Quicksilver O-Ring 8M0204651 – Mercury MerCruiser OEM
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Quicksilver O-Ring 8M0204651
This genuine OEM O-ring is used throughout Mercury and MerCruiser engine and drive assemblies to seal fluid passages, housings, and fittings against oil, water, and fuel intrusion. Getting the right O-ring matters — even a small difference in compound, durometer, or dimensions can lead to a seal that fails prematurely under heat and pressure. This is the exact part called out in the Mercury parts diagram, engineered to the same spec as what came out of the factory.
Key Specifications
- Part Number: 8M0204651
- Type: O-Ring
- Genuine OEM — not aftermarket
Common Applications
Use this O-ring wherever the Mercury or MerCruiser parts diagram specifies part number 8M0204651. It appears across multiple engine families and drive configurations — always verify against your model’s current parts diagram, serial number, and assembly location before ordering.
When to Replace
Replace any time you disassemble a sealed joint and the existing O-ring shows signs of flattening, cracking, hardening, swelling, or surface contamination. O-rings are a one-time-use seal — always install a fresh one on reassembly rather than reusing the old part.
Installation Notes
Clean mating surfaces thoroughly before installation. Lightly lubricate the O-ring with the appropriate fluid (fuel-safe grease or the system fluid) to ease installation and prevent tearing. Follow the Mercury service manual for orientation and torque specifications on the surrounding hardware.
Related Products
Parts Desk Insights
Best used as a direct OEM replacement during fuel system, cooling system, or drive service where the parts diagram calls for 8M0204651. This O-ring is a common inclusion in rebuild and reseal jobs on MerCruiser sterndrive and Mercury outboard assemblies — order a spare if you’re doing a full service. Always match by part number: O-rings that look identical can differ in compound and will fail prematurely in the wrong application. If your assembly has been repowered or updated, cross-reference the current diagram to confirm this number hasn’t been superseded.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.