Proper fuel delivery is critical for the reliability and performance of Mercury EFI and Pro Max two-stroke outboards. At Buckshot Racing #77, we now offer two replacement fuel pump options depending on the fuel system used on your engine.
Customers can choose either the Internal VST Fuel Pump & Filter Kit or the External Pre-VST Fuel Pump, both designed to replace aging or failing Mercury OEM components.
These pumps service many Mercury 2.5-liter and 3.0-liter EFI outboards built between 1993 and 2002, including high-performance engines used on bass boats, offshore hulls, and performance applications.
Option 1 – Internal VST Fuel Pump & Filter Kit
The first option is the Internal VST Fuel Pump & Filter Kit, designed to replace the electric fuel pump located inside the Vapor Separator Tank (VST). This pump is responsible for supplying pressurized fuel to the injectors after the fuel has been separated from vapor within the tank.
This kit replaces several Mercury OEM part numbers including 808505T01, 809088T1, 808505-T01, and 809088-T1. It is used on a wide range of Mercury EFI engines such as 2.5-liter 150 HP, 175 HP, 200 HP, 225 Pro Max, and 240 SportJet engines, as well as 3.0-liter 225 HP, 250 HP, 250XB, 300 Pro Max, 300 Super Magnum, and 300X outboards.
Inside the VST system, fuel is stored and separated so that only liquid fuel reaches the injectors. The electric fuel pump delivers the required pressure and flow rate to maintain proper engine operation, while the fuel filter removes debris and contaminants before the fuel reaches the injectors.
The Buckshot Racing #77 VST Fuel Pump Kit includes the replacement pump, filter, and installation hardware such as the 1/8-inch fittings, jam nuts, washers, 3/16-inch fittings, jam nuts, and internal tooth lock washers required to complete the service.
Replacing the internal VST pump and filter during maintenance helps restore proper fuel pressure and ensures a clean fuel supply for the EFI system.
Option 2 – External Pre-VST Fuel Pump
The second option is the External Pre-VST Fuel Pump, designed for engines that use an external electric pump mounted before the VST. This pump supplies fuel from the tank to the Vapor Separator Tank where the internal high-pressure pump then feeds the injectors.
This external pump replaces Mercury OEM part numbers 14307A1, 14307T01, 14307T, 14307T1, and 143071. It is commonly used on Mercury EFI outboards where the external pump provides lift and consistent fuel delivery to the VST system.
When the pre-VST pump begins to weaken or fail, engines may experience hard starting, fuel starvation at high RPM, or inconsistent fuel pressure. Replacing the external pump restores proper fuel supply to the VST system.
Compatible Mercury EFI and Pro Max Engines
Both fuel pump options support many Mercury Marine EFI and high-performance outboards built during the 1990s and early 2000s.
Common engines include Mercury 2.5-liter 150 HP, 175 HP, 200 HP, and 225 Pro Max, as well as 240 SportJet applications. The pumps are also widely used on 3.0-liter Mercury engines including 225 HP, 250 HP, 250XB, 300 Pro Max, 300 Super Magnum, and the 300X.
These engines powered many bass boats, offshore performance hulls, and high-output recreational boats where consistent fuel delivery is essential for proper EFI performance.
Cross-Reference and Replacement Part Numbers
The internal VST fuel pump and related components correspond with several Mercury and aftermarket replacement numbers.
Common cross-reference numbers include 18-7341, 600-110-01, 65L-13907-00-00, 66K-13907-00-00, 67H-13907-00-00, 808505, 808505T, 808505T01, 809088, 809088T, 809088T1, 827682, 827682T, and 8090P.
These numbers are often referenced in service manuals and replacement parts catalogs when servicing Mercury EFI VST fuel systems.
Choosing the Correct Pump
Because Mercury used both internal VST pumps (mid-later 1990s) and external pre-VST pumps (early 1990s) depends on the engine configuration, customers can select the correct option at checkout.
Selecting “VST Pump” provides the internal pump and filter kit designed for Vapor Separator Tank service. Selecting “Pre-VST Pump” provides the external fuel pump used before the VST in the fuel delivery system.
Both options restore reliable fuel flow and help maintain proper fuel pressure for Mercury EFI engines.
Maintaining Reliable Fuel Delivery
Over time, fuel pumps and filters wear due to heat, ethanol exposure, and contamination. Replacing aging pumps helps prevent fuel starvation, injector damage, and performance issues.
For owners maintaining Mercury 2.5L and 3.0L EFI outboards—including Pro Max, SportJet, 300 Pro Max, and 300X engines—these replacement fuel pump options provide a reliable solution for restoring proper fuel system operation.
Contact Mike Hill at +1-714-697-1716 or email mike@buckshotracing77.com for technical support.