Mercury MerCruiser Quicksilver Thermostat Assembly 8M0174561
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Mercury MerCruiser / Quicksilver Thermostat Assembly – 8M0174561
Maintain proper engine cooling and operating temperature with the genuine Mercury Marine / Quicksilver 8M0174561 Thermostat Assembly. This OEM thermostat assembly regulates coolant flow through the engine, helping the engine reach and maintain the correct operating temperature for optimal performance and efficiency.
The assembly includes a 140°F (60°C) thermostat housed in a corrosion-resistant composite thermostat housing, designed for durability and long service life in marine environments.
Key Features
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Genuine Mercury / Quicksilver OEM thermostat assembly
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140°F thermostat maintains correct engine operating temperature
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Durable high-temperature composite housing with corrosion resistance
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Integrated stainless-steel thermostat element for reliable operation
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Designed for direct replacement installation in compatible Mercury engines
Part Details
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OEM Part Number: 8M0174561
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UPC: 745061633704
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Thermostat Rating: 140°F
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Product Type: Thermostat and housing assembly
Supersedes
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892864T04 (earlier Mercury part number)
Compatible Mercury Engines
Commonly used on Mercury Verado FourStroke outboard engines, including:
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135 HP EFI Verado (4-cylinder)
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150 HP EFI Verado (4-cylinder)
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175 HP EFI Verado (4-cylinder)
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200–300 HP Verado (6-cylinder)
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350–400 HP Verado (2.6L L6)
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400R Racing engines
Compatibility depends on engine model and serial number range.
Function
The thermostat controls coolant flow within the engine. When the engine is cold, it remains closed to allow the engine to warm up quickly. Once operating temperature is reached, the thermostat opens to circulate cooling water and prevent overheating.
Important Compatibility Note
Thermostat assemblies vary depending on engine family, cooling system configuration, and serial number range. Always verify compatibility using the engine serial number before ordering to ensure the correct replacement part.
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.