Mercury MerCruiser Quicksilver Multi-Application O-Ring 8M0214925

Mercury MerCruiser Quicksilver O-Ring 8M0214925

Mercury MerCruiser Quicksilver 8M0214925 is a genuine OEM sealing O-ring used in multiple Mercury Marine engine, sterndrive, gearcase, and cooling-system assemblies. Depending on the application, Mercury parts diagrams identify it in bearing-carrier assemblies, transfer-port covers, seawater pumps, and water-pump assemblies.

Compatible Applications

• Select gearcase bearing-carrier assemblies
• Select transfer-port cover assemblies
• Select seawater pump body and impeller assemblies
• Select water-pump assemblies
• Mercury Marine engine and drive assemblies whose OEM diagram specifies 8M0214925, 33465, or an officially superseded application number

Fitment notice: This is a multi-application seal used in several different assemblies. Confirm compatibility using the engine or drive serial number and the exact OEM parts diagram. Do not identify it by appearance or approximate diameter alone.

Part Details

• Current OEM part number: 8M0214925
• Mercury prefix reference: 25-8M0214925
• Brand: Mercury MerCruiser Quicksilver
• Product type: Multi-application sealing O-ring
• Condition: New

Alternate and Superseded Part Numbers

• 33465: Superseded directly to 8M0214925
• 853220: Earlier application number shown in select cooling-system diagrams now serviced by 8M0214925

Key Features

• Genuine OEM sealing component
• Used in multiple engine, drive, gearcase, and cooling-system assemblies
• Identified as a bearing-carrier O-ring in select gearcases
• Also used in select transfer-port cover, seawater-pump, and water-pump assemblies
• Current replacement for earlier Mercury 33465 applications

When to Replace This O-Ring

Replace the O-ring whenever the component it seals has been opened for service or if the original seal is flattened, permanently compressed, cut, nicked, stretched, hardened, or distorted. Replacement is also appropriate when leakage is present or when a pump, bearing carrier, or transfer-port assembly is being rebuilt.

Installation Notes

Clean the O-ring groove and mating surfaces, removing corrosion, old lubricant, and debris that could interfere with sealing. Install the O-ring without twisting, pinching, or excessive stretching. Use only the lubricant, sealant, and assembly procedure specified for the exact application. For bearing-carrier installations, follow the applicable gearcase service procedure and inspect surrounding seals while the carrier is removed.

Technical FAQ

Is this O-ring limited to one engine family?
No. It appears in several unrelated Mercury Marine assemblies, so the serial-specific parts diagram is the correct fitment reference.

Can it be identified by size or appearance?
No. Similar-looking Mercury seals can have different dimensions and applications. Match the complete part number.

Should it be reused after disassembly?
Installing a fresh O-ring is the sensible approach when the sealed component is already apart, especially if the original seal is compressed or damaged.

Parts Desk Insights

Best use case: Replacing the specified seal whenever a compatible bearing carrier, transfer-port cover, seawater pump, or water-pump assembly is opened for service.

Most common mistake: Ordering by apparent size or installation location. This part appears in several assemblies, while similar-looking O-rings may not share the same dimensions.

Fitment guidance: If the exact OEM diagram calls for 33465 or 8M0214925, use the current part. Treat 853220 as application-specific and confirm it against the diagram before ordering.