Testing; Sending Unit Installation; Troubleshooting; Fuel Starvation/Lean Mixture - Polaris 2007 Sportsman 500 EF Service Manual

6. Remove the 5 screws that secure the fuel sender to the tank.
7. Slowly lift the sender out of the tank. Lift the sender out at
an angle, so the float will more easily come out of the fuel
tank.

Testing

Refer to Chapter 10 for fuel gauge sending unit troubleshooting.

Sending Unit Installation

1. Reinstall the fuel sender with a new gasket, using care not
to bend or damage the float arm.
2. Install the 5 screws and torque the screws to specification.
Reconnect the sender and route the harness properly.
Sending Unit Screw Torque:
18--24 in.lbs. (2--3 Nm) in criss-cross pattern
3. Reinstall the PVT intake duct, gas tank vent line, front cab
assembly, and side panels.
NOTE: Properly route the gas tank vent line, use
tape to secure the vent line in place. (See Pic 1).
4. Reconnect the negative battery cable. Test the sender for
proper operation.
= T
CARBURETOR - SPORTSMAN 450

TROUBLESHOOTING

FUEL STARVATION/LEAN MIXTURE

Symptoms: Hard start or no start, bog, backfire, popping
through intake / exhaust, hesitation, detonation, low power,
spark plug erosion, engine runs hot, surging, high idle, idle
speed erratic.
• No fuel in tank
• Restricted tank vent, or routed improperly
• Fuel lines or fuel valve restricted
• Fuel filter plugged
• Carburetor vent line(s) restricted
• Plugged or restricted inlet needle and seat screen
or inlet passage
• Clogged jets or passages
• Float stuck, holding inlet needle closed or inlet
needle stuck
• Float level too low
• Intake air leak ( throttle shaft, intake ducts, airbox
or air cleaner cover)
• Jet needle position incorrect
• Incorrect pilot screw adjustment
RICH MIXTURE
Symptoms: Fouls spark plugs, black, sooty exhaust smoke,
rough idle, poor fuel economy, engine runs rough/ misses, poor
performance, bog, engine loads up, backfire.
• Air intake restricted (inspect intake duct)
• Air filter dirty/plugged
• Electric choke inoperative
• Incorrect pilot air/fuel screw adjustment
• Faulty inlet needle and seat
• Faulty inlet needle seat O-Ring
• Float level too high
• Poor fuel quality (old fuel)
• Loose jets
• Worn jet needle/needle jet or other carburetor
parts
• Dirty carburetor (air bleed passages or jets)
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