MerCruiser Fogging Oil 858081K03
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Mercury 858081K03 is a genuine OEM Storage Seal fogging oil for winterization and long-term storage of gasoline engines. Mercury describes it as a 12 oz spray can with a heavy, sticky formula that forms a protective barrier on internal metal surfaces to help prevent rust during storage.
Key Features
- Genuine Mercury Marine / Quicksilver OEM product
- Part number 858081K03
- 12 oz spray can
- Heavy, sticky spray lubricant for internal engine protection
- Helps keep cylinders lubricated to reduce risk of cylinder or piston damage at restart after storage.
Engine Compatibility
Mercury states this fogging oil is suitable for 2-stroke and 4-stroke gasoline engines, including carbureted, fuel-injected, and catalyzed engines. It is marketed for marine use on outboards and sterndrives, while also being usable on other gasoline engine equipment.
Serial Number Fitment Notice
This is a maintenance chemical rather than a model-specific hard part, so serial-number confirmation is generally less critical than it is for mechanical components. Even so, it is best to follow the storage procedure in the engine owner’s manual for the exact Mercury or MerCruiser application being serviced.
When This Part Needs Replacement
Use this product during winterization or before long-term storage to protect internal engine surfaces from corrosion while the engine sits idle. Mercury specifically positions it for off-season storage use.
Installation Notes
Mercury instructs users to follow the engine owner’s manual for use. Retail usage guidance commonly involves spraying the product into the air intake to fog the engine, then protecting cylinders before storage, but the correct procedure should always match the engine’s official service guidance.
Alternate / Superseded Part Numbers
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92-858081K03
Mercury also sells a closely related Quicksilver-branded version under 858081Q03, but for this listing the correct Mercury OEM number is 858081K03.
Parts Desk Insight
Fogging oil is one of those small seasonal items that can make a big difference on engines that sit for months. Its main job is not lubrication in normal operation, but corrosion protection during storage, especially on internal metal surfaces that would otherwise be exposed to moisture and air.
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.