Mercury Water Pump Repair Kit 821354A2
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Mercury MerCruiser 821354A2 is a genuine OEM water pump repair kit for select Mercury and Mariner outboards. This kit is designed to restore proper water pump performance and cooling-system function, and Mercury describes it as one of the more complete repair kits for these applications. The published fitment trail centers on 25HP to 50HP 2-stroke and 4-stroke outboards, with especially strong support across the 25/30/40/45/50HP range.
Key Features
- Genuine Mercury MerCruiser / Quicksilver part number 821354A2
- Water pump repair kit for select 25HP–50HP outboards
- Includes water pump impeller, drive key, face plate, gaskets, and water tube seal
- Designed to help restore cooling flow and water pump function
- OEM service kit for Mercury and Mariner outboard applications
Engine Compatibility
The strongest confirmed application trail covers Mercury and Mariner 25HP, 30HP, 40HP, 45HP, and 50HP outboards in both 2-stroke and 4-stroke configurations. Mercury's own listing describes it broadly for 25–50HP 2-stroke and 4-stroke outboards, while additional parts references show extensive serial-range coverage across those engine families. Exact fitment should still be confirmed by engine serial number before ordering.
Serial Number Fitment Notice
Please confirm fitment by engine model and serial number before ordering. Mercury specifically directs owners to use the owner's manual or service manual for exact application and replacement instructions.
When This Part Needs Replacement
Replace this kit when the water pump is due for service, when the impeller has worn or failed, or when cooling performance has dropped and the pump needs a full refresh. Since this is a repair kit rather than a single loose impeller, it is a strong choice when servicing multiple wear components in the water pump assembly at the same time.
Installation Notes
Install only on the correct Mercury or Mariner application and verify fitment before ordering. Matching by part number, engine horsepower, stroke type, and serial number is the safest approach. Mercury also recommends using the service manual for exact replacement instructions.
Alternate / Superseded Part Numbers
- 821354A2
- Related replacement references commonly grouped with this kit include 821354A1 and 821354A04, but those should still be confirmed against the exact application before substituting.
Parts Desk Insight
The biggest advantage of 821354A2 is that it goes beyond just the impeller. For a proper cooling-system service on compatible small and mid-range Mercury/Mariner outboards, this kit covers the key pump wear items in one OEM package.
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.
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For return authorization, please contact our support team before shipping anything back.