The Mercury Replacement Lower Units from Buckshot Racing #77 are brand-new aftermarket gearcases manufactured by Sterndrive Engineering, Inc. for compatible 1976-2005 Mercury Marine and Mariner V6 two-stroke outboards using 2.0L, 2.4L, 2.5L and 3.0L powerheads.
 
These complete replacement gearcases are an alternative to rebuilding an original lower unit with worn gears, damaged bearings, corrosion, cracked housings, or other major internal damage. Each unit is supplied new and unmodified, ready for installation once the correct engine family, shaft length and gear ratio have been confirmed.
 
Buckshot Racing #77 offers configurations in 1.62:1, 1.75:1, 1.87:1 and 2.00:1 gear ratios for compatible 20-inch, 25-inch and 30-inch midsections, along with selected 3.0L stub-shaft applications.
 
Mercury 2.0L, 2.4L & 2.5L Lower Units
 
Option 1 – 20" Shaft, 2.00:1 Gear Ratio
Option 2 – 20" Shaft, 1.87:1 Gear Ratio
Option 3 – 25" Shaft, 2.00:1 Gear Ratio
Option 4 – 25" Shaft, 1.87:1 Gear Ratio
 
These configurations cover many older Mercury and Mariner 135, 150, 175, 200, and (earlier) 225 HP V6 two-stroke applications, depending on the original midsection and gearcase configuration.
 
Mercury 3.0L Lower Units
 
Option 5 – 20" Shaft, 1.75:1 Gear Ratio
Option 6 – 20" Shaft, 1.62:1 Gear Ratio
Option 7 – 25" Shaft, 1.75:1 Gear Ratio
Option 8 – 25" Shaft, 1.62:1 Gear Ratio
Option 9 – 30" Shaft, 1.75:1 Gear Ratio
Option 10 – Stub Shaft, 1.62:1 Gear Ratio
Option 11 – Stub Shaft, 1.75:1 Gear Ratio
 
These options provide replacement coverage for many compatible Mercury 3.0L V6 applications where the shaft length, driveshaft arrangement and gear ratio match the original lower unit.
 
Choosing the Correct Mercury Gearcase
 
A replacement lower unit should never be selected by horsepower alone. Before ordering, confirm the engine’s displacement, midsection length, driveshaft configuration and original gear ratio. A 20-inch midsection requires the correct 20-inch lower unit, while 25-inch, 30-inch and stub-shaft installations require their corresponding driveshaft configuration.
 
Gear ratio is equally important. Changing from a 2.00:1 to 1.87:1, or from 1.75:1 to 1.62:1, changes propeller speed relative to engine RPM and can affect acceleration, propeller selection and wide-open-throttle RPM.
 
For a normal replacement installation, matching the original gear ratio is generally the best starting point unless the boat’s entire setup is being intentionally changed.
 
Brand-New Sterndrive Engineering, Inc. Gearcases
 
These are new replacement lower units, not used, rebuilt, or remanufactured Mercury gearcases. Sterndrive Engineering, Inc. manufactures the complete replacement assembly as an aftermarket alternative for many older Mercury V6 applications where rebuilding the original gearcase may no longer be economical.
 
For customers maintaining classic 2.0L, 2.4L, 2.5L and 3.0L Mercury two-strokes, a complete new lower unit can eliminate the need to individually replace gears, bearings, shafts, seals and damaged housings.
 
3-Year No-Fault Manufacturer Warranty
 
New, unmodified Sterndrive Engineering, Inc. lower units are supplied with a 3-year no-fault manufacturer warranty, subject to the manufacturer’s current warranty terms and exclusions.
The gearcase must remain in its original manufactured configuration.
 
Modifying the water pickups, adding or modifying a nose cone, machining the housing, or otherwise altering the lower unit will void the manufacturer warranty.
 
The no-fault warranty also does not apply to commercial, competition, professional, or racing use.
 
This is particularly important for high-performance Mercury owners. Modifications commonly made to race gearcases for elevated engine heights or specialized water pickup arrangements can eliminate warranty coverage.
 
Installation and Lower Unit Hardware
 
Before installation, compare the new gearcase with the original unit and verify the driveshaft length, shift-shaft position, mounting configuration, and gear ratio.
 
Inspect the water tube, mounting studs, nuts, washers and sacrificial anodes while the lower unit is removed. Corroded or damaged hardware should be replaced rather than reused.
 
Buckshot Racing #77 also offers a Mercury Lower Unit Anode and Fastener Hardware Kit for compatible installations, making it easier to install the new gearcase with fresh mounting hardware and corrosion protection.
 
Always follow the manufacturer’s installation, lubricant, and break-in instructions for the specific replacement lower unit.
 
Shipping Information
 
Lower units ordered directly through BuckshotRacing77.com are available for Mainland USA shipping only through the website.
 
For international shipping, contact Mike directly so freight, destination requirements and shipping arrangements can be handled separately.
 
The Buckshot Racing #77 Sterndrive Engineering, Inc. Mercury Replacement Lower Unit program provides a practical solution for owners of classic Mercury V6 two-strokes who need a new gearcase rather than another rebuilt or used unit.
 
With 1.62:1, 1.75:1, 1.87:1, and 2.00:1 gear ratios, multiple shaft lengths, and coverage for compatible 2.0L, 2.4L, 2.5L, and 3.0L Mercury outboards, the correct replacement can be matched to a wide range of Mercury Marine and Mariner V6 applications.
 
Contact mike@buckshotracing77.com for any questions, to secure a delivery date, and to discuss installation or shipping costs.