Pilot Screw Adjustment - Polaris 2009 Trail Boss 330 Service Manual

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.
CAUTION:
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 are not exceeded.
Pilot Screw location
Brass Plug Installed
Brass Plug Removed

PILOT SCREW ADJUSTMENT

FRONT
(Engine)
Pilot Screw
View -- Right Cover Panel Removed
Pilot Screw
1. Start engine and warm it up to operating
temperature (about 10 minutes).
2. Turn pilot screw in (clockwise) until lightly seated.
Turn screw out the specified number of turns.
NOTE: Do not tighten the pilot screw forcefully
against the seat or the screw and/or seat will be
permanently damaged.
The pilot screw is set at the factory.
Each carburetor will have a slightly dif-
ferent pilot screw setting, the adjust-
ments below are the recommended set-
tings, the settings may differ from these
recommendations.
Pilot Screw Adjustment:
Trailboss 330 - - 2 Turns Out
3. Connect an accurate tachometer that will read in
increments of + or -- 50 RPM such as the PET
2100DX (PN 8712100DX) or the PET 2500 (PN
8712500).
4. Set idle speed to 1200 RPM.
throttle cable freeplay after adjusting idle speed
and adjust if necessary.
5. Slowly turn mixture screw clockwise using the
pilot screw wrench until engine begins to miss.
MAINTENANCE
Always check
2.15