A reliable exhaust seal is essential on any high-RPM two-stroke, and it’s especially important on the classic Mercury 2.5 Liter V6 platform. The Mercury Exhaust Pipe Adapter Gasket is designed to seal the exhaust pipe adapter interface and maintain consistent sealing through vibration, high heat, and repeated thermal cycling.
 
This gasket is commonly identified by Mercury part number 782461, and it is also frequently cross-referenced as 18-0135, 32880, and 78246 in aftermarket and interchange listings.
 
Fits Mercury and Mariner 2.5L V6 outboards (1991–2005)
This exhaust pipe adapter gasket fits Mercury Marine and Mariner 2.5 Liter V6 outboards manufactured from 1991 to 2005, including common horsepower families such as 135 HP, 150 HP, 175 HP, and 200 HP 2.5L V6 models. It’s also commonly associated with performance and model naming used in parts searches and service notes, including Mercury 225 Pro Max, Mercury 225X EFI, and Mercury 200XS Optimax listings that reference the same gasket family in parts cross-checks.
 
If your parts diagram or service list calls out 782461 (or the cross numbers 18-0135, 32880, or 78246), you’re in the correct gasket category for these Mercury/Mariner 2.5L applications.
 
Why gasket material matters on a Mercury 2.5L
Two-stroke V6 exhaust components see high temperatures, pressure pulses, vibration, and wide heat cycles. A weak gasket can compress unevenly or degrade over time, leading to leaks and repeat service work.
 
This gasket is made from Victor Reinz 1.1 mm composite material, composed of high-strength aramid fibers, inorganic fillers, and an elastomeric binder formulated to resist fuel, oil, and long-term heat exposure. That construction provides excellent dimensional stability and sealing integrity under high-RPM conditions and repeated thermal cycling.
 
When to replace the exhaust pipe adapter gasket
Replace the gasket anytime the exhaust adapter is removed, during powerhead service, or when you’re addressing an exhaust leak. Because these gaskets compress to seal, reusing an old gasket often leads to inconsistent sealing on reassembly—especially on engines that see frequent teardown or hard use.
 
Part number reference (for ordering and cross-checking)
This gasket is commonly listed as 782461, with cross-references 18-0135, 32880, and 78246. Matching the number in your Mercury/Mariner diagram is the best way to confirm fitment.
 
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