Mercury MerCruiser Exhaust Elbow Gasket 862356 | 27-862356 | 496 Magnum 8.1S OEM
In stock items ship same or next day.
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Mercury MerCruiser OEM Exhaust Elbow Gasket — Part 862356
- Part Number: 862356 (Mercury catalog format: 27-862356)
- Brand: Mercury Marine / MerCruiser / Quicksilver (Genuine OEM)
- Official Product Type: Gaskets & Seals — Exhaust System
- System: Exhaust Manifold / Elbow Assembly
- Diagram Position: Elbow-to-manifold joint — seals between the exhaust manifold and the exhaust elbow/riser
- GTIN: 745061481909
- Qty Required: Verify per exhaust configuration — Mercury diagrams specify multiple gaskets depending on arrangement
What It Does
This OEM gasket seals the joint between the exhaust manifold and the exhaust elbow (riser) on select MerCruiser big-block engines. Mercury parts diagrams identify 862356 specifically at the elbow-to-manifold interface, where it keeps exhaust gases and cooling water properly contained within their intended passages. It is a distinct part from the related hardware listed nearby in Mercury exhaust diagrams — see the important note on part numbers below.
Compatible Applications
Verify fitment by engine serial number before ordering. Exhaust configurations can vary within the same engine family.
- MerCruiser 496 Magnum — sterndrive and inboard
- MerCruiser 496 Magnum H.O.
- MerCruiser 8.1S / 8.1L — inboard applications
- 8.1L TowSport
- 8.1L Plus Series
- 8.2L MAG / 8.2L MAG H.O.
- 496 H.O. Plus Series
- 540 Stroker 4V
Not sure it fits? Send us your MerCruiser engine serial number before ordering.
Part Numbers & Cross-References
- 862356 — Mercury OEM part number
- 27-862356 — Full Mercury catalog format
- GTIN: 745061481909
Important: 8M0207778 Is Not a Supersession for This Gasket
Mercury exhaust diagrams identify 8M0207778 as a washer, not as a replacement for gasket 862356. These are separate components within the same exhaust assembly. Do not substitute 8M0207778 for 862356 — confirm the correct part against your engine's serial-number-specific exhaust schematic before ordering either component.
When to Replace
Replace this gasket whenever the exhaust elbow or riser is removed from the manifold, or when inspection shows:
- Exhaust gas or water leakage at the manifold-to-elbow joint
- Burned, compressed, or deteriorated gasket material
- Corrosion around the sealing surfaces
- Gasket tearing or damage during disassembly
A used exhaust elbow gasket should not normally be relied upon to reseal after the joint has been disturbed.
Installation Notes
- Clean both mating surfaces and remove all remnants of the old gasket without damaging the manifold or elbow
- Inspect the manifold and elbow sealing surfaces for corrosion or erosion — damaged surfaces can cause leaks even with a new gasket
- Confirm 862356 is shown in your engine's serial-number-specific exhaust schematic before installation
- Check condition of exhaust studs, washers, and nuts before reassembly
- Position the gasket per the Mercury service procedure and torque fasteners evenly to specification
- Inspect for cooling-water or exhaust leakage after the engine reaches operating temperature
Related Parts
- Mercury MerCruiser OEM Engine Gasket 27-8M0150304 — additional MerCruiser exhaust/engine gasket for reference
Parts Desk Insights
On 496 and 8.1L exhaust service, the elbow gasket is the part most likely to fail to reseal after the joint has been opened — and it's inexpensive relative to the labor involved in getting back into the exhaust assembly. If the elbow is already off for any reason, replace this gasket as a matter of course. The most common issue we see is customers ordering 8M0207778 expecting it to replace 862356: these are two separate parts in the same exhaust diagram. Always confirm which item your schematic calls for before placing your order.
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.