders, most carbure-
tor problems are caused by an abnormal concentration of the
fuel-air mixture due to accumulated dirt and dust and wear
of parts.
Disorders of the engine due to an abnorma l fuel -air mixture
are as follows:
When the fuel-air mixture is too rich:
( 1) The rotations sound overwrapped and intermittent.
(2) When the choke is opened, the condition worsens.
(3) When the engine is warmed up, the condition worsens.
(4) The ignition plug becomes dark and dusty.
(5) Exhaust gas is rich.
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