Polaris TX Starfire Owner's Manual page 77

CARBURETORS (Can't.)
When the fuel-air mixture is too lean:
( 1) The engine is over-heated.
(2) When the choke is opened, the condition becomes better.
(3) Acceleration is poor.
(4) The ignition plug is burnt.
(5) Rotations are irregular.
( 6) Exhaust gas is lean.
Our carburetor is so constructed that the parts to adjust vary
according to the degree of throttle opening. After having
checked whether the cause of disorder is due to an over-rich
mixture or to over-lean mixture, confirm what parts must be
adjusted for a specific throttle opening.
The relation between the degree of the opening of the throttle
valve and the functional systems and the parts to adjust is as
follows:
Throttle Valve
Degree of Opening
0 - 1/8 1/8 - 1/4 1/4 - 3/4 3/ 4 - Full Open
Functional System
Pilot System
Pilot System Main System
Main System
Main System
Parts to Adjust
Air Screw
Throttle Valve Jet Needle
Main Jet
Air Screw
When the condition of disorder and the degree of opening have
been confirmed, first check and clean the functional systems
and then adjust the parts in question.
DEGREE OF OPENING:
0-
1/8, air screw
When the opening is closed, the amount of air reduces and the
fuel-air mixture becomes rich.
When the opening is opened, the amount of air increases and
the fuel-air mixture becomes lean.
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