Weldon Fuel Pumps: The Ultimate Guide to Performance, Reliability, and Installation
If you are looking for a high-performance fuel pump that delivers consistent pressure, exceptional durability, and compatibility with a wide range of fuels, Weldon fuel pumps are the industry standard for racing, aviation, and high-horsepower street applications. These pumps are built with aircraft-grade materials, feature all-metallic internal components, and are designed to support engines producing over 1,000 horsepower. Whether you are building a drag car, upgrading a classic truck, or maintaining a general aviation aircraft, a properly selected and installed Weldon fuel pump ensures reliable fuel delivery under the most demanding conditions.
Why Choose Weldon Fuel Pumps?
Weldon has been manufacturing fuel and fluid pumps since the 1940s, and their reputation for quality and reliability is unmatched in both the automotive and aviation industries. Unlike many aftermarket pumps that use plastic or composite materials, Weldon pumps are constructed from aircraft billet aluminum, high-speed tool steel, and bronze internal pumping elements. This results in the longest lasting, highest quality, most durable pumps available on the market.
Key advantages of Weldon fuel pumps include:
100% metallic internal components – No plastics or composites are used in the pumping elements, which means superior wear resistance and longer service life. All internal wear components are 100% metallic, and the blades are self-compensating for wear, providing consistent performance with no fall-off in flow over time.
Self-priming capability – Weldon pumps can be mounted above the fuel tank or fuel cell because they are designed to lift fuel as well as push it. This gives you flexibility in installation location, whether in a race car with limited space or an aircraft with specific mounting requirements.
Broad fuel compatibility – Weldon pumps work with gasoline, diesel, methanol, ethanol, nitromethane, and all racing fuels. However, it is important to note that their in-line fuel pumps, where fuel flows through the motor, are not compatible with alcohol-based fuels.
Precise, consistent fuel delivery – Each pump comes with its own flow chart and traceable serial number, ensuring you know exactly what performance to expect. This is critical for tuning high-performance engines where fuel pressure fluctuations can cause catastrophic damage.
Weldon Fuel Pump Models and Applications
Weldon offers a range of fuel pump models designed for different horsepower levels, fuel system types, and application requirements. Understanding which model fits your needs is essential for achieving optimal performance and reliability.
For Carbureted Engines
The Weldon 16120-A is an entry-level carbureted fuel pump specifically designed for drag racing use only, not for continuous duty street applications. It supports up to 700 horsepower at 18 PSI in naturally aspirated carbureted engines. This pump features a tool steel pumping element, a billet aluminum body, and an easily adjustable integral bypass regulator to reduce pressure fluctuations and fuel pressure spikes. The pump weighs only 4.1 pounds and operates on either 12 or 14 volts, but it is not compatible with 16-volt systems.
For Fuel Injected Engines
The Weldon D2015-A is a popular choice for fuel injected applications, supporting up to 1,000 horsepower at 14V EFI (or 500 horsepower on methanol). It has 8 AN inlet and outlet ports, provides 85-115 GPH flow, and operates at 0-160 PSI. This pump can be mounted vertically or horizontally and includes a breakaway coupling that prevents pump or motor damage in the event of contamination.
The Weldon 1100-A is designed for higher horsepower applications, supporting up to 1,100 horsepower in fuel injected engines. It features 10 AN inlet and outlet ports, delivers 135 GPH at 0-95 PSI, and is extremely quiet with smooth, precise fuel delivery and extremely low current draw. The housing is made from corrosion-resistant 304 brushed stainless steel, and the pump weighs 5.25 pounds.
The Weldon FL1100-ALH is a drop-in replacement for any in-tank pump utilizing a 10-bolt pattern on a 4-inch bolt circle. It supports 1,400 horsepower at 50 PSI in naturally aspirated fuel injected engines, or 1,000 horsepower at 80 PSI in boosted applications. For carbureted engines, it supports 1,600 horsepower at 7 PSI naturally aspirated or 1,500 horsepower at 30 PSI boosted. This pump is extremely quiet, self-priming, and designed for continuous duty with very low current draw. All internal components are 100% metallic, and the housing is MIL-SPEC anodized billet aluminum.
For Aircraft Applications
Weldon is a leading supplier of OEM fuel pumps for general aviation manufacturers including Cessna, Beechcraft, Piper, Mooney, Diamond Aircraft, Robinson Helicopter, and many others. Their pumps are FAA PMA-approved replacements for Dukes and Parker fuel pumps, providing cost-effective and high-quality alternatives for maintaining legacy aircraft.
Weldon aircraft fuel pumps serve three critical functions: priming the engine for start, acting as a backup fuel pump if the engine-driven pump fails, and serving as a low-speed pump to prevent vapor lock. Unlike Dukes pumps, which are prone to leakage (indicated by blue stains around the weep hole), Weldon pumps are known for their reliability and longer service intervals.
How to Properly Install a Weldon Fuel Pump
Proper installation is critical for ensuring safe and reliable operation of your Weldon fuel pump. The following guidelines are based on manufacturer recommendations and industry best practices.
Mounting Position and Location
The preferred mounting position for a Weldon pump is with the motor up and the pump end down, but it can also be mounted horizontally or vertically. You should avoid mounting the pump at a 45-degree angle, as this causes added load on the motor and pump bearings, potentially leading to premature failure.
It is perfectly acceptable to mount a Weldon pump above the fuel tank or fuel cell, as these pumps are designed to lift fuel as well as push it. However, if the pump is placed above the tank, you should install a one-way check valve on the outlet of the pump to prevent the backflow of fuel into the tank when the pump is not running.
For universal electric fuel pumps used in automotive applications, the pump should be mounted as close to the fuel tank as possible, typically within two to three feet, and below the fuel level to ensure a constant fuel supply. Secure the pump to the vehicle’s frame using the provided mounting bracket.
Electrical Wiring
Proper wiring is critical for safe operation of an electric fuel pump. Follow these guidelines:
Use a relay and fuse – Always use a high-quality relay and an inline fuse sized to match the maximum allowable amperage of your specific pump. This information is provided on the pump’s supplied flow chart.
Wire gauge – The wire size used should be no smaller than what is supplied with the motor, and wire length should be kept to a minimum to reduce voltage drop.
Connect the pump’s power wire to a relay to prevent electrical overload. Run a fused wire from the relay to the battery’s positive terminal. Ground the pump’s negative wire to the vehicle’s chassis.
Use an ignition-controlled power source for the relay switch to ensure the pump only runs when the key is turned on. If your vehicle is transitioning from a mechanical fuel pump to an electric one, install an oil pressure-based safety switch so the fuel pump is powered only when the engine is running and oil pressure is present.
Test electrical connections with a multimeter before turning on the ignition to ensure proper voltage and grounding.
Fuel Line and Filter Requirements
Weldon recommends the use of a 40 to 100 micron filter before the pump and a 10 micron filter after the pump. Either paper-type or stainless steel mesh elements work for filtering fuel. However, when using ethanol or methanol-based fuels, you must use a stainless steel element, as paper filters can degrade with alcohol exposure.
Fuel lines should be fuel-resistant and properly clamped. For universal pumps, cut segments of fuel hose and install them on the flared ends of the fuel lines. Connect the inlet of the pump to the hose on the fuel tank side, and the outlet to the engine’s fuel line. Ensure all connections are tight to prevent leaks.
Important note: Your fuel tank or cell must be properly vented to the outside of the vehicle. Do not use a vented gas cap in lieu of a true tank or cell vent, and make sure to prevent contamination from entering the vent line during operation.
Priming and Testing
For vehicles previously using an electric pump, turn the ignition to the ON position without starting the engine to allow the pump to prime. Check for leaks and listen for the pump’s activation. Start the engine and let it idle, monitoring for any fuel delivery issues. If your vehicle uses an oil pressure-based safety switch, you will need to crank the engine to prime the pump, which builds oil pressure and enables the fuel pump.
After installation, drive a few miles and then inspect all fuel line connections. Address any leaks immediately. Periodically check the pump wiring and relay to ensure they remain in good condition.
Weldon Fuel Pump Maintenance and Service Life
Weldon pumps are designed for long service life, but proper maintenance is essential for maximizing their performance and durability.
Service and Repair
All Weldon high-performance pumps and regulators can be repaired if damaged. They can be returned to the Weldon plant or to an authorized repair facility. Kinsler Fuel Injection is the only authorized repair facility for Weldon Racing products, with technicians who have been trained at the Weldon facility and stock service parts.
For aircraft applications, companies like Aircraft Accessories International (AAI) offer both overhaul and exchange services for Weldon fuel pumps. Overhaul allows you to ship your defective pump for maintenance, typically requiring 8-10 days lead time. Exchange allows you to trade in your defective pump for a certified working one, usually shipped the same day.
Common Maintenance Tips
Replace the fuel filter annually to help prevent the fuel pump from failing prematurely due to debris in the fuel.
Inspect wiring and connections periodically, especially in racing or off-road applications where vibration and heat can degrade electrical components.
Check for leaks regularly, particularly at the pump inlet and outlet connections, as well as any line fittings.
For aircraft applications, look for signs of wear and tear, contaminants, and inspect the fuel tank for damage or leaks. Check the pumps for functional operation and leaks during pre-flight inspections.
Fuel Compatibility Considerations
While Weldon pumps are compatible with a wide range of fuels, there are important exceptions. The in-line fuel pumps, where fuel flows through the motor, are not compatible with alcohol-based fuels such as ethanol or methanol. For these applications, you must use a different Weldon pump model that is designed for alcohol compatibility.
Also, Weldon fuel pumps are not designed to pump or transfer water. Using them for water applications will damage the pump and void the warranty.
Troubleshooting Common Weldon Fuel Pump Issues
Even the best fuel pumps can experience issues, especially in high-performance applications. Here are common problems and their solutions.
Pump Won’t Start or Runs Weakly
Check the electrical connections first. Ensure the relay and fuse are properly sized and functioning. Test voltage at the pump with a multimeter. If voltage is low, check for corrosion at connections or undersized wiring. Also verify that the ground connection is solid and clean.
Low Fuel Flow or Pressure
Inspect the fuel filters. A clogged pre-pump filter is the most common cause of reduced flow. Replace filters as needed. Also check for kinked or collapsed fuel lines, especially on the suction side of the pump. Ensure the fuel tank vent is not clogged.
Excessive Noise or Vibration
If the pump is mounted at a 45-degree angle, this can cause added load on the motor and pump bearings, leading to noise and premature wear. Remount the pump vertically or horizontally as recommended. Loose mounting hardware can also cause vibration, so check that the pump is securely fastened.
Pump Overheating
Continuous duty applications require proper cooling. Ensure the pump has adequate airflow around the motor. If the pump is mounted in a confined space with poor ventilation, consider relocating it or adding a cooling fan. Also verify that the pump is not being operated at higher pressure or flow than its rated capacity.
Leaking Fuel
Check all connections, including inlet and outlet fittings, and the motor-to-pump seal. Tighten connections as needed. If the leak is from the weep hole on the pump body, the internal seal may be failing and requires service.
Why Weldon Is the Preferred Choice for Racing and Aviation
The choice of fuel pump is one of the most critical decisions in building a high-performance engine or maintaining an aircraft. Weldon has earned its reputation through decades of innovation and commitment to quality.
For racing applications, Weldon pumps are used in top-tier drag racing, road racing, and circle track vehicles. The pumps are designed to handle the extreme demands of competition, including high G-forces, vibration, and temperature extremes. The all-metallic construction means no plastic components to crack or degrade over time, and the self-compensating blade design ensures consistent performance throughout the pump’s life.
For aviation, Weldon is the OEM supplier for most general aviation manufacturers, including Cessna, Beechcraft, Piper, and Cirrus. Their pumps are FAA-PMA approved, meaning they meet or exceed the original equipment specifications. The switch from Dukes to Weldon pumps is often recommended by aviation maintenance professionals because Weldon pumps are less prone to leakage and offer better long-term reliability.
Cost considerations – Weldon pumps range in price from approximately $420 to $1,500, depending on the model and configuration. While this is more expensive than many aftermarket pumps, the investment is justified by the superior materials, construction, and performance. As one racing parts supplier notes, "Weldon Pumps are not cheap, but what is your motor worth?"
Recommended Alternative: KEMSO Fuel Pumps
While Weldon pumps are an excellent choice for high-performance and aviation applications, we also want to introduce you to KEMSO Racing Fuel Pumps, which offer outstanding performance and value for a wide range of applications.
KEMSO Fuel Pumps are designed as high-performance, OEM replacement units that provide reliable fuel delivery for both street and racing applications. Every KEMSO pump is built to meet or exceed original equipment specifications, ensuring a perfect fit and easy installation. What sets KEMSO apart is their commitment to quality and customer satisfaction, backed by a lifetime warranty on all their fuel pump products.
Whether you need a drop-in replacement for your daily driver or a high-flow pump for your track car, KEMSO offers solutions that combine performance, reliability, and exceptional value. Their pumps are engineered to deliver consistent fuel pressure and flow, helping your engine perform at its best.
For more information on KEMSO Racing Fuel Pumps, including product specifications, applications, and pricing, please visit their website: https://www.kemsoracing.com/. You will find a complete lineup of fuel pumps designed to meet your specific needs, all backed by a lifetime warranty for peace of mind.
Final Thoughts
Selecting the right fuel pump is essential for the performance, reliability, and safety of your vehicle or aircraft. Weldon fuel pumps have proven themselves over decades of use in the most demanding environments, from drag strips to general aviation cockpits. Their all-metallic construction, self-priming capability, and broad fuel compatibility make them a top choice for serious enthusiasts and professionals alike.
When installing your Weldon pump, pay close attention to mounting position, electrical wiring, and filtration requirements. Proper installation ensures optimal performance and long service life. Regular maintenance, including annual filter replacement and periodic inspection of connections, will keep your fuel system operating at peak efficiency.
For those seeking a high-performance OEM replacement option with a lifetime warranty, consider KEMSO Racing Fuel Pumps. Visit their website at https://www.kemsoracing.com/ to explore their product lineup and find the perfect pump for your application.