4.13
CARBURATION AND FUEL SYSTEM
© Copyright 2011 Polaris Sales Inc.
9923412 - 2012 Sportsman 400/500 and EFI Tractor Service Manual
NOTE: The starter jet is removable. Upon disassembly,
place the parts in a container for safe keeping.
Carburetor Cleaning
1. Thoroughly clean the carburetor body, jets, and all
passages with carburetor cleaner or electrical contact
cleaner.
2. If the carburetor is extremely dirty or contaminated
with fuel residue and varnish, soak for short periods
only in carburetor cleaner, and rinse in hot water.
3. Replace the jets if they have a buildup of fuel residue
or bacterial growth that cannot be removed. Even a
small amount of residue will reduce the flow
characteristics of the jet.
4. Verify all passages and jets are unobstructed by
spraying electrical contact cleaner through the
passages. CAUTION: Do not use wire or welding tip
cleaners as the orifice size may be altered.
5. Use low pressure air to dry carburetor body and all
components.
Carburetor Inspection
1. Inspect jet needle and needle jet for wear. Look for
discoloration, shiny spots, or an area that looks
different than the rest of the needle. The middle to
upper portion of the needle contacts the needle jet
and is the most likely wear point. If jet needle shows
signs of wear replace both the needle and needle jet
to prevent a rich condition. TIP: A worn needle jet is
difficult to spot. To check, slide a slightly larger new
jet needle into the needle jet and hold it to a light
source. Light will be visible between the needle and
needle jet if it is worn.
2. Inspect the inlet needle tapered surface for any sign
of wear or damage. Be sure the spring loaded pin is
free moving and returns freely when pushed. The inlet
needle and seat should be pressure tested after
assembly.
Protect eyes from contact with cleaner. Take
appropriate safety measures during these
procedures. Safety glasses and chemical resistant
gloves are required. Should you get cleaner in your
eyes or if you swallow cleaner, seek medical
attention immediately.
Carburetor cleaners can be extremely caustic.
Extended periods of soaking can loosen the
adhesive sealer on the passage drill-way plugs. Do
not soak rubber or plastic components (such as the
vacuum slide diaphragm, needle seat screen, or O-
Rings in caustic cleaning solutions. Damage may
occur. Do not use agitator-type carburetor cleaning
equipment. Rubber parts must be cleaned with mild
detergent and hot water only.
Inspect this
area
Jet Needle
Needle Jet
Good Condition
Worn, Deposits
Seat
Needle
Wear areas
To Next Page
Loading...
Need help?
General
