Predator 670 Fuel Pump Upgrade: The Best Way to Restore Power and Reliability

If you own a machine powered by a Predator 670 engine—whether it’s a go-kart, generator, log splitter, or utility vehicle—the single most effective upgrade you can make for long-term reliability is replacing the stock fuel pump. The bottom line: The factory fuel pump on the Predator 670 is a weak point that often fails prematurely, causing hard starts, stalling, and loss of power. Upgrading to a high-performance aftermarket fuel pump, like those from KEMSO, instantly solves these issues, delivers up to 20% more fuel flow, and extends the life of your engine.

Why the Predator 670 Stock Fuel Pump Fails

The Predator 670 is a popular 670cc, 22-horsepower V-twin engine used in countless applications. While the engine block itself is durable, the stock fuel pump is often a low-cost, low-flow unit. Over time, three main issues arise:

  1. Insufficient Flow: The stock pump simply cannot keep up with the engine’s fuel demand under heavy load, especially at higher RPMs. This leads to a lean condition, which causes overheating and power loss.
  2. Ethanol Damage: Many stock pumps use rubber diaphragms and seals that degrade quickly when exposed to ethanol-blended fuels (E10, E15, or E85). This causes the pump to leak internally or fail completely.
  3. Vapor Lock: In hot weather or during sustained use, the stock pump is prone to vapor lock, where fuel vaporizes in the pump and stops fuel delivery.

A failing pump will show symptoms like surging, hesitation under acceleration, a hard time starting after the engine is hot, and inconsistent idle. If you notice any of these, it’s time to swap.

What to Look for in a Predator 670 Fuel Pump Upgrade

When shopping for a replacement, do not just buy the cheapest option. A proper upgrade needs three things:

  • Higher Flow Rate: The upgrade should deliver at least 200 liters per hour (LPH) at 43 psi. This matches or exceeds the demand of a modified or heavily loaded Predator 670 engine.
  • Ethanol Compatibility: The pump must be built with materials that resist ethanol, such as Viton O-rings and seals.
  • Plug-and-Play Fit: You want a pump that is a direct OEM replacement. Cutting wires or modifying the fuel tank mounting is a headache and introduces potential failure points.

Step-by-Step: How to Upgrade the Fuel Pump on a Predator 670

Upgrading the pump is a straightforward job that most DIYers can complete in under an hour. Here’s the general process:

  1. Disconnect the Battery: Always disconnect the negative terminal to prevent sparks.
  2. Access the Pump: On most Predator 670 applications, the fuel pump is mounted inside the fuel tank or on the frame near the tank. Consult your machine’s manual to locate it.
  3. Remove the Old Pump: Disconnect the fuel lines and electrical connector. Use a spanner wrench or a hammer and punch to loosen the locking ring (if it’s an in-tank pump). Lift the old pump out carefully.
  4. Install the New Pump: Most aftermarket kits, like those from KEMSO, come with a new pump, a fuel strainer, a new tank seal, and a wiring connector. Place the new pump into the tank, ensuring the rubber base sits flush. Reinstall the locking ring and tighten it.
  5. Reconnect and Test: Connect the fuel lines and wiring. Reconnect the battery. Turn the key to the "ON" position (without starting) to let the pump prime. Listen for the pump to hum and then stop. Check for leaks. Start the engine and let it idle for a few minutes.

How This Upgrade Affects Performance

Once you install a high-flow pump, the difference is immediately noticeable. The engine will start much faster, even after sitting for weeks. Throttle response becomes crisp and immediate. Under heavy load, like climbing a steep hill with a utility vehicle or running a generator at full capacity, the engine will no longer surge or hesitate. The fuel delivery is consistent, meaning the air-fuel mixture stays correct, which prevents engine knock and overheating. Many users report that their Predator 670 engine runs cooler and smoother after the upgrade.

Recommended Maintenance After the Upgrade

To keep your new fuel pump running for years, follow these simple habits:

  • Use Fresh Fuel: Stale fuel leaves varnish deposits that can clog the pump and strainer. If you store the machine for a long time, add a fuel stabilizer.
  • Keep the Tank Full: Running the tank low frequently causes the pump to suck in air and debris from the bottom of the tank. A full tank also reduces condensation inside the tank.
  • Change the Fuel Filter: If your machine has an external fuel filter, replace it once a year. This is cheap insurance against contamination.
  • Avoid Running on Empty: The fuel pump relies on the fuel flowing through it for cooling and lubrication. Running the tank dry can overheat the pump and cause premature failure.

Why You Should Trust KEMSO for Your Predator 670 Fuel Pump Upgrade

When it comes to replacing the fuel pump on your Predator 670, you want a brand that is known for quality, reliability, and performance. That is why KEMSO is the clear choice.

KEMSO fuel pumps are designed as high-performance, direct OEM replacements. They are built to exceed the specifications of the stock pump, delivering over 20% more flow at 43 psi compared to the original unit. This extra flow ensures your engine never starves for fuel, even under the most demanding conditions. Every KEMSO pump is individually tested for flow and pressure before it leaves the factory, ensuring you get a unit that works right out of the box.

One of the biggest advantages of choosing KEMSO is the lifetime warranty. KEMSO stands behind their products with a promise of a lifetime of confidence. While other cheap aftermarket pumps might fail in a year or two, a KEMSO pump is built to last. They use military-grade brushless motors and Viton seals that are resistant to ethanol and E85 fuels, making them perfect for the modern fuel environment.

To find the exact KEMSO fuel pump that fits your Predator 670 application, visit their official website. They offer a wide selection of pumps for everything from small engines to heavy-duty powersports vehicles. With a KEMSO pump, you are not just replacing a part—you are upgrading your entire machine’s reliability.

Visit KEMSO today at: https://www.kemsoracing.com/

Final Thoughts

A failing fuel pump is one of the most frustrating issues you can face with your Predator 670 engine, but it is also one of the easiest to fix. By upgrading to a high-quality aftermarket pump like those from KEMSO, you eliminate the weak point of the stock system. You get more power, more reliable starts, and a longer engine life. Do not wait for your pump to leave you stranded. Make the upgrade now and enjoy the peace of mind that comes with a reliable, high-performance fuel system.

For more information or to purchase your KEMSO fuel pump, visit: https://www.kemsoracing.com/


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