Mercury MerCruiser - Water Pump Gasket (Pack of 2) - 27-34897
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The Mercury MerCruiser Quicksilver Engine Water Pump Gasket 27-34897 is an OEM-style sealing gasket used with the sea water pump housing on compatible GM-based MerCruiser V6 and V8 marine engines. It helps create a watertight seal at the pump mounting surface to prevent cooling-water leaks and support proper engine cooling.
Key Features
- Genuine Mercury/MerCruiser water pump gasket
- Part number: 27-34897
- Also referenced as 34897
- Used with sea water pump housing applications
- Fits select GM-based V6 and V8 marine engines
- Commonly sold as a pack of 2
- Helps prevent coolant loss and overheating
Engine Compatibility
Used on select GM-based MerCruiser V6 and V8 marine engines, including 4.3L, 5.0L / 305 CID, 5.7L / 350 CID, and 6.2L / 377 CID applications. Also associated with select 350 Mag, ski engine, 300 Tempest, 320 EFI, and 280 TRS engine configurations.
Serial Number Fitment Notice
Verify fitment by engine serial number, sea water pump style, and parts diagram before ordering. Pump gasket fitment can vary by engine block, pump housing, cooling-system layout, and production range.
When This Part Needs Replacement
Replace this gasket whenever the sea water pump is removed or serviced, or if the gasket is torn, compressed, leaking, oil-soaked, brittle, or damaged during pump replacement.
Installation Notes
Clean the pump and engine mounting surfaces before installation. Do not reuse a compressed or damaged gasket. Inspect the pump housing, fasteners, impeller condition, pulley alignment, and surrounding hoses during service.
Alternate/Superseded Part Numbers
Replaces Mercury 2734897 and BRP/OMC 3852477. Common aftermarket interchanges include Sierra Marine 18-0891, Mallory Marine 9-61600, and GLM Products 31380.
Parts Desk Insight
Water pump gaskets are simple parts, but they protect the cooling system from leaks at a high-flow service point. If the pump is already off, replacing the gasket is the right move instead of risking a repeat leak.
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
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.