9011A25 9011J7 Mercury 20" Long Shaft Gearbox | Genuine Used Part

🔧 Product Description

Genuine Mercury 100HP-125HP Four-Cylinder 20-Inch Gearcase - Part Numbers: 9011A25 / 9011J7

A genuine used black Mercury / Mariner lower unit for 100HP, 115HP and 125HP inline-four two-stroke outboards. The 20-inch gearcase uses a 2.07:1 ratio, a 14-tooth pinion and a three-jaw reverse clutch. Mercury 9011J7 is the later service assembly for the earlier 9011A25 family.

⚙️ Key Features

• Genuine Mercury / Mariner complete gearcase
• Later part number 1667-9011J7
• Earlier part number 9011A25
• 20-inch shaft and 2.07:1 gear ratio
• Three-jaw reverse-clutch configuration

🚤 Compatibility

Commonly used on

• Mercury and Mariner 100HP four-cylinder two-strokes
• Mercury and Mariner 115HP four-cylinder two-strokes
• Mercury and Mariner 125HP four-cylinder two-strokes

Typically suits

• Approximately 1987-and-later inline-four carburetted engines
• 20-inch long-shaft standard-rotation models
• Three-jaw reverse-clutch gear-housing charts
• Belgian and US serial ranges vary; verify the original complete assembly number
• HP Range: 100HP - 125HP
• Shaft Length: 20 inches / L
• Gear Ratio: 2.07:1
• Pinion Teeth: 14
• Reverse Clutch: Three-jaw

🔌 Function

The gearcase reduces engine speed, transmits torque to the propeller and provides forward, neutral and reverse selection.

⚠️ Common Signs of Failure

• Wrong three-jaw or six-jaw clutch specification
• Jumping out of reverse
• Water in the gear lubricant
• Bearing or gear noise
• Bent shaft or damaged housing

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 9011J7 replaces or consolidates 9011A25, 9011A81 and 9011G39 applications
• 9011R7 is a related equivalent service reference in some catalogues
• Do not substitute six-jaw 9011J15 without confirming the complete gear-housing chart

OEM / Related Numbers

• 1667-9011J7
• 9011J7
• 9011A25
• 9011A81
• 9011A62
• 9011G39
• 9011R7
• 14-tooth pinion / 2.07:1 gear family

Aftermarket / Verified Equivalents

• BoatEngine remanufactured 9011J7 lower unit
• Professionally remanufactured Mercury I-4 three-dog gearcases
• Aftermarket gear, bearing, seal and water-pump kits
• Used genuine 9011J7 / 9011A81 / 9011G39 units
• New old stock Mercury complete assemblies where available

📦 Condition

• Genuine used part
• Removed from running engine or vessel where applicable
• In good working condition unless otherwise stated