8M0204645 Mercury MerCruiser O Ring | Genuine Quicksilver OEM Part

🔧 Product Description

Genuine Quicksilver O-Ring - Part Number: 25-8M0204645

Genuine Quicksilver O-ring used in Mercury / MerCruiser service assemblies where the current 25-8M0204645 sealing reference is specified. This O-ring supersedes earlier 25-21836 and is used in selected Mercury outboard and MerCruiser assemblies requiring this exact O-ring size and profile.

⚙️ Key Features

• Genuine Quicksilver OEM O-ring

• Correct Mercury part number 25-8M0204645

• Supersedes earlier 25-21836

• Direct replacement sealing O-ring

• Used in Mercury / MerCruiser assemblies requiring the 25-21836 / 25-8M0204645 seal family

• Important service item during reseal, housing or component removal work

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 25-8M0204645 → Supersedes 25-21836

• 25-21836 earlier OEM O-ring reference

• 21836 short-form Mercury reference

OEM / Related Numbers:

• 25-8M0204645

• 8M0204645

• 258M0204645

• 25-21836

• 21836

• 20679 related older seal / O-ring family reference

• F53795 related reference where cross-listed

• O-ring

• Mercury service O-ring

• MerCruiser service O-ring

Aftermarket / Verified Equivalents:

• Mallory: 9-76565

• MarinePartsDistributors: 526-30B2

• Volvo Penta cross-reference: 3852565 where matched by size and material

• Aftermarket O-ring equivalents may be available by direct 25-8M0204645 / 25-21836 match

• Use exact material, section size and application match before substituting

🚤 Compatibility

Commonly used on:

• Mercury outboard service assemblies where 25-8M0204645 is specified

• Mercury 6-cylinder FourStroke / Verado-style service applications where this O-ring is shown

• MerCruiser assemblies using the earlier 25-21836 O-ring reference

• Housing, plug or seal locations requiring this exact OEM O-ring profile

Typically suits:

• Engine / drive models:

• Mercury 6-cylinder FourStroke applications where O-ring 25-8M0204645 / 25-21836 is specified

• Mercury Verado service assemblies where 25-8M0204645 is shown in the serial-numbered diagram

• Mercury EFI / FourStroke outboard assemblies requiring O-ring 25-21836 replacement

• MerCruiser service assemblies where 25-21836 has superseded to 25-8M0204645

• Mercury / MerCruiser components using this O-ring as a direct seal in the OEM diagram

• Engine / Drive Type: Mercury outboard and MerCruiser applications by diagram

• System Type: OEM O-ring / sealing component

• Fitment Note: Match by part number and diagram location because O-rings vary by material, diameter and section thickness.

🔌 Function

The O-ring seals the specified component joint to prevent oil, water, fuel, air or lubricant leakage depending on its diagram location.

Common signs of failure:

• Leakage around the sealed component

• O-ring flattened, cut or swollen

• O-ring brittle or hardened from age

• Component removed and O-ring disturbed

• Pressure or vacuum test failure where used in a sealed housing

• Incorrect generic O-ring previously fitted

📦 Condition

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging