Mercury / MerCruiser Quicksilver Engine Cleaner 858080KC3

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

• Part Number: 858080KC3 (often cataloged as 858080K03)

• Product Type: Internal engine / combustion chamber cleaner

• Size: 12 oz aerosol spray

• Brand: Mercury Marine / Quicksilver OEM

What It Does

Power Tune works by breaking down deposits that accumulate during normal engine operation.

It helps remove:

• Carbon deposits in combustion chambers

• Gum and varnish in fuel systems

• Deposits on pistons, valves, and exhaust ports

• 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:

• Mercury outboards (2-stroke and 4-stroke)

• MerCruiser sterndrive engines

• 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:

• Restore power in engines suffering from carbon buildup

• Clean engines during tune-ups

• Decarbonize 2-stroke outboards

• 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.