OEM PART NUMBERS:
Mercury: 852087, 852087A1, 852087A2, 852087A3
Mercury: 91-881834A1 / 881834A1
Mercury: 91-852087, 91-852087A1, 91-852087A2, 91-852087A3

SPECIFICATIONS:
Type: Dual Fuel/Air Pressure Gauge
Function: Simultaneous fuel and air pressure testing
Connection: Schrader valve test ports on fuel and air rails
Platform: Mercury DFI Optimax, Verado, DFI Sport Jet
Weight: 2 lbs
Condition: New

APPLICATIONS:
Mercury DFI Optimax Outboards — All HP ratings
Mercury Verado Outboards — 135, 150, 175, 200, 225, 250, 275, 300 HP
Mercury DFI Sport Jet
All Mercury outboard models equipped with schrader valve fuel and air test ports

⚠️ Verify OEM part number from your original unit before ordering to ensure proper fitment.

OEM Grade Dual Fuel/Air Pressure Gauge — Mercury DFI Optimax and Verado
Professional-grade dual pressure gauge designed for simultaneously checking fuel and air pressure on Mercury DFI Optimax and Verado outboard engines. This diagnostic tool connects directly to the schrader valve test ports on both the fuel and air rails, allowing technicians to monitor both pressures at once for efficient troubleshooting. Essential for diagnosing fuel delivery issues, air compressor problems, and regulator malfunctions on Optimax DFI systems. The Optimax fuel system operates with fuel pressure approximately 10-15 PSI higher than air rail pressure, and this dual gauge allows quick verification of the correct pressure differential. Also compatible with Mercury DFI Sport Jet applications. Replaces Mercury 852087, 852087A1, 852087A2, 852087A3, and 91-881834A1. This item fits various applications by part number — always verify your OEM part number before ordering. New aftermarket unit built to OEM specifications for reliable pressure readings. Always verify your OEM part number before ordering to ensure compatibility.