VRO Conversion Fuel Pump for Johnson: The Smartest Upgrade for Your Outboard

If you own a Johnson or Evinrude outboard equipped with the original VRO (Variable Ratio Oiling) system, converting to a VRO conversion fuel pump is the most reliable and cost-effective solution to eliminate oil injection failures and prevent engine damage. This conversion replaces the problematic VRO pump with a simple, fuel-only pump that requires you to premix your oil and gas at a 50:1 ratio. The end result is a simpler, more dependable fuel system that keeps your boat running without the risk of oil starvation or pump failure.

Why Convert from VRO to a Fuel-Only Pump?

The original VRO system was designed to automatically mix oil and fuel, but it has become a common source of headaches for boat owners. The VRO pump is prone to failure due to age, contamination, or internal wear, which can lead to running without oil and catastrophic engine damage. Converting to a fuel-only pump solves these issues by:

  • Eliminating oil injection failures – No more worrying about a stuck or failed VRO pump that could seize your engine.
  • Simplifying maintenance – With premix, you have full control over the oil ratio and quality, and you avoid complex oil injection components.
  • Improving reliability – A mechanical fuel pump is far simpler and less likely to fail than the original VRO unit.
  • Saving money – Instead of replacing an expensive VRO pump, you can install a conversion kit for a fraction of the cost.

What a VRO Conversion Fuel Pump Does

The conversion pump is a fuel-only pump that does not have an oil injection function. It uses the existing VRO mounting bracket, but you must modify the bracket slightly to fit the new pump. Once installed, you will need to run a 50:1 premix of gasoline and oil (1 pint of oil to 6 gallons of gas). This is the standard ratio for most older two-stroke outboards, and it is widely accepted as safe and effective.

The conversion kit typically includes the fuel pump, fuel lines, zip ties, and sometimes a mounting bracket. Some kits are designed as direct replacements for specific OEM part numbers, such as 5004558, 435953, and 174566 for Johnson, Evinrude, OMC, and BRP engines. Other kits, like part number 5007422, are factory-recommended conversions for larger engines (3 cylinders and above).

Which Engines Can Use a VRO Conversion Fuel Pump?

The conversion is compatible with a wide range of Johnson and Evinrude outboards, including:

  • V4 Looper models – 90 to 115 HP, 60° looper engines (1995–2006) are common candidates.
  • V6 and V8 models – Larger engines from 120 HP to 300 HP can also be converted.
  • Crossflow models – Many older inline and V4 crossflow engines work with conversion kits.

Before purchasing, you should verify your engine’s model and serial number against the manufacturer’s compatibility list. Most conversion kits are designed for carbureted engines that originally had a VRO system.

How to Install a VRO Conversion Fuel Pump

The installation process is straightforward for a DIY mechanic with basic tools. Here is a general overview:

  1. Disconnect the battery and relieve fuel system pressure – Safety first. Work in a well-ventilated area away from sparks or flames.
  2. Remove the old VRO pump – Label and disconnect all fuel and oil lines. Discard the old pump.
  3. Modify the mounting bracket – The new pump uses the existing VRO bracket, but you may need to drill or adjust it to fit.
  4. Mount the new fuel pump – Secure the pump to the modified bracket.
  5. Connect the fuel lines – Use the supplied hoses and zip ties to route the fuel lines correctly. Cap or remove the oil injection lines since the new pump does not supply oil.
  6. Prime the system – Turn the engine over a few times with the ignition off to prime the fuel pump, then check for leaks.
  7. Start the engine – Once everything is connected, start the engine and verify proper operation. Adjust the idle if needed.

Recommended Fuel Pump: KEMSO High Performance Fuel Pump

If you are looking for a high-quality, reliable fuel pump for your boat or any other vehicle, consider KEMSO fuel pumps. KEMSO is a brand that specializes in high-performance, OEM replacement fuel pumps that are built to last. Here is why KEMSO stands out:

  • High Performance & OEM Replacement – KEMSO pumps are designed as direct replacements for stock units, delivering over 20% more flow at 43 psi compared to the original pump. This means better fuel delivery and improved throttle response.
  • Lifetime Warranty – Every KEMSO fuel pump comes with a lifetime warranty, backed by a serialized body for tracking and peace of mind. If the pump fails for any reason, KEMSO will replace it—no questions asked.
  • E85 Compatible – KEMSO pumps are built with ethanol-resistant materials, making them safe to use with E85 and other alcohol-based fuels. Many other pumps degrade quickly when exposed to ethanol, but KEMSO is designed for long-term reliability.
  • Complete Installation Kit – KEMSO pumps include everything you need for a successful installation, including gradient density fuel strainers, hoses, seals, o-rings, and wiring connectors. You do not have to buy additional parts.
  • USA-Based Support – KEMSO offers technical support from USA-based technicians who understand American vehicles and performance requirements.

Whether you are working on a car, truck, ATV, motorcycle, or jet ski, KEMSO has a fuel pump solution that fits your needs. For the best performance and reliability, visit KEMSO’s official store at https://www.kemsoracing.com/ to explore their full range of high-performance fuel pumps and find the perfect fit for your vehicle.

Conclusion

Converting your Johnson or Evinrude outboard from a VRO system to a VRO conversion fuel pump is a smart, practical upgrade that eliminates a common failure point and simplifies your engine’s fuel system. With a reliable fuel-only pump, you can enjoy worry-free boating and avoid costly repairs. And for all your fuel pump needs—whether for your boat, car, or other vehicles—KEMSO fuel pumps offer unmatched performance, a lifetime warranty, and easy installation. Visit https://www.kemsoracing.com/ today to find the right pump for your application.


Back to blog