Polaris A09BA50FA, User Manual

Page: 115 / 256

FUEL SYSTEM/CARBURETION
4.11
5. Install the pilot mixture screw, spring, washer, and
O-ring as an assembly. Lubricate the O-Ring with
oil or light grease before installation. CAUTION:
Do not damage the O-ring during installation.
Turn the screw in until it lightly contacts the seat.
Back out the specified number of turns. NOTE:
The final pilot (idle) mixture must be adjusted with
the engine running. Refer to Page 2.12.
Pilot Mixture Screw Base Setting
(Set at Factory)
Refer to Specifications Page 1.4
FLOAT HEIGHT
ADJUSTMENT
1. Place the carburetor on a level surface as shown
at right to remove weight from float arm. In this
position, the float tongue will rest lightly on the
inlet needle valve pin without compressing the
spring.
Float Height:
Std: BST 40 14.7mm (.58
″
)
±
1 mm
NOTE: On BST 40 carburetors, it is important to
press in on the float assembly as shown, to fully seat
the float assembly.
BST 40
2. Measure the height from the float bowl mating
surface to the top of step in float as shown. Both
sides of float should be parallel to each other. The
measurement should be made at the mid-point on
the top of the float using Float Adjustment Tool
(PN 2872314) or a vernier caliper.
When
measuring the height be sure the inlet needle
valve spring is not compressed.
3. If adjustment is necessary, bend the tongue
slightly. Be sure float measurement is even on left
and right side.
Bend to adjust
float
Float arms even