Mercury / MerCruiser Quicksilver Engine Cleaner — 858080KC3
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Mercury / MerCruiser Quicksilver Engine Cleaner — 858080KC3
The Mercury Quicksilver 858080KC3 Engine Cleaner (commonly listed as 858080K03 / 92-858080K03) is an OEM Power Tune internal engine cleaner designed to remove carbon, gum, and varnish deposits from gasoline engines. It is widely used on Mercury outboards and MerCruiser sterndrive engines to restore lost performance caused by combustion-chamber buildup.
Key Specifications
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Part Number: 858080KC3 (often cataloged as 858080K03)
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Product Type: Internal engine / combustion chamber cleaner
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Size: 12 oz aerosol spray
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Brand: Mercury Marine / Quicksilver OEM
What It Does
Power Tune works by breaking down deposits that accumulate during normal engine operation.
It helps remove:
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Carbon deposits in combustion chambers
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Gum and varnish in fuel systems
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Deposits on pistons, valves, and exhaust ports
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Build-up inside carburetors or injectors
Removing these deposits improves fuel/air flow, throttle response, and overall engine performance.
Compatible Engines
Safe for use in all gasoline marine engines, including:
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Mercury outboards (2-stroke and 4-stroke)
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MerCruiser sterndrive engines
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Carbureted and fuel-injected engines
It can also be used on other small gasoline engines such as motorcycles, ATVs, lawn equipment, and snowmobiles.
Typical Service Use
Technicians often use Power Tune to:
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Restore power in engines suffering from carbon buildup
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Clean engines during tune-ups
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Decarbonize 2-stroke outboards
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Clean carburetors and intake systems during maintenance or rebuilds
When sprayed into the intake of a running engine, the cleaner penetrates deposits and they are burned off after a short soak period.
⚠️ Service Tip:
Power Tune is an engine decarbonizer, not a fuel stabilizer. For fuel storage protection, Mercury recommends using Quickstor, and for routine fuel treatment Quickleen or Quickare.
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.