Polaris 570 Sportsman Fuel Pump: Symptoms, Testing, Replacement, and Maintenance Guide

The fuel pump in your Polaris 570 Sportsman is essential for delivering gasoline from the tank to the engine at the correct pressure. When it malfunctions or fails, your ATV won't run properly, leaving you stranded. Symptoms often include hard starting, sputtering, loss of power, or a complete failure to start. Diagnosing the issue requires systematic testing of the fuel pressure and electrical components. Replacing a faulty fuel pump module is the definitive solution, requiring careful work around the fuel tank, and following key preventative maintenance can significantly extend the lifespan of the new pump and prevent future failures.

Understanding the Fuel Pump's Role in Your Polaris 570 Sportsman

The fuel system in your Sportsman 570 relies on a constant, pressurized flow of fuel reaching the fuel injectors. The electric fuel pump, typically located inside the fuel tank, performs this crucial duty. It draws fuel from the tank through a pre-filter (often called a strainer), pressurizes it, and sends it forward through the main fuel line to the fuel rail and injectors. This pressure is not constant; the Engine Control Module (ECM) regulates it electronically. A fuel pressure regulator maintains the necessary pressure level within the system for optimal engine performance across all operating conditions. When the pump fails to generate sufficient pressure, or fails entirely, the engine lacks the fuel it needs to run correctly, manifesting in various drivability problems. Ensuring this pump functions reliably is fundamental to your ATV's operation.

Recognizing Symptoms of a Failing Fuel Pump (Polaris 570 Sportsman)

Early detection of fuel pump problems can save you time, frustration, and potentially avoidable towing costs. Key signs to watch for include:

  • Engine Cranks But Won't Start: This is a primary indicator. If you hear the engine turning over normally when you press the start button but it doesn't fire up, and especially if this issue becomes progressively worse, fuel delivery (likely involving the pump or its relay) is a prime suspect. Check simpler causes first, like a dead battery or clogged fuel filter, but persistent no-start situations often point to the pump.
  • Hard Starting, Especially When Warm: If your 570 Sportsman struggles to start after being ridden and sits for a short while (engine still warm), a failing pump might be the culprit. Internal wear can cause the pump to generate less pressure as it heats up during operation, leading to insufficient fuel delivery once you try to restart.
  • Sputtering, Hesitation, and Loss of Power Under Load: Experiencing significant power loss during acceleration, climbing hills, or hauling loads? A weak pump may not be able to supply enough fuel under high engine demand, causing the engine to stumble, buck, or hesitate severely. You might notice this happens most noticeably when the fuel level in the tank is lower (e.g., below half).
  • Engine Surging or Inconsistent RPM: Although less common with a failing pump itself than with regulator issues, erratic engine behavior like surging or RPM fluctuations unrelated to throttle input can sometimes be tied to an unreliable fuel supply stream. However, electrical issues are a more frequent cause of surging.
  • Abrupt Engine Stalling: An engine that suddenly dies while idling or moving, particularly if accompanied by any of the other symptoms above, can point towards a fuel pump cutting out completely, potentially due to an internal electrical fault.
  • Unusual Noise from the Fuel Tank: While some faint humming from the pump area is normal when you first turn the ignition key (before starting), listen for unusually loud whining, buzzing, or grinding noises originating from under your seat near the fuel tank. Increased noise often indicates impending failure or excessive wear.
  • Noticeable Drop in Fuel Economy: While many factors affect mileage, a significantly struggling fuel pump forces the engine control module to compensate, potentially enriching the fuel mixture unnecessarily, leading to poorer gas mileage than usual.

Testing Your Polaris 570 Sportsman Fuel Pump (Step-by-Step)

Before concluding the pump is faulty and proceeding with replacement, conducting basic tests is highly recommended. This helps ensure you're addressing the root cause and not replacing a good part.

  • Step 1: Verify Fuel Pump Activation Sounds:

    1. Turn the ignition key to the "ON" position (do not start the engine).
    2. Listen carefully near the seat/rear fender area. You should hear a distinct humming or buzzing sound lasting 2-5 seconds as the pump primes the system.
    3. If you hear no sound at all, the problem is likely electrical (relay, fuse, wiring, connector, ignition switch, or ECM issue) or the pump motor itself has completely failed.
    4. If you hear unusually loud grinding, whining, or screeching, the pump's internals are likely damaged and struggling.
    5. If the sound only happens occasionally or intermittently, suspect an electrical connection problem or failing pump windings.

  • Step 2: Check Key Electrical Components:

    1. Locate the Main Fuse Panel: Typically under the front hood.
    2. Find the Fuel Pump Fuse: Consult your owner's or service manual for the exact fuse location (e.g., often labeled "EFI", "INJ", "P/L", or "FUEL P/L"). Pull it out.
    3. Inspect the Fuse: Visually check the thin metal strip inside the clear plastic body. If it's visibly broken or melted, replace it with one of the exact same rating (amperage).
    4. Test the Fuel Pump Relay: Identify the fuel pump relay (again, consult the manual for location/identification). Sometimes swapping it with a known good relay of the same type (e.g., the horn relay) is the quickest test. If the pump works with the swapped relay, the original relay is bad. Listen for a faint click when the ignition is turned on, but a click doesn't guarantee the relay contacts are good.
    5. Inspect Wiring Connections: Trace the wiring harness from the fuel tank's electrical connector back towards the fuse box and ECM. Look for any obvious damage, chafing, corrosion (especially green or white powder), bent pins, or loose connectors. Disconnect plugs, clean contacts with electrical cleaner if corroded, and reconnect securely.

  • Step 3: Perform Fuel Pressure Test - Critical Step:
    This is the most definitive test to determine if the pump is generating the necessary pressure. You need a quality fuel pressure gauge kit designed for fuel injection systems. Warning: This involves pressurized gasoline - use extreme caution; avoid sparks/flames; have a fire extinguisher nearby.

    1. Locate the Schrader Valve: Near the throttle body, find the small valve on the fuel line (looks like a tire valve stem cap). This is the test port. Relieve Residual Pressure: Put on safety glasses and gloves. Cover the valve area with a thick rag. Carefully depress the center pin of the Schrader valve with a small screwdriver. Fuel spray may occur - this is normal. Wipe up fuel immediately.
    2. Connect the Gauge: Attach the appropriate adapter from your fuel pressure test kit securely onto the Schrader valve. Ensure the gauge valve is closed.
    3. Turn Ignition ON: Cycle the ignition key to ON. The fuel pump should prime, and the pressure gauge should jump. Note the reading as soon as the pump stops priming (this is "prime" or "static" pressure).
    4. Check Holding Pressure: Wait a few minutes. Pressure may drop slightly but should stabilize. If pressure drops to zero very quickly, there's a leak in the system or the pump's internal check valve is faulty.
    5. Start the Engine: Start the ATV and let it idle.
    6. Measure Running Pressure: Note the pressure reading at idle.
    7. Test Under Load: Gently increase engine RPM (blip the throttle) while observing the gauge. Pressure should increase slightly with throttle opening. Check service manual specifications – but typically expected pressures are:
      • Prime/Static Pressure: Often around 38-42 PSI (consult manual for exact spec).
      • Idle Pressure: Slightly lower than prime pressure, often around 35-40 PSI.
      • Pressure Under Load: Should rise significantly (potentially 40-45+ PSI) as the throttle opens, then regulate back down quickly when returning to idle.
    8. Interpret Results:
      • No Pressure or Extremely Low Pressure: Strong indicator of failed pump, clogged tank intake screen (strainer), severely blocked fuel filter, or major fuel line obstruction. Testing downstream of the filter helps isolate the pump/strainer.
      • Low Pressure: Indicates a weak pump, partially clogged strainer/filter, restricted fuel line, or failing fuel pressure regulator (requires additional specific testing - see manuals).
      • Pressure Drops Rapidly After Pump Shutoff: Points to leaking fuel injector(s), faulty fuel pressure regulator diaphragm, or a bad check valve inside the pump assembly.
      • Pressure Higher Than Spec: Less common, usually indicates a stuck closed fuel pressure regulator.

  • Step 4: Consider Pump Relay Bench Test: If you have doubts about the relay beyond the simple swap test, some auto parts stores offer free relay testing. Alternatively, basic bench testing involves applying 12 volts to the correct pins and listening for a click while checking continuity on the switched contacts with a multimeter.

Replacing the Fuel Pump Module on a Polaris 570 Sportsman

Warning: This procedure involves working with gasoline. Perform in a well-ventilated area away from sparks or flames. Wear safety glasses and gloves. The fuel pump assembly is typically sold as a complete "fuel pump module" assembly, which includes the pump itself, strainer (sock filter), integrated fuel level sending unit (float), module housing, seals, gasket(s), and electrical connector. Replacing just the bare pump inside is possible but often more challenging and less reliable than replacing the entire module.

Necessary Tools & Parts:

  • New OEM or High-Quality Aftermarket Fuel Pump Module
  • Socket Set & Wrenches
  • Torx Driver Set (common sizes like T20, T25, T30)
  • Pliers (Needle-nose, Channel-lock)
  • Hose Clamp Pliers (or small screwdriver)
  • Shop Rags/Clean Towels - Lots!
  • Fuel-Resistant O-Ring Grease/Assembly Lube
  • New Fuel Line Clamps (small, screw-style recommended for reassembly)
  • Fire Extinguisher (nearby)
  • Fuel Containers - at least 5 gallons capacity
  • Fuel Resistant Silicone Sealant (if specified by module or manual)
  • Replacement Fuel Filter (if applicable, highly recommended)
  • Service Manual (For specific torque specs and connector details)

Replacement Procedure Outline:

  1. Prepare the ATV:

    • Park on a level surface. Engage the parking brake securely.
    • Siphon Fuel: Syphon as much fuel as possible out of the tank through the fill neck into approved fuel containers. Removing fuel reduces spill risk and makes the tank lighter. Get it as low as possible. Do not rely solely on running the engine until it stalls – you need the tank nearly empty.
    • Disconnect Battery: Disconnect the negative (-) battery cable first. This eliminates electrical spark hazards.
    • Remove Seat and Related Components: Remove the seat. Often, rear cargo racks, side panels, or fender sections need removing to fully access the fuel tank cap area. Consult your manual.

  2. Access the Fuel Tank:

    • Disconnect Fuel Lines: Locate the main fuel supply line running from the tank to the engine. Identify the small vent/rollover valve line(s) often connected near the tank cap. Label lines if necessary. Use small pliers or a screwdriver to carefully loosen the spring clamps (if equipped) and slide them back. Be prepared for residual fuel to drip. Plug the engine-side fuel line if possible to prevent debris entry. Drain remaining fuel from the tank lines into a container.
    • Disconnect Electrical Connector: Unplug the main electrical connector for the fuel pump module (located on the tank cap assembly).
    • Remove Fuel Filler Neck Hose Clamp: Loosen the large clamp connecting the fuel filler neck to the tank.
    • Remove Tank Fasteners: Identify and carefully remove the bolts, nuts, or straps securing the tank itself. Tanks are usually secured with bolts/nuts around the perimeter of the tank cap plate and often have supporting straps underneath toward the front. Note their locations for reassembly. Support the tank as you remove the last bolts.

  3. Remove Fuel Tank & Module Cap Assembly:

    • With all fasteners, lines, and connectors detached, carefully lift the tank away from the ATV frame. Have a helper if needed due to weight/residual fuel. Place it securely on a stable, protected work surface. Ensure the tank is stable.
    • Clean Work Area: Thoroughly clean the dirt and debris from around the fuel module assembly sealing surfaces before proceeding. This prevents contamination inside the tank.

  4. Service/Replace Fuel Filter: (Highly Recommended) If your 570 has an external inline fuel filter between the tank and the engine (common), now is the time to replace it. Discard the old filter properly.

  5. Remove Old Fuel Pump Module:

    • Locate the large locking ring securing the module assembly to the top of the fuel tank. This ring is usually plastic and threaded, or sometimes uses locking tabs.
    • For Threaded Rings: Use a large flat-blade screwdriver or punch inserted into the notches on the ring. Carefully tap the ring COUNTER-CLOCKWISE (as viewed from above) using a mallet and punch/screwdriver until it loosens and can be unscrewed by hand. Warning: Force can break plastic rings - if stuck, use penetrating fluid carefully around the threads.
    • For Locking Tabs: Use pliers or pry tools to carefully disengage each locking tab following the manufacturer's sequence. Avoid breaking the tabs.
    • Lift Module Assembly: Once the locking ring is fully disengaged, lift the entire fuel pump module assembly straight up and out of the tank. Be cautious – the fuel level float arm is delicate. Note its orientation! Have rags ready as residual fuel will pour out. Drain fuel from the module assembly over a container.
    • Remove Strainer: If the new module doesn't include a strainer sock or yours looks heavily clogged, gently remove it from the pump inlet tube. Compare old and new modules carefully.

  6. Install New Fuel Pump Module:

    • Clean Tank: Inspect the inside of the fuel tank for debris, rust, or sediment. Remove all foreign matter. Flushing with clean unleaded gasoline can help. Ensure the tank sealing surface is perfectly clean and free of old gasket material, dirt, or damage. A lint-free rag lightly dampened with fuel helps.
    • Prepare New Module: Compare the new module exactly to the old one. Ensure all connections are identical. Install the new strainer sock if it wasn't pre-installed. Apply a thin, even film of fuel-resistant lubricant/assembly grease to the large O-ring seal that goes between the module flange and the tank. This is crucial for sealing. Use only grease specified for use with fuel (e.g., Dow Corning 111, Ford TA-31, etc.). Do not use petroleum jelly or engine oil!
    • Position Module: Align the module assembly carefully into the tank opening. The float arm must align correctly inside the tank. Rotate the module if necessary until it drops fully into place and sits flush. Ensure the O-ring remains in its groove and seated properly – no pinches.
    • Install Locking Ring: Hand-thread the locking ring onto the tank opening CLOCKWISE (as viewed from above) until snug. If it has tabs, engage them correctly. Do not overtighten! Tighten plastic rings finger-tight plus 1/8 to 1/4 turn max with a screwdriver/punch. Plastic cracks easily. Refer to manual torque if applicable (rare on plastic rings). Tap gently and evenly around the ring. Avoid excessive force.
    • Test Operation (Before Tank Install): This step is invaluable but requires caution:
      • Temporarily reconnect the electrical connector to the module.
      • Reconnect the fuel supply line to the module outlet port.
      • Place a large container under the open fuel line. (A helper is useful).
      • Momentarily reconnect the battery NEGATIVE cable.
      • Turn the ignition key ON (do not start). You should hear the new pump prime. Fuel should pulse forcefully out of the open fuel line.
      • Turn key OFF. Disconnect battery NEGATIVE cable again immediately.
      • Securely plug the end of the fuel line for the next step.

  7. Reinstall Fuel Tank:

    • Carefully maneuver the fuel tank back into position on the ATV frame. Reconnect the vent/rollover line(s) securely.
    • Reconnect the main fuel supply line. Install new screw-style fuel line clamps. Slide the clamp onto the hose, connect the hose fully over the barbed fitting, then slide the clamp back into position and tighten it securely. Avoid overtightening which can cut hoses. Spring clamps are difficult to reuse reliably, so screw clamps are preferred.
    • Reconnect the electrical connector to the module cap.
    • Reattach all tank mounting bolts/nuts/straps. Follow the service manual tightening sequence and torque specifications if available. Avoid uneven tightening causing leaks.
    • Reattach the fuel filler neck hose and tighten the clamp securely.
    • Reinstall all body panels, racks, etc., that were removed.

  8. Final Checks & Start-Up:

    • Double-check all fuel line connections and hose clamps are tight and secure. Wipe connections dry then observe for leaks later.
    • Reconnect the battery NEGATIVE cable.
    • Turn ignition key ON. Listen for the pump priming cycle (2-5 seconds). Check for fuel leaks around the module cap area and at all connections underneath.
    • If no leaks, start the engine. It may crank slightly longer than normal initially as the system purges air. Once running, observe for smooth idle and absence of previous symptoms (stalling, power loss). Inspect all fuel connections again thoroughly while the engine runs and after you shut it off. Any fuel drips require immediate shutdown and repair!

Preventative Maintenance to Extend Fuel Pump Life (Polaris 570 Sportsman)

Proactive care dramatically reduces the likelihood of premature fuel pump failure and associated headaches. Implement these practices:

  • Use Clean, High-Quality Fuel: Contaminants (dirt, water, debris) are a pump's worst enemy. Fill up at reputable stations. Avoid storing the ATV with ethanol-blended fuel (E10, E15) whenever possible. Ethanol is hygroscopic (absorbs moisture), leading to phase separation and corrosion inside the tank and module.
  • Regularly Replace the Fuel Filter: If your 570 has an external inline fuel filter, adhere strictly to the service interval specified in your owner's manual. This is often every 100-200 hours or annually. This is the single most effective preventative step. A clogged filter forces the pump to work much harder, drastically shortening its life. If your setup only has the internal tank strainer, ensure it's checked and cleaned during pump replacements. Treat filter replacement as critical.
  • Maintain Adequate Fuel Levels: While you shouldn't ride with a full tank every time, consistently running the tank very low (below 1/4) increases the risk of the pump overheating. Fuel in the tank helps cool the submerged pump motor. Sustained operation near empty also makes the pump suck in settled debris more easily. Try to refill before the gauge drops below the 1/4 mark, especially during demanding rides. Frequent very low-fuel operation significantly accelerates pump wear.
  • Practice Safe Long-Term Storage: If storing your Sportsman 570 for more than 30 days:
    • Add a fuel stabilizer explicitly designed for ethanol fuel. Follow the instructions carefully.
    • Fill the tank to near full (95%). This minimizes airspace inside the tank, reducing moisture condensation and preventing the pump seals from drying out.
  • Avoid Fuel Contamination: Keep the fuel tank cap area clean before opening it to refuel. Don't pour old or questionable fuel from dirty containers into the tank. Use a dedicated, clean gas can for the ATV.
  • Protect Electrical Connections: Regularly inspect the wiring harness leading to the fuel tank connector for damage, chafing against the frame, or signs of corrosion. Ensure the connector at the module cap is fully seated and protected from mud/water ingress. Dielectric grease on connectors helps prevent corrosion.

Conclusion: Ensuring Reliable Fuel Delivery

The fuel pump in your Polaris 570 Sportsman is a critical but relatively simple component. Recognizing the telltale signs of its failure – hard starting, power loss, sputtering, or no-start conditions – empowers you to act quickly. Methodical testing, focusing primarily on fuel pressure measurement and electrical verification, prevents unnecessary part replacements. When a failing pump is confirmed, replacing the entire module assembly following a careful procedure ensures a lasting fix. Most importantly, incorporating routine preventative maintenance like timely filter changes, using clean fuel, and proper storage vastly extends your fuel pump's life, enhancing your Sportsman's reliability and your enjoyment on every trail. Paying attention to this key component means fewer breakdowns and more miles of dependable adventure.

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