Main System; Pilot Screw - Polaris Outlaw 500 Service Manual

FUEL SYSTEM / CARBURETION

Main System

As throttle valve (1) is opened, engine speed rises, and this
increases negative pressure in the venturi. Consequently the
vacuum slide (2) moves upward. The fuel in float chamber (3)
is metered by main jet (4), and the metered fuel enters needle jet
(5), in which it mixes with the air admitted through main air jet
(6) to form an emulsion. The emulsified fuel then passes through
the clearance between needle jet (5) and jet needle (7), and is
discharged into the venturi (A). Mixture proportioning is
accomplished in needle jet (5); the clearance through which the
emulsified fuel must flow is determined ultimately by throttle
position and vacuum slide height.
1
A
5
4.8

Pilot Screw

The pilot system supplies fuel during engine operation with the
throttle valve closed or slightly opened. The fuel/air mixture is
metered by pilot screw and discharged into the main bore
through the pilot outlet.
The pilot screw is calibrated at the factory to meet
EPA / CARB regulations for air quality standards
and is sealed with a brass plug to prevent
tampering. Removal of the tamper proof plug is
not permitted. For service purposes, cleaning of
the pilot circuit can be done only by a certified
repair shop to ensure air quality standards
2
7
6
3
4
CAUTION
are not exceeded.
Pilot Screw Location
Brass Plug Installed
Brass Plug Removed
RepairPro Service Manual