Maintaining a proper seal in the exhaust system is essential for the performance and reliability of any Mercury V6 outboard. The Exhaust Split Plate Adapter Gasket, commonly referenced under Mercury part numbers 183071 and 183076, is designed to seal the connection between the exhaust adapter plate and the exhaust divider or split plate assembly on Mercury 2-stroke outboards.
 
This gasket plays a critical role in keeping exhaust gases contained within the exhaust path while preventing water intrusion into the powerhead. Proper sealing at this point ensures consistent exhaust flow, stable engine temperatures, and reliable performance for both recreational and high-performance applications.
 
Buckshot Racing #77 supplies replacement Mercury exhaust split plate adapter gaskets that match the fitment and sealing requirements of original Mercury components used across a wide range of Mercury Marine, Mercury Racing, and Mariner V6 outboards.
 
Designed for Mercury 2.5 Liter V6 Outboards
The Mercury Exhaust Split Plate Adapter Gasket (183071 / 183076) fits many Mercury 2.5 Liter V6 two-stroke outboards used in both fishing and performance applications. These engines were widely produced from the early 1990s through the mid-2000s and remain popular today in bass boats, performance hulls, and repowered vessels.
 
Mercury 135 HP, 150 HP, 175 HP, and 200 HP 2.5L V6 outboards, including carbureted and EFI models, along with XR6 performance variants. The gasket is also used in certain Mercury 200 XS OptiMax and DFI-based platforms that share similar exhaust adapter plate sealing requirements.
These engines are frequently found on bass boats, fishing boats, and high-performance lake boats, where reliable exhaust sealing is essential for long engine life and proper cooling system operation.
 
Function of the Exhaust Split Plate Adapter Gasket
The exhaust split plate adapter gasket seals the mating surfaces between the exhaust adapter plate and the divider plate assembly located in the midsection of the outboard.
 
In a Mercury V6 two-stroke outboard, exhaust gases leave the cylinders and travel through the exhaust chest before exiting through the midsection and lower unit. The gasket ensures that exhaust pressure remains properly contained while preventing cooling water from leaking into unwanted areas.
 
A worn or damaged gasket can lead to several issues, including exhaust leakage, reduced performance, or cooling system imbalance. During engine service or rebuild work, replacing the Mercury gasket 183071 or 183076 helps restore proper sealing and maintain optimal engine operation.
 
Cross-Reference and Replacement Part Numbers
This gasket is commonly referenced by several Mercury and aftermarket part numbers. Including these numbers helps identify compatible replacements during maintenance or rebuild work.
Common cross-reference part numbers include: 183071, 183076, 37570, and 510-36
 
These part numbers are used across various Mercury Marine service catalogs and aftermarket gasket suppliers for the same exhaust adapter sealing location.
When servicing Mercury V6 engines, verifying the correct gasket by part number ensures proper fitment and sealing performance.
 
Importance During Engine Service or Rebuilds
When performing major service work on Mercury V6 outboards—such as powerhead removal, exhaust plate inspection, or midsection maintenance—the exhaust split plate adapter gasket should always be replaced.
 
Over time, heat cycles, exhaust pressure, and exposure to water and combustion byproducts can cause the gasket material to compress, harden, or deteriorate. Replacing the gasket ensures that the exhaust adapter plate seals correctly once the engine is reassembled.
 
For builders working on Mercury 2.5L carbureted engines, EFI models, XR6 engines, or 200 XS Opti and DFI outboards, installing a fresh gasket is a simple but important step that protects the engine from exhaust leaks and cooling system issues.
 
Supporting Mercury V6 Outboard Maintenance
The Mercury Exhaust Split Plate Adapter Gasket (183071 / 183076) remains an important service component for maintaining legacy Mercury V6 outboards still widely used today.
 
From 135 HP and 150 HP fishing engines to 175 HP and 200 HP performance setups, along with XR6 models and certain 200 XS OptiMax applications, this gasket helps maintain the integrity of the exhaust and cooling systems.
 
At Buckshot Racing #77, we support the ongoing maintenance and restoration of Mercury two-stroke outboards by supplying proven replacement parts for the engines that continue to power bass boats, race boats, and performance hulls around the world.
 
Contact Mike at 714-697-1716 or mike@buckshotracing77.com for technical support.