Mercury MerCruiser Quicksilver — Exhaust Expansion Plug — 864689
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Mercury MerCruiser Quicksilver Exhaust Expansion Plug — 864689
This genuine Mercury expansion plug, also catalogued as 19-864689, closes a specified opening in a compatible exhaust manifold or elbow assembly. Match the plug to the exact parts diagram and assembly before ordering.
Part Details
- Part number: 864689
- Full service number: 19-864689
- Product type: expansion plug
- System: MerCruiser exhaust assembly
Compatible Applications
Use only where your MerCruiser exhaust manifold, elbow, or riser parts diagram specifies 864689 or 19-864689. Verify the engine and exhaust-assembly serial numbers against the diagram; the number and location of plugs can vary by assembly.
When to Replace
Replace a plug that is leaking, corroded, loose, or damaged during exhaust service. Inspect and clean the bore, then follow the applicable MerCruiser service procedure for installation.
Related Exhaust Parts
- Mercury MerCruiser exhaust manifold — 8M0185794
- Mercury MerCruiser exhaust elbow assembly — 864591T02
These are separate exhaust parts in the store, not a confirmed fitment list for this plug. Check the parts diagram for your assembly before ordering them together.
Technical FAQ
How many plugs do I need?
Quantity depends on the manifold or elbow assembly. Check the diagram for your serial-number range rather than assuming a universal quantity.
Is 19-864689 a different part?
It is the full service-number form of the listed 864689 expansion plug.
Parts Desk Insights
Best use case: replace a leaking or damaged plug during exhaust manifold or elbow repair when your parts diagram specifies this number.
Common mistake: ordering a fixed number of plugs without checking how many the specific assembly calls for.
Sizing and fitment guidance: compare the original plug and machined opening with the diagram for your exact exhaust assembly and serial number before ordering.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 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.