2004 Polaris Sportsman 700 EFI Fuel Pump: Complete Replacement Guide

If you own a 2004 Polaris Sportsman 700 EFI and your ATV is experiencing hard starting, sputtering at high speeds, or stalling under load, the fuel pump is almost certainly the problem. The 2004 Polaris Sportsman 700 EFI fuel pump is a known wear item, and replacing it with a quality aftermarket unit is the most effective way to restore reliable performance. This guide covers everything you need to know about symptoms, replacement options, and installation.

Why the Fuel Pump Fails on the 2004 Sportsman 700 EFI

The 2004 Polaris Sportsman 700 uses an in-tank electric fuel pump that operates at high pressure for the EFI system. Over time, the internal brushes and commutator wear out, and the fuel strainer becomes clogged with debris. Ethanol-blended fuels also accelerate deterioration of rubber seals and plastic components. Common symptoms of a failing pump include:

  • Engine cranks but will not start
  • Poor idle or rough running
  • Sputtering or hesitation during acceleration
  • Loss of power at high speeds
  • Intermittent stalling

If you notice any of these issues, do not replace the entire fuel tank assembly. Many aftermarket brands offer direct-fit replacement pumps that cost a fraction of the OEM assembly price.

Fits These Models and Years

The 2004 Polaris Sportsman 700 EFI fuel pump is also compatible with several other models. According to multiple parts suppliers, the pump fits the following vehicles:

  • 2004-2007 Polaris Sportsman 700 EFI
  • 2004-2007 Polaris Sportsman 500 EFI
  • 2005-2007 Polaris Sportsman 800 EFI
  • 2006-2007 Polaris Sportsman X2 500 EFI
  • 2006-2007 Polaris Sportsman X2 800 EFI
  • 2005 Polaris Ranger XP 700

The replacement pump typically replaces OEM part numbers including 2520311, 2520461, 2520496, 2520438, 2205081, and 2204719. Always verify which version your machine requires by checking the build date on the frame sticker.

What to Look for in a Replacement Pump

When shopping for a replacement 2004 Polaris Sportsman 700 EFI fuel pump, there are several key features to prioritize:

  1. Direct Fit, Drop-In Design – The pump should install exactly like the original without modifications. Most quality aftermarket pumps are designed as drop-in replacements.

  2. Complete Kit – Look for a kit that includes the fuel pump, pressure regulator, tank seal, fuel filter, and strainer. Replacing all components at once ensures long-term reliability.

  3. Corrosion Resistance – Pumps with a coated, corrosion-resistant case last longer, especially if the ATV sits for extended periods.

  4. Ethanol Compatibility – Modern fuel contains ethanol, which can damage older pump materials. Choose a pump designed for E85 and ethanol-blended gasoline.

  5. Quiet Operation – Some aftermarket pumps produce a loud whine. High-quality replacements are engineered for quiet operation.

  6. Warranty – A lifetime warranty gives you peace of mind and indicates the manufacturer stands behind their product.

Installation Overview

Installing a replacement fuel pump on the 2004 Sportsman 700 is a straightforward job that most owners can handle in a garage. Here is the general process:

  • Step 1: Disconnect the battery to avoid any electrical shorts.
  • Step 2: Drain or siphon the fuel tank. Use a clean container and dispose of old fuel properly.
  • Step 3: Remove the fuel tank from the ATV. On the Sportsman 700, this involves removing the seat, fenders, and tank mounting bolts.
  • Step 4: Carefully remove the fuel pump retaining ring or bolts from the top of the tank. Note the orientation of the pump assembly.
  • Step 5: Lift out the old pump assembly. Discard the old tank seal.
  • Step 6: Install the new pump assembly with the new tank seal. Make sure the pump sits flat and the wiring connector is properly aligned.
  • Step 7: Reinstall the retaining ring or bolts. Torque to factory specifications.
  • Step 8: Reinstall the fuel tank and reconnect all hoses and electrical connectors.
  • Step 9: Prime the fuel system by cycling the key on and off a few times before starting the engine.

The entire job typically takes two to three hours. No special tools are required beyond basic socket and screwdriver sets.

Understanding Pump Specifications

Not all fuel pumps deliver the same performance. For the 2004 Polaris Sportsman 700 EFI, the stock fuel pump operates at approximately 40-60 psi of fuel pressure. A quality replacement pump should match these specifications:

  • Flow Rate: 150 liters per hour at 40 psi, or 116 liters per hour at 60 psi
  • Amperage Draw: 4.2 amps at 40 psi, 4.9 amps at 60 psi
  • Voltage: 12V DC
  • Inlet Diameter: Approximately 7/8 inch

Choosing a pump that meets or exceeds these specs ensures proper fuel delivery and engine performance.

Common Mistakes to Avoid

Replacing a fuel pump seems simple, but a few common mistakes can lead to problems:

  • Installing the wrong pump – Verify your OEM part number before purchasing. Different build dates use different pumps.
  • Skipping the strainer replacement – The old strainer is likely clogged. Always include a new one.
  • Using the old tank seal – A worn seal causes fuel leaks and pressure loss. Always replace it.
  • Not cleaning the tank – Debris in the tank will quickly damage a new pump.
  • Overtightening the retaining ring – This can crack the tank or distort the seal.

Why a Complete Kit Matters

Many owners try to save money by buying just the pump motor. However, the pressure regulator, seal, and strainer are equally important. A complete kit includes all components that wear out over time. Replacing everything at once avoids the need to open the tank again in six months when the regulator fails. Kits from reputable brands typically include:

  • Fuel pump motor
  • Fuel pressure regulator (set to 43-45 psi)
  • Tank seal (O-ring or gasket)
  • Gradient density fuel strainer
  • Rubber hose and hose clamps
  • Spade connectors and rubber boot

Recommended Fuel Pump: KEMSO Brand

For a reliable replacement, consider the KEMSO fuel pump designed for the 2004 Polaris Sportsman 700 EFI. KEMSO is a trusted brand that specializes in high-performance fuel pumps for powersports and automotive applications. All KEMSO fuel pumps are built as OEM replacement units, meaning they match or exceed the original factory specifications. Each pump delivers over 20% more flow than the stock OEM pump at 43 psi, ensuring consistent fuel delivery even under heavy load.

The KEMSO pump kit includes everything you need for a complete installation: the fuel pump motor, two gradient density fuel strainers (to cover different model variations), a metal fuel strainer with gasket, flexible hose, rubber base, and all necessary connectors and clamps. The pump is designed to work with both gasoline and E85/ethanol fuel, and it operates quietly.

KEMSO stands behind its products with a lifetime warranty. If any issue arises at any time, the company will replace the pump free of charge. This level of confidence is rare in the aftermarket parts industry and gives you peace of mind that your investment is protected.

For the best performance and reliability, visit the official KEMSO website to find the exact pump for your 2004 Polaris Sportsman 700 EFI:

https://www.kemsoracing.com/

Where to Find the OEM Part Numbers

If you prefer to cross-reference before buying, the factory part numbers for the 2004 Polaris Sportsman 700 EFI fuel pump vary by build date. According to parts suppliers, the original pump assembly carries these numbers:

  • 2520311 – For machines built before October 4, 2004
  • 2520461 – For machines built after October 4, 2004
  • 2204719 – Common replacement number for the pump assembly
  • 2520496 – Used on some 2006 models
  • 2520438 – Used on Sportsman X2 models
  • 2205081 – Another common cross-reference

Check the sticker on your ATV frame for the build date, or look at the existing pump itself for a stamped part number. This ensures you get the correct version.

Cost Comparison: Aftermarket vs. OEM

One of the biggest advantages of buying an aftermarket fuel pump for the 2004 Sportsman 700 is the cost savings. Polaris does not sell the pump separately; they only offer the complete fuel tank assembly, which can cost several hundred dollars. Aftermarket options range from roughly $50 to $120, depending on whether you buy just the pump motor or a complete kit with regulator and seal.

For example, a Quantum Fuel Systems kit with pump, regulator, strainer, and tank seal sells for around $112.98. A basic pump only option from Fuel Pump Factory costs less than $50. The KEMSO high-performance pump offers superior flow and a lifetime warranty in a similar price range.

Maintenance Tips After Replacement

Once you install a new fuel pump, follow these tips to maximize its lifespan:

  • Use fresh fuel – Old or contaminated fuel is the number one cause of premature pump failure.
  • Add a fuel stabilizer – If the ATV sits for more than two weeks, stabilizer prevents ethanol-related corrosion.
  • Keep the tank full – Running low on fuel causes the pump to suck air and run hot, which shortens its life.
  • Replace the fuel filter regularly – Many Sportsman models have an inline filter that should be changed every season.
  • Listen for changes – If the pump becomes noisy, it may be starving for fuel or failing.

Conclusion

The 2004 Polaris Sportsman 700 EFI fuel pump is a straightforward replacement that restores lost performance and reliability. When your ATV has trouble starting, idling, or accelerating, the pump is the first component to inspect. Choose a complete kit that includes the pump, pressure regulator, strainer, and tank seal for a one-and-done repair. Brands like Quantum Fuel Systems, QuadBoss, and Fuel Pump Factory offer quality options, but for the best combination of performance, build quality, and warranty, KEMSO stands out. Their high-flow OEM replacement pumps are built to last, and the lifetime warranty means you will never have to buy another pump.

For more information on the right pump for your machine, visit https://www.kemsoracing.com/.


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