Mercury Outboard Lower Unit Replacement – Fits Most 3 & 4 Cylinder – 2.07 & 2.33 Ratios – 2 & 4 Stroke – Aftermarket

Mercury Outboard Lower Unit Replacement – Fits Most 3 & 4 Cylinder Models – 2.07 & 2.33 Ratios – 2 & 4 Stroke – Aftermarket

Upgrade your Mercury outboard with this premium aftermarket lower unit, engineered to replace most Mercury 3 & 4 cylinder models. Designed for both 2-stroke and 4-stroke engines (70–125 HP, 1987 & newer), this unit offers a reliable solution for repairing or restoring your marine performance. Ideal for owners looking for a cost-effective, high-quality replacement that matches OEM standards.

Key Features

• Compatible with most Mercury 3 & 4 cylinder 2-stroke outboards (1987 & newer, 70–125 HP)

• Also replaces 75–115 HP 4-stroke models below Serial #OT801000

• Available in 2.07 & 2.33 gear ratios for optimal performance

• Supports both 2-stroke and 4-stroke applications

• Aftermarket part with robust construction for durability

• Not a fit for 3-jaw lower units without a midsection shift shaft update

Specifications Table

Application Guide

• Replaces most 3 & 4 cylinder 2-stroke (1987 & newer, 70–125 HP)

• Fits 75–115 HP 4-strokes below Serial #OT801000

• Will NOT replace a 3-jaw unit without changing the midsection shift shaft

• Only for 4-1/4″ bullet diameter cases

• Not compatible with models using a plastic water pump housing

• You must verify the correct gear ratio (2.07:1 or 2.33:1)

• Confirm engine type (2-stroke carb, DFI, or 4-stroke), and shaft length (L/XL/LL)

• LL model (22.5″ shaft) not supported

Why Choose This Mercury Lower Unit?

This unit is  built to precise specs for long-lasting, reliable operation. Each assembly is thoroughly tested and ready for installation, giving you confidence in both fit and performance. For questions on compatibility, call us with your serial number for expert fitment guidance.

Looking for other Mercury lower unit options?

• Browse all Mercury Lower Units here

More Information : Mercury Marine