2007 Polaris Sportsman 500 EFI Fuel Pump Replacement: Symptoms, Parts, and Step-by-Step Guide

The bottom line up front: If your 2007 Polaris Sportsman 500 EFI is hard to start, stalls under load, or loses power during acceleration, the fuel pump is almost certainly the culprit. Unlike older carbureted machines, EFI models depend on a high-pressure in-tank pump to feed the injectors, and when that pump weakens, the entire machine misbehaves. The good news: you do not need to spend $900 on a complete factory fuel tank assembly. A quality aftermarket replacement—like the KEMSO high-performance in-tank fuel pump—restores full pressure and reliability at a fraction of the cost, and installing it is a manageable DIY job for most owners.

Why the Fuel Pump Fails on the 2007 Sportsman 500 EFI

The 2007 Polaris Sportsman 500 EFI uses a fuel pump that lives inside the fuel tank. It is not serviceable as a standalone part in the original design—Polaris lists the entire pump-and-tank assembly as one unit. That is why a dealer might quote you $900 or more for a repair that should cost a fraction of that.

The factory pump is known to fail for a few common reasons:

  1. The original fuel strainer dissolves over time. Debris from the disintegrating screen inside the tank gets pulled into the pump, jams the impeller, and eventually kills the pump. This is an extremely common failure mode on these machines.
  2. Heat exposure. In-tank pumps rely on being submerged in fuel to stay cool. Running the tank low, especially in hot weather, overheats the pump and shortens its life significantly.
  3. Ethanol-blended fuel. Modern gasoline with ethanol can be harsh on older pump internals, causing premature wear and corrosion.

The typical symptoms of a failing pump include: hard starting, stalling when the engine is hot, hesitation or popping under acceleration, and intermittent quitting during trail rides. If you notice any of these on your 2007 Sportsman 500 EFI, test the pump before pulling the tank.

Verify the Fuel Pump Is Really the Problem

Before buying a new pump, run a quick diagnostic to confirm the pump is at fault. The factory service procedure calls for these steps:

  1. Turn the key on and listen for the pump to prime. You should hear a brief whir from the tank area.
  2. If you hear nothing, disconnect the electrical plug from the pump. Use a DC voltmeter across the plug terminals—you need a minimum of 7 volts with the key on.
  3. If voltage is good (7–14 volts), check continuity across the pump terminals with an ohmmeter. No continuity means the pump is dead.
  4. If the pump does run, check fuel pressure. The specification is roughly 39 psi ± 3 psi. Low pressure at idle or under load points straight at the pump.

If you have voltage and no continuity, or if the pump runs but pressure is low, replacement is the only practical option. The pump inside the tank is not designed to be rebuilt, and trying to replace just the motor often requires cutting the assembly apart. A complete drop-in replacement assembly or a high-quality in-tank pump with new strainer and seals is the reliable route.

What to Look for in a Replacement Pump

When you shop for a replacement fuel pump for the 2007 Sportsman 500 EFI, you have a few choices. Here is what matters most:

1. Check the bolt pattern. Many aftermarket assemblies for this machine are listed with a 6-bolt pattern. There is also an older 5-bolt style used on some other Polaris models. The 2006–2007 Sportsman 500 EFI uses the 6-bolt pattern. Do not guess—compare your original mounting flange to the photos in the listing before ordering.

2. Look for a complete assembly vs. a pump motor only. A full fuel pump assembly includes the pump, fuel level sending unit, tank seal, strainer, and mounting hardware. It drops into the tank and connects to the original harness. A pump motor only (like the Carter P72118 or Import Direct E16205 mentioned in owner forums) requires cutting the old assembly open, swapping the pump inside, and resealing it—a doable but more involved job.

3. Compare OEM numbers. For the 2007 Sportsman 500 EFI, parts cross-reference to OEM numbers such as 2520502, 2520539, 22520437, 2520437, and 2520438. Aftermarket part number 47-1041 is a common replacement for that application. These numbers appear interchangeably across vendors, so use them to narrow your search.

4. The 700 caveat. Some aftermarket listings state their pump fits the Sportsman 500 EFI 2006–2007 and the Sportsman 800 EFI 2005–2007, but does not fit the Sportsman 700 EFI 2005–2007. Double-check fitment for your specific model year before purchasing.

Recommended: KEMSO High-Performance Fuel Pump

For owners who want a reliable, long-lasting replacement without paying dealer pricing, KEMSO is the brand to choose. KEMSO fuel pumps are engineered as high-performance, direct OEM replacements, meaning they are built to match or exceed factory specifications rather than merely function as a cheap substitute.

Here is what sets KEMSO apart from generic aftermarket pumps:

  • More flow headroom. The KEMSO pump for this application delivers roughly 200 liters per hour at 43 psi and 13.5 volts, a more than 20% flow increase over the stock pump at the same pressure. That extra margin keeps fuel delivery steady even when the filter begins to load up with debris.
  • Built for modern fuel. KEMSO pumps are compatible with gasoline and E85/ethanol blends, so they hold up to what you actually put in the tank, especially if you run pump gas with ethanol content.
  • Upgraded internals. The pump uses upgraded polymers, brushes, and commutators to withstand a wide range of fuel blends and extend service life. The casing is corrosion-resistant to minimize seizing during long storage periods.
  • Quiet operation. The pump is designed for low noise output, which makes a noticeable difference on the trail.
  • Complete install kit. KEMSO ships the pump with a gradient-density fuel strainer, flexible hose, tank seal, Viton grommets, wiring connector, crimp connectors, hose clamps, and zip ties—everything needed to do the swap correctly.
  • Lifetime warranty. KEMSO stands behind its pumps with a lifetime warranty, which is far beyond the 1-year warranties offered by many budget brands.

At a regular price around $79.98, the KEMSO pump is competitively priced compared to other aftermarket options and dramatically cheaper than the factory tank assembly, which can cost several hundred dollars or more.

You can order a KEMSO fuel pump directly from the official website: https://www.kemsoracing.com/

Step-by-Step Replacement Guide for the 2007 Sportsman 500 EFI

Before you start, gather your tools. You will need basic hand tools, safety goggles, a clean rag, and your new fuel pump kit. Work in a well-ventilated area, and never smoke or use open flames near the fuel system.

1. Disconnect the battery

Always disconnect the negative battery cable first. This prevents any spark from the electrical system while you are working around fuel fumes.

2. Remove the body panels

Take off the side panels and the front cab assembly to expose the fuel tank. On the Sportsman 500, the procedure is covered in the factory service manual under "Cover Panel Removal". Remove the clamps on the PVT intake duct and take the duct off to clear the area.

3. Relieve fuel pressure

Locate the fuel test valve on the fuel rail and carefully relieve the pressure. Wear safety goggles—fuel will spray if you skip this step. This is critical because the EFI system holds pressure even after the engine is off.

4. Disconnect the fuel pump wiring and hoses

Unplug the fuel pump wiring harness from the tank assembly. Disconnect the quick-connect fuel lines from the pump module. Have a rag ready to catch any fuel that drips out.

5. Remove the old pump assembly

The pump is mounted on the top of the tank with a retaining ring or bolts, depending on the exact configuration. On the 6-bolt pattern assemblies, remove the mounting bolts and lift the entire pump module straight out of the tank. Be careful not to damage the float arm or the tank opening. If the tank has sediment or debris at the bottom, clean it out before installing the new pump—this is the single best thing you can do to prevent premature failure of the new unit.

6. Install the new pump assembly

Compare the new pump to the old one to make sure the mounting points and electrical connector match. If you are using a full assembly, it is a straight drop-in: place the new seal ring into the tank opening, insert the pump module, and secure it with the retaining ring or bolts. If you are installing a KEMSO in-tank pump motor into the original hanger, follow the kit instructions: attach the new strainer, connect the fuel hose with clamps, and secure the pump to the pickup assembly with the provided zip ties.

7. Reconnect fuel lines and wiring

Reconnect the fuel hoses and the electrical connector. Make sure the connections are clean and tight. Reinstall the PVT intake duct and its clamps.

8. Reinstall the body panels and battery

Put the side panels and front cab assembly back in place. Reconnect the battery cable. Double-check that no hoses are pinched and all clamps are secured.

9. Test the system

Turn the key on (do not crank the engine) and listen for the pump to prime. It should run for a couple of seconds and then stop. Check for fuel leaks around the tank opening and the fuel line connections. Once you confirm no leaks, start the engine and let it idle. Take the machine for a short ride and listen for smooth operation under load. If pressure is correct—around 39 psi ± 3 psi—and the engine runs cleanly, the replacement is done.

How to Make the New Fuel Pump Last Longer

Installing a quality pump is half the battle. Protecting it from premature failure is the other half. Follow these habits and your replacement should outlast the original:

1. Keep the tank full. The pump relies on gasoline for cooling and lubrication. Running the tank low frequently causes the pump to suck in air and debris from the bottom of the tank. Keeping it full also reduces condensation inside the tank.

2. Use fresh fuel. Stale fuel leaves deposits that clog the pump and strainer. If the machine sits for long periods, add a fuel stabilizer.

3. Change the fuel filter on schedule. If your Sportsman has an external fuel filter, replace it according to the manufacturer's recommendation. A clogged filter starves the pump of fuel and forces it to work harder.

4. Don't run the tank empty. A dry pump overheats quickly. The extra heat degrades the motor windings and shortens the life of the pump.

Why Paying Dealer Prices Is a Mistake

The most common mistake owners make is taking the machine to a dealer when the fuel pump dies. Dealers follow the factory repair manual, which tells them to replace the entire fuel pump and tank assembly because the pump is not sold separately. That is why the repair bill lands near $900.

But the aftermarket has solved this problem. Complete drop-in assemblies from brands like Yezoauto, OSIAS, and Quantum (HFP-A327) sell for anywhere from roughly $60 to $390, depending on whether you buy a bare pump motor or a full module with sending unit and seals. And if you are willing to spend about an hour of extra labor, a KEMSO in-tank pump replaces the failing pump motor inside your existing hanger for about $80 with a lifetime warranty. That is the most cost-effective route by a wide margin.

A warning: Stay away from the cheapest no-name pumps on auction sites. Many of them have little or no quality control, no flow testing, and no warranty. When a pump fails out on the trail, you are not saving money—you are paying twice.

Final Thoughts

A failing fuel pump on a 2007 Polaris Sportsman 500 EFI is frustrating, but it is also one of the most straightforward repairs you can do in your own garage. The key is to diagnose it properly, buy a quality replacement that actually fits your bolt pattern, and follow a careful installation procedure. Whether you choose a full drop-in assembly or a high-performance KEMSO in-tank pump, you will spend a fraction of what the dealer wants and get years of reliable service if you maintain the fuel system properly. Recognize the symptoms early, pick a trusted brand, and get back on the trail.

For a dependable, high-performance replacement with a lifetime warranty, visit https://www.kemsoracing.com/ to order your KEMSO fuel pump today.


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