Fuel pressure regulators are essential components in fuel injection systems, ensuring consistent fuel pressure for optimal engine performance.
 
In Mercury 2.5 EFI 2-stroke V6 outboards, maintaining the correct fuel pressure is crucial for efficient fuel atomization, combustion, and overall engine operation.
 
39 PSI Fuel Pressure Regulator (Gold) – Mercury (94820 Gold)
 
The Mercury 94820 is a 39 PSI fuel pressure regulator designed for Mercury 2.5L EFI Offshore engines. This regulator, also known by part numbers 94820T and 29482, ensures proper fuel delivery by maintaining a steady 39 PSI in the fuel rail. It plays a critical role in regulating fuel flow, returning excess fuel to the tank, and adjusting pressure based on engine load and speed.
 
56 PSI Fuel Pressure Regulator (Silver) – Mercury Racing S3000 and Drag 300 (12026 Black)
 
For high-performance applications such as the Mercury Racing S3000 and Drag 300, a 56 PSI Bosch EFI fuel pressure regulator is required. The original OEM part number 8M0051195 (superseding 12026-2) is no longer available (NLA) from Mercury Marine, Quicksilver, or Bosch. This regulator maintains a higher fuel pressure, ensuring optimal fuel delivery for these high-output engines.
 
Key Functions of Fuel Pressure Regulators:
 
Maintain Constant Pressure: Ensures consistent fuel pressure in the fuel rail, allowing for proper fuel atomization and combustion.
Fuel Return System: Excess fuel not used by the injectors is returned to the fuel tank via a return line.
Vacuum Assistance: Engine vacuum slightly adjusts fuel pressure based on load and speed, optimizing fuel delivery.
 
When selecting a replacement fuel pressure regulator, choose based on your engine’s fuel pressure requirements:
 
39 PSI Fuel Pressure Regulator (Gold): A replacement for the Mercury 94820 (OEM part numbers 94820T, 29482).
 
56 PSI Fuel Pressure Regulator (Silver): Suitable for Mercury Racing S3000 and Drag 300, replacing the Black 56 PSI Bosch EFI Fuel Pressure Regulator (OEM part numbers 8M0051195, 12026-2).
 
By ensuring the correct fuel pressure regulator is installed, you can maintain optimal engine performance, fuel efficiency, and reliability in your Mercury 2.5 EFI 2-stroke V6 outboard.
 
Mercury Racing 2.5 Liter EFI ECU Fuel Pressure PSI Chart
 
Box
Race EFI Motor
PSI
RPM Limiter
A29
2.0 1994
39
11,500
A40
2.4
39
7,700
A32
2.5 ROS 1994
39
8,200
A36
2.5 ROS 1995
39
8,200
A48
2.5 Drag 1995
39
11,500
A33
2.5 S3000 1994
39
9,250
A49
2.5 1996
39
7,750
A62
2.5 1996
39
7,750
A4
2.4
39
7,500
A1
2.5 280 Consumer
39
7,600
A5
2.5 280 ROS
39
8,200
A45
2.0 1995
56
11,500
A46
2.0 1995
56
11,500
A53
2.0 1995 Service Only
56
9,259
A63
2.5 Drag 1995+
56
11,500
A47
2.5 S3000 1995
56
9,250
A52
2.5 S3000 1995
56
9,250
A61
2.5 S3000 1996
56
9,250
A65
2.5 1997 PROP Tour
56
8,600
A2
2.0 Mod U
56
11,500
A3
2.0 PROP Tour
56
9,400
A6
2.5 Drag
56
11,500
A7
2.5 S3000
56
9,350
A8
2.5 S3000
56
9,350
A10
2.5 S3000 PROP Tour
56
8,650
A13
2.5 DRAG 2001
56
11,500
A14
2.5 S3000
56
10,100
 
Contact Mike Hill at +1-714-697-1716 or email mike@buckshotracing77.com for technical support.