2016 Polaris Sportsman 570 Fuel Pump: Essential Guide for Repair & Maintenance

Understanding the 2016 Polaris Sportsman 570 fuel pump – its function, common failure symptoms, replacement process, and maintenance tips – is critical for keeping your ATV running reliably. This crucial component delivers pressurized gasoline from the tank to the engine's fuel injectors. A malfunctioning pump can leave you stranded or cause serious engine performance issues. This comprehensive guide provides practical information to diagnose problems, replace the pump, understand part options, and maintain your Sportsman 570's fuel system effectively.

The Role of the Fuel Pump in Your Sportsman 570

Every internal combustion engine, including the 570cc single-cylinder powering your Sportsman, requires a precise mixture of fuel and air ignited within the combustion chamber. The fuel pump is the heart of the fuel delivery system. Its primary function is to consistently draw gasoline from the fuel tank and push it at the correct pressure through the fuel lines to the fuel injector(s). The Polaris Sportsman 570 uses an Electronic Fuel Injection (EFI) system. This system relies heavily on the electric fuel pump located inside the fuel tank. The pump assembly typically includes the pump motor, a strainer or "sock" filter (to catch larger debris before it enters the pump), and the electrical connector. The EFI control module monitors engine needs and commands the fuel injector to open for precise durations, but this system depends entirely on the pump maintaining sufficient pressure to allow that injection to occur properly. Without adequate fuel pressure, starting becomes difficult, engine power drops significantly, and overall performance degrades.

Identifying Symptoms of a Failing Fuel Pump

Recognizing early signs of fuel pump trouble allows you to address the problem before a complete failure leaves you stranded on the trail or unable to start the ATV. Pay attention to these common symptoms associated with a weakening or failing 2016 Sportsman 570 fuel pump:

  1. Starting Difficulties: The most frequent sign. As the pump weakens, it struggles to build sufficient pressure immediately when you turn the key. This causes extended cranking times. You might turn the key and hear the engine crank over multiple times before it finally starts, if it starts at all. In severe cases, the engine may crank normally but fail to ignite entirely.
  2. Loss of Power, Hesitation, or Stalling: When the engine demands more fuel during acceleration, climbing hills, or operating under heavy load, a failing pump cannot supply the required volume or pressure. This causes noticeable power loss. The ATV may stumble, hesitate, or feel like it's surging under throttle. It might even stall completely during operation, particularly when you attempt to accelerate hard. Stalling can occur unexpectedly at idle or while riding.
  3. Sputtering or Stalling at High RPM/Load: Similar to power loss, the engine might run adequately at low speeds and throttle positions but sputter, misfire, or stall when RPMs increase or load is high. The pump simply cannot keep up with the engine's increased fuel demands.
  4. Engine Won't Start (No Fuel Pressure): A completely dead fuel pump results in no fuel delivery. The engine will crank normally but refuse to start. You will not smell gasoline strongly from the exhaust during cranking attempts.
  5. Whining or Humming Noise from Fuel Tank: While a faint hum is normal when you first turn the key to the "ON" position (prime mode) and for a few seconds after startup, an unusually loud, high-pitched whining, buzzing, or groaning noise coming from the vicinity of the fuel tank is a strong indicator the pump motor is straining or failing. Listen carefully near the rear of the ATV.
  6. Intermittent Operation: Problems that come and go can be frustrating. The ATV may start and run fine one minute, then exhibit symptoms the next. This can be caused by electrical connection issues at the pump harness connector or internal pump motor wear causing intermittent contact.
  7. Check Engine Light (CEL) Appearance: While not as common for pump failure itself on this model compared to other EFI issues, a severe problem causing long-term fuel pressure loss can sometimes trigger the Check Engine Light. It's more likely related codes involve fuel pressure delivery or mixture problems.

Diagnosing 2016 Polaris Sportsman 570 Fuel Pump Problems

Before assuming the fuel pump is bad and purchasing a replacement, it's crucial to perform some basic diagnostic steps to confirm the issue. Avoid unnecessary expense and ensure you fix the real problem.

  1. Listen for Prime Cycle: When you turn the ignition key to the "ON" position (don't crank), you should hear a distinct humming or buzzing sound from the fuel tank area for approximately 2-5 seconds. This is the pump pressurizing the fuel line and injector rail. No sound during prime usually points directly to: A dead pump motor, failed relay, blown fuse, severed wiring, or a problematic ignition switch connection. Note: Let the system sit for several minutes to depressurize slightly to hear it prime again.
  2. Check Fuses: Locate the main fuse box on your Sportsman 570 (consult your owner's manual – typically under the front hood/seat area or side panel). Inspect the fuse related to the fuel pump circuit. It is often labeled "EFI," "Fuel System," "F/Pump," or similar (specific fuse box diagrams vary). Visually inspect the fuse element for a break. Even if it looks intact, test it with a multimeter for continuity or swap in a known-good fuse of the same amperage. Also, check the main 30A fuse near the battery.
  3. Inspect Fuel Pump Electrical Connector: The fuel pump assembly has an electrical connector under the ATV near the tank or accessed by removing the rear rack or seat. Unplug this connector. Examine it closely for any signs of damage, corrosion, melted plastic, bent pins, or moisture intrusion. Clean both halves thoroughly with electrical contact cleaner and a small brush. Securely reconnect it. Wiggle the connector gently while trying to start the ATV – if it starts, the connector or wires likely have an internal fault (bad pins, broken wiring).
  4. Perform Fuel Pressure Test (Recommended): This is the most definitive test for pump function and overall fuel system health. You need a compatible ATV/Small Engine Fuel Pressure Test Kit. Locate the Schrader valve test port on the fuel injector rail (looks like a tire valve stem cap). Connect the test gauge securely to this port. Turn the ignition key to "ON" to activate the prime cycle. Observe the pressure reading. The specified pressure range for a Polaris Sportsman 570 EFI system is typically 57 PSI +/- 2 PSI (around 393 kPa). If pressure is significantly lower, fluctuates wildly, doesn't hold steady after prime stops, or builds extremely slowly, the pump is likely faulty. If no pressure is registered at all, it confirms a complete pump failure or severe blockage. Always perform this test safely – relieve pressure via the test port before disconnecting the gauge, and avoid sparks/flames. Check your specific service manual for exact pressure specs and procedures.
  5. Check Fuel Relay: The fuel pump relay provides high-current power to the pump when commanded by the ECU during prime and engine operation. Locate the relay box (often near the fuse box). Identify the fuel pump relay using the diagram on the lid. Swap it temporarily with another identical relay in the box (like the starter relay). Attempt to start the ATV. If it now primes and starts, the original relay was bad. Listen/feel for a click when turning the key to "ON".
  6. Rule Out Simple Issues: Ensure the fuel tank has a sufficient amount of gasoline. Low fuel levels put additional strain on the pump and can sometimes expose a weakening pump. Make sure the fuel line isn't pinched or kinked anywhere between the tank and the engine. While less common with EFI, verify the vent line on the fuel tank cap isn't severely blocked, creating a vacuum in the tank that restricts flow.

Detailed Step-by-Step Guide to Replacing the 2016 Sportsman 570 Fuel Pump

Once diagnosis confirms a faulty fuel pump, replacement is necessary. This requires draining the fuel tank, accessing the pump assembly inside, and installing the new pump module. Patience and careful handling of fuel components are essential.

  • Tools & Materials Needed:
    • Replacement 2016 Polaris Sportsman 570 Fuel Pump Assembly (Complete Module)
    • Socket Set & Ratchet (Metric Sockets)
    • Screwdrivers (Phillips & Flathead)
    • Needle Nose Pliers
    • Shop Towels / Rags
    • Fuel-Resistant Gloves & Safety Glasses
    • Drain Pan (Large enough for tank's fuel capacity)
    • Small Flat Container (for retaining rings/clips)
    • Gasoline Container (for drained fuel)
    • Fuel Line Disconnect Tool(s) (Optional, helpful)
    • Pliers for Hose Clamps (if applicable)
    • New Fuel Pump Module Lock Ring (Optional, if old one is damaged)
  • Preparations:
    • Park the ATV on a level, well-ventilated surface, away from sparks or flames. Engage the parking brake.
    • Place the drain pan directly under the fuel tank area.
    • Relieve Fuel System Pressure: While optional (systems usually depressurize quickly), you can locate the Schrader valve on the fuel rail and gently depress the center pin with a small screwdriver or valve core tool while holding a rag over it to catch any residual fuel spray. Wear eye protection!
    • Disconnect Battery: Always disconnect the negative (-) terminal of the battery first. This eliminates any risk of electrical sparks while working on the fuel system. Cover the terminal end.
    • Drain the Fuel Tank: Locate the fuel line outlet near the bottom of the tank. Follow it to find the quick-disconnect fitting or clamp securing it to the pump module. Place the drain pan directly under this connection. Carefully disconnect the fuel line using a disconnect tool if it's a quick-connect type, or loosen the clamp if hose-clamped. Have plenty of rags ready to catch drips. Allow all the gasoline to drain into the pan. Some tanks also have a separate drain plug, but disconnecting the main feed line is usually sufficient.
  • Removing the Fuel Tank & Accessing the Pump:
    1. Disconnect All Fuel Lines & Vent Hoses: Identify all hoses connected to the fuel tank. This typically includes the main fuel supply line to the engine (already disconnected if you drained it), the vent hose (runs to the charcoal canister or cap vent), and possibly a smaller return line (less common). Use pliers for any hose clamps or the quick-disconnect tool as needed. Label hoses if unsure. Disconnect any electrical connectors attached directly to the tank or pump assembly (mainly the pump's large connector). Carefully note their routing.
    2. Remove Tank Mounting Hardware: Locate and remove all bolts, straps, or brackets securing the fuel tank to the ATV's frame. These are usually found at the front and rear corners of the tank beneath the seat area or rear cargo rack. Support the tank securely as the last bolts are removed. Note spacer locations.
    3. Carefully Lower and Remove the Tank: With all lines disconnected and bolts removed, carefully lift or lower the fuel tank away from the ATV frame, tilting if necessary to clear obstacles. Place it securely on a stable, clean work surface with the pump access cover facing upwards. Tanks are awkward! Get help if needed.
    4. Clean Around the Pump Access Cover: Thoroughly clean the area around the large plastic access cover on top of the fuel tank with a rag. You want to prevent any dirt or debris from falling into the tank when you open it.
    5. Remove Pump Module Lock Ring: Locate the large plastic lock ring securing the pump assembly to the tank. This ring has notches. Using a blunt drift punch or large screwdriver handle placed firmly against a notch, carefully tap the lock ring counter-clockwise (Lefty-Loosey) with a hammer. DO NOT use excessive force. Work around the ring, tapping each notch until the ring spins freely. Remove the lock ring.
    6. Lift Out the Pump Assembly: Carefully lift the entire pump assembly straight up and out of the tank. It may be sealed with an O-ring, requiring a slight wiggling motion. Take care not to damage the fuel level sender float arm.
    7. Remove Pump Module Components: Before disassembling the module itself, note the position and orientation of the strainer/filter sock and the large rubber cushion seal around the top edge. Identify how the electrical connector is routed. Often, the entire module comes with the new pump assembly, making transfer unnecessary.
  • Installing the New Fuel Pump Assembly:
    1. Transfer Components (If Needed): If your replacement pump is just the bare pump module without the integrated housing, sender, etc., you'll need to carefully transfer those components from your old pump assembly onto the new pump. Follow the specific instructions included with your replacement pump meticulously. Most modern replacements, however, are complete assemblies for the 2016 Sportsman 570, meaning this step is avoided. Using the complete assembly is strongly recommended.
    2. Clean the Tank Opening: Before inserting the new assembly, clean the inside rim of the tank opening and remove any old O-ring debris.
    3. Install New O-Ring: Ensure the new, large rubber O-ring is properly seated in the groove on the tank's opening or on the new pump module (depends on design – see new pump instructions). Lubricate it lightly with a smear of clean engine oil or silicone grease (specified in Polaris manuals) to aid sealing and prevent pinching. Do not use petroleum jelly.
    4. Insert New Pump Assembly: Carefully align the new pump assembly into the tank opening, ensuring the electrical connector and fuel level float arm are oriented correctly to fit without binding. Lower it straight down until fully seated.
    5. Install Lock Ring: Place the lock ring back onto the tank opening over the pump module. Align the tabs. Using the drift punch or screwdriver handle again, gently tap the lock ring clockwise (Righty-Tighty) until it is securely seated against the stop. Ensure it feels tight and all tabs are evenly engaged. Do not overtighten, as the plastic ring can crack.
  • Reassembly & Testing:
    1. Carefully Reinstall the Tank: Lift the tank back into position on the ATV frame. Reinstall all mounting bolts, straps, and brackets according to their original positions and torque specifications. Avoid overtightening plastic components.
    2. Reconnect Fuel Lines & Vent Hose: Reattach all fuel lines and the vent hose securely. Ensure quick-connects "click" fully into place and any hose clamps are positioned correctly and tightened. Ensure the vent line is routed away from heat and exhaust without kinks.
    3. Reconnect Electrical Connectors: Reattach the main fuel pump electrical connector and any other connectors you disconnected from the tank. Ensure they snap firmly together.
    4. Reconnect Battery: Reattach the negative (-) battery terminal and tighten securely.
    5. Prime the System: Turn the ignition key to "ON". Listen for the distinct humming of the new fuel pump running for its prime cycle (around 2-5 seconds).
    6. Start the Engine: Turn the key to start the engine. It may crank slightly longer initially as fuel fills the lines. It should start smoothly and idle consistently.
    7. Check for Leaks: BEFORE riding or reassembling body panels, meticulously inspect all fuel line connections you touched (feed line at tank, injector rail, etc.) for any signs of fuel leaks. Sniff for gasoline odors. Run the engine for a few minutes at idle, then rev slightly, and check again. Do not skip this step – fuel leaks are a fire hazard!
    8. Reinstall Body Panels/Seat/Rack: Once confident there are no leaks and the ATV is running normally, reinstall any body panels, cargo racks, or the seat that you removed to access the tank area.

Choosing the Right Replacement Fuel Pump

Selecting the correct replacement part is vital for reliability and fitment.

  1. OEM (Polaris Original Equipment Manufacture): Advantages: Guaranteed perfect fit, exact performance specifications, and material quality designed for this specific model. Part Number: The common OEM pump assembly part number for the 2016 Sportsman 570 is 3083749. Check with your dealer or parts counter for confirmation. Disadvantages: Significantly higher cost.
  2. Quality Aftermarket Brands: Several reputable manufacturers produce high-quality aftermarket pumps designed specifically for the 2016 Sportsman 570. Brands like Quantum Fuel Systems, Delphi, Carter, and TI Automotive have strong reputations. Advantages: Significant cost savings while maintaining good quality and fitment. Many come with warranties comparable or better than OEM. Disadvantages: Requires careful research to ensure you select a brand known for quality control; potential slight variations from OEM specifications.
  3. Avoid Ultra-Cheap Pumps: Pumps found at rock-bottom prices online from unknown brands carry substantial risks. Quality control is often poor, materials may be substandard, and they frequently lack the correct pressure specifications or flow rates. The fitment might be off, requiring modification. These pumps are prone to premature failure, potentially leaving you stranded again soon after replacement. The minimal savings are rarely worth the hassle and potential engine damage risk from improper operation.

Proper Fuel Pump Maintenance for Longevity

While fuel pumps eventually wear out, proper maintenance can significantly extend their lifespan:

  1. Use Clean, Quality Fuel: Contaminants like dirt, water, and ethanol phase separation byproducts are major pump killers. Purchase gasoline from reputable stations with high turnover. Avoid filling up right after a station's underground tanks have been refilled (stirs up sediment).
  2. Avoid Consistently Low Fuel Levels: Running the tank very low increases the amount of sediment the pump potentially draws from the bottom of the tank (which gets concentrated when low). It also reduces the cooling effect gasoline has on the submerged pump motor. Keep the tank at least 1/4 full when possible. Refill before extended storage.
  3. Treat Fuel for Storage: Ethanol-blended gasoline attracts moisture and degrades over time. If storing your Sportsman 570 for more than a month, add a quality fuel stabilizer formulated for ethanol blends (like Stabil Ethanol Treatment or Sea Foam) to a full tank of fresh gas. Run the engine for 5-10 minutes to circulate the treated fuel through the entire system, including the pump. The stabilizer prevents oxidation and phase separation and lubricates the pump seals.
  4. Replace Fuel Filters Periodically: The Sportsman 570 has two fuel filters protecting the pump and injectors:
    • Strainer "Sock": Located on the intake of the pump assembly inside the tank. It traps larger debris.
    • In-Line Filter: Many models have an additional, finer-micron inline filter located somewhere along the fuel line between the tank and the fuel rail. Check your owner's manual for location (often under the seat or hood area).
      Replace both the in-line filter and the pump module strainer sock according to the service interval in your owner's manual (often every 200-300 hours or 2 years). Replacing the entire pump module usually includes a new sock. Consider replacing the in-line filter whenever replacing the pump itself.
  5. Keep Tank Cap & Vent System Functional: Ensure the fuel cap seals correctly and the tank vent hose/knee vent system is clear. A blocked vent creates a vacuum in the tank that the pump has to fight against, putting extra strain on it and reducing flow.

Troubleshooting After Pump Replacement

If you've replaced the fuel pump and the Sportsman 570 still won't start or runs poorly:

  1. Confirm Battery Strength: A weak battery can spin the starter but cause low voltage issues affecting the pump. Ensure the battery terminals are clean and tight. Test battery voltage (>12.6V static).
  2. Recheck All Connections: Double-check the main fuel pump electrical connector under the ATV near the tank. It must be fully seated and locked. Reconfirm the fuel line connections at the pump module and the engine rail – ensure they are secure and correctly seated on the barbed fittings.
  3. Verify Fuel Flow: Disconnect the fuel line at the injector rail outlet. Place the end into a small container. Have an assistant turn the ignition key to "ON" (do not crank). You should see a strong, steady flow of fuel pumping into the container during the prime cycle. If flow is weak or intermittent, the issue lies with the pump installation or upstream components.
  4. Inspect Fuses & Relay Again: It's possible a fuse blew immediately upon installing the new pump or a relay is still faulty. Recheck all relevant fuses and consider swapping the relay again.
  5. Check for Pinched/Kinked Fuel Line: Trace the fuel line carefully. Did it get pinched between the frame and tank during reassembly? Look for sharp bends or kinks that restrict flow.
  6. Ensure Adequate Fuel: This sounds obvious, but did you add fresh gasoline to the tank after reassembly? Did you reconnect the vent line? A tank vacuum will prevent flow.
  7. Consider Professional Help: If basic checks don't resolve the issue, deeper electrical diagnostics involving the ECU, pump relay control, or ground connections might be needed. Consult a qualified Polaris technician.

Final Conclusion

A functional fuel pump is non-negotiable for reliable operation of your 2016 Polaris Sportsman 570. Recognizing symptoms like hard starting, power loss, sputtering, or unusual noises from the tank allows for timely diagnosis. Confirming failure involves listening for the prime cycle, checking fuses and connections, and ideally, performing a fuel pressure test. Replacing the pump requires careful fuel handling, methodical disassembly to access the tank-mounted module, and precise reassembly with a quality OEM or reputable aftermarket part. Prioritizing preventative maintenance – using clean fuel, avoiding constant low levels, stabilizing fuel for storage, and replacing filters – will maximize the life of your new pump. By understanding and proactively caring for your Sportsman 570's fuel pump, you ensure countless trouble-free miles on the trail.

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